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Steam locomotive

Steam locomotive

Overview
A steam locomotive is a railway locomotive that produces its power through a steam engine
Steam engine
A steam engine is a heat engine that performs mechanical work using steam as its working fluid.Steam engines are external combustion engines, where the working fluid is separate from the combustion products. Non-combustion heat sources such as solar power, nuclear power or geothermal energy may be...

. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine. Both fuel and water supplies are carried with the locomotive, either on the locomotive itself or in wagons pulled behind.

Steam locomotives were first developed in Britain
United Kingdom of Great Britain and Ireland
The United Kingdom of Great Britain and Ireland was the formal name of the United Kingdom during the period when what is now the Republic of Ireland formed a part of it....

 and dominated railway transportation until the middle of the 20th century.
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Encyclopedia
A steam locomotive is a railway locomotive that produces its power through a steam engine
Steam engine
A steam engine is a heat engine that performs mechanical work using steam as its working fluid.Steam engines are external combustion engines, where the working fluid is separate from the combustion products. Non-combustion heat sources such as solar power, nuclear power or geothermal energy may be...

. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine. Both fuel and water supplies are carried with the locomotive, either on the locomotive itself or in wagons pulled behind.

Steam locomotives were first developed in Britain
United Kingdom of Great Britain and Ireland
The United Kingdom of Great Britain and Ireland was the formal name of the United Kingdom during the period when what is now the Republic of Ireland formed a part of it....

 and dominated railway transportation until the middle of the 20th century. From the early 1900s they were gradually superseded by electric
Electric locomotive
An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or an on-board energy storage device...

 and diesel locomotive
Diesel locomotive
A diesel locomotive is a type of railroad locomotive in which the prime mover is a diesel engine, a reciprocating engine operating on the Diesel cycle as invented by Dr. Rudolf Diesel...

s.

Origins





See also: History of rail transport
History of rail transport
The history of rail transport dates back nearly 500 years and includes systems with man or horse power and rails of wood or stone. Modern rail transport systems first appeared in England in the 1820s...

, :Category:Early steam locomotives


The earliest railways employed horses to draw carts along railed tracks
Rail tracks
The track on a railway or railroad, also known as the permanent way, is the structure consisting of the rails, fasteners, sleepers and ballast , plus the underlying subgrade...

.

As the development of steam engine
Steam engine
A steam engine is a heat engine that performs mechanical work using steam as its working fluid.Steam engines are external combustion engines, where the working fluid is separate from the combustion products. Non-combustion heat sources such as solar power, nuclear power or geothermal energy may be...

s progressed through the 18th century, various attempts were made to apply them to road and railway use. In 1784, William Murdoch
William Murdoch
William Murdoch was a Scottish engineer and long-term inventor.Murdoch was employed by the firm of Boulton and Watt and worked for them in Cornwall, as a steam engine erector for ten years, spending most of the rest of his life in Birmingham, England.He was the inventor of the oscillating steam...

, a Scottish
Scotland
Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

 inventor, built a prototype steam road locomotive. An early working model of a steam rail locomotive was designed and constructed by steamboat pioneer John Fitch
John Fitch (inventor)
John Fitch was an American inventor, clockmaker, and silversmith who, in 1787, built the first recorded steam-powered boat in the United States...

 in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 probably during the 1780s or 1790s.
His steam locomotive used interior bladed wheels guided by rails or tracks. The model still exists at the Ohio Historical Society
Ohio Historical Society
The Ohio Historical Society is a non-profit organization incorporated in 1885 as The Ohio State Archaeological and Historical Society "to promote a knowledge of archaeology and history, especially in Ohio"...

 Museum in Columbus.

The first full-scale working railway steam locomotive was built by Richard Trevithick
Richard Trevithick
Richard Trevithick was a British inventor and mining engineer from Cornwall. His most significant success was the high pressure steam engine and he also built the first full-scale working railway steam locomotive...

 in the United Kingdom
United Kingdom of Great Britain and Ireland
The United Kingdom of Great Britain and Ireland was the formal name of the United Kingdom during the period when what is now the Republic of Ireland formed a part of it....

 and, on 21 February 1804, the world's first railway journey took place as Trevithick's unnamed steam locomotive hauled a train along the tramway
Rail transport
Rail transport is a means of conveyance of passengers and goods by way of wheeled vehicles running on rail tracks. In contrast to road transport, where vehicles merely run on a prepared surface, rail vehicles are also directionally guided by the tracks they run on...

 of the Pen-y-darren
Penydarren
Penydarren Ironworks was the fourth of the great ironworks established at Merthyr Tydfil in South Wales.Built in 1784 by the brothers Samuel Homfray, Jeremiah Homfray, and Thomas Homfray, all sons of Francis Homfray of Stourbridge. Their father, Francis, for a time managed a nail warehouse there...

 ironworks, near Merthyr Tydfil
Merthyr Tydfil
Merthyr Tydfil is a town in Wales, with a population of about 30,000. Although once the largest town in Wales, it is now ranked as the 15th largest urban area in Wales. It also gives its name to a county borough, which has a population of around 55,000. It is located in the historic county of...

 in south Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...

 Accompanied with Andrew Vivian
Andrew Vivian
Andrew Vivian was a British mechanical engineer, inventor, and mine captain of the Dolcoath mine in Cornwall, England.In partnership with his cousin Richard Trevithick, the inventor of "high pressure" steam engines, and the entrepreneur Davis Giddy, Vivian financed the production of the first...

, it ran with mixed success. The design incorporated a number of important innovations that included using high-pressure steam which reduced the weight of the engine and increased its efficiency. Trevithick visited the Newcastle area in 1804 and he had a ready audience of colliery owners and engineers. The visit was so successful that the colliery railways in north-east England became the leading centre for experimentation and development of the steam locomotive. Then followed the successful twin-cylinder locomotive Salamanca
The Salamanca
Salamanca was the first commercially successful steam locomotive, built in 1812 by Matthew Murray of Holbeck, for the edge railed Middleton Railway between Middleton and Leeds. It was the first to have two cylinders...

by Matthew Murray
Matthew Murray
Matthew Murray was an English steam engine and machine tool manufacturer, who designed and built the first commercially viable steam locomotive, the twin cylinder Salamanca in 1812...

 for the edge railed rack and pinion
Rack and pinion
A rack and pinion is a type of linear actuator that comprises a pair of gears which convert rotational motion into linear motion. A circular gear called "the pinion" engages teeth on a linear "gear" bar called "the rack"; rotational motion applied to the pinion causes the rack to move, thereby...

 Middleton Railway
Middleton Railway
The Middleton Railway is the world's oldest continuously working railway. It was founded in 1758 and is now a heritage railway run by volunteers from The Middleton Railway Trust Ltd...

 in 1812. In 1825 George Stephenson
George Stephenson
George Stephenson was an English civil engineer and mechanical engineer who built the first public railway line in the world to use steam locomotives...

 built the Locomotion
Locomotion No 1
Locomotion No. 1 is an early British steam locomotive. Built by George and Robert Stephenson's company Robert Stephenson and Company in 1825, it hauled the first train on the Stockton and Darlington Railway on 27 September 1825....

for the Stockton and Darlington Railway
Stockton and Darlington Railway
The Stockton and Darlington Railway , which opened in 1825, was the world's first publicly subscribed passenger railway. It was 26 miles long, and was built in north-eastern England between Witton Park and Stockton-on-Tees via Darlington, and connected to several collieries near Shildon...

, north-east England, which was the first public steam railway in the world. In 1829, he built The Rocket
Stephenson's Rocket
Stephenson's Rocket was an early steam locomotive of 0-2-2 wheel arrangement, built in Newcastle Upon Tyne at the Forth Street Works of Robert Stephenson and Company in 1829.- Design innovations :...

which was entered in and won the Rainhill Trials
Rainhill Trials
The Rainhill Trials were an important competition in the early days of steam locomotive railways, run in October 1829 in Rainhill, Lancashire for the nearly completed Liverpool and Manchester Railway....

. This success led to Stephenson establishing his company as the pre-eminent builder of steam locomotives used on railways in the United Kingdom, United States and much of Europe. The Liverpool and Manchester Railway
Liverpool and Manchester Railway
The Liverpool and Manchester Railway was the world's first inter-city passenger railway in which all the trains were timetabled and were hauled for most of the distance solely by steam locomotives. The line opened on 15 September 1830 and ran between the cities of Liverpool and Manchester in North...

 opened a year later making exclusive use of steam power for both passenger and freight trains.

The United States started developing steam locomotives in 1829 with the Baltimore and Ohio Railroad
Baltimore and Ohio Railroad
The Baltimore and Ohio Railroad was one of the oldest railroads in the United States and the first common carrier railroad. It came into being mostly because the city of Baltimore wanted to compete with the newly constructed Erie Canal and another canal being proposed by Pennsylvania, which...

's Tom Thumb
Tom Thumb (locomotive)
Tom Thumb was the first American-built steam locomotive used on a common-carrier railroad. Designed and built by Peter Cooper in 1830, it was designed to convince owners of the newly formed Baltimore and Ohio Railroad to use steam engines...

. This was the first locomotive to run in America, although it was intended as a demonstration of the potential of steam traction, rather than as a revenue-earning locomotive. The first successful steam railway in the US was the South Carolina Railroad whose inaugural train ran on 25 December 1830 hauled by the Best Friend of Charleston
Best Friend of Charleston
The Best Friend of Charleston was a steam-powered railroad locomotive. It is widely acclaimed as the first locomotive to be built entirely within the United States. It also produced the first locomotive boiler explosion in the US.- History :...

. Many of the earliest locomotives for American railroads were imported from Great Britain, including the Stourbridge Lion
Stourbridge Lion
The Stourbridge Lion was a railroad steam locomotive. It was not only the first locomotive to be operated in the United States, it was also one of the first locomotives to operate outside of England, where it was manufactured in 1828....

and the John Bull
John Bull (locomotive)
John Bull is a British-built railroad steam locomotive that operated in the United States. It was operated for the first time on September 15, 1831, and it became the oldest operable steam locomotive in the world when the Smithsonian Institution operated it in 1981...

, but a domestic locomotive manufacturing industry was quickly established, with locomotives like the DeWitt Clinton
DeWitt Clinton (locomotive)
The DeWitt Clinton of the Mohawk and Hudson Railroad was the first steam locomotive to operate in the state of New York and the fourth built in the United States....

being built in the 1830s.

The first railway service in Continental Europe
Continental Europe
Continental Europe, also referred to as mainland Europe or simply the Continent, is the continent of Europe, explicitly excluding European islands....

 (or for that matter, anywhere outside the United Kingdom and the United States) was opened on 5 May 1835 in Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...

, between Mechelen
Mechelen
Mechelen Footnote: Mechelen became known in English as 'Mechlin' from which the adjective 'Mechlinian' is derived...

 and Brussels
Brussels
Brussels , officially the Brussels Region or Brussels-Capital Region , is the capital of Belgium and the de facto capital of the European Union...

. The name of the locomotive used was The Elephant.

In Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 the first working steam locomotive was a rack-and-pinion engine, similar to the Salamanca, designed by the British locomotive pioneer John Blenkinsop
John Blenkinsop
John Blenkinsop was an English mining engineer and an inventor of steam locomotives, who designed the first practical railway locomotive....

. Built in June 1816 by Johann Friedrich Krigar in the Royal Berlin Iron Foundry (Königlichen Eisengießerei zu Berlin), the locomotive ran on a circular track in the factory yard. It was the first locomotive to be built on the European mainland and the first steam-powered passenger service, because curious onlookers could ride in the attached coaches for a fee. It is portrayed on a New Year's badge for the Royal Foundry dated 1816. Another locomotive was built using the same system in 1817. They were to be used on pit railways in Königshütte and in Luisenthal on the Saar (today part of Völklingen
Völklingen
Völklingen is a town in the district of Saarbrücken, in Saarland, Germany. It is situated near the border with France, on the river Saar, approx. 10 km west of Saarbrücken....

), but neither could be returned to working order after being dismantled, moved and reassembled. On 7 December 1835 the Adler
Adler (locomotive)
The Adler was the first locomotive which was successfully commercially used for rail transport of passengers and goods in Germany. The rail vehicle was constructed and built in 1835 from the british railway pioneers George and Robert Stephenson in the english town Newcastle...

ran for the first time between Nuremberg
Nuremberg
Nuremberg[p] is a city in the German state of Bavaria, in the administrative region of Middle Franconia. Situated on the Pegnitz river and the Rhine–Main–Danube Canal, it is located about north of Munich and is Franconia's largest city. The population is 505,664...

 and Fürth
Fürth
The city of Fürth is located in northern Bavaria, Germany in the administrative region of Middle Franconia. It is now contiguous with the larger city of Nuremberg, the centres of the two cities being only 7 km apart....

 on the Bavarian Ludwig Railway. It was the 118th engine from the locomotive works of Robert Stephenson
Robert Stephenson
Robert Stephenson FRS was an English civil engineer. He was the only son of George Stephenson, the famed locomotive builder and railway engineer; many of the achievements popularly credited to his father were actually the joint efforts of father and son.-Early life :He was born on the 16th of...

 and stood under patent protection.
In 1837 the first steam railway started up in Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...

 on the Emperor Ferdinand Northern Railway between Vienna-Floridsdorf
Floridsdorf
Floridsdorf is the 21st district of Vienna, Austria .Floridsdorf is located in the northern part of Vienna.The District Office and the centre of Floridsdorf are located round Am Spitz, at the junction of Prager Straße and Brünner Straße .Since 2004, Floridsdorf has had its own tower: the...

 and Deutsch-Wagram
Deutsch-Wagram
Deutsch-Wagram is a city in Austria in the federal state of Lower Austria. It lies 15 km northeast of Vienna and has a population of 6,808 as of the 2001 census.- History :...

. The oldest continually working steam engine in the world also runs in Austria: the GKB 671
Südbahn Class 23 (old)
The steam locomotives of Südbahn Class 23 were goods train engines worked by the Austrian Southern Railway .The precursors to the Austrian Southern Railway had a very disparate fleet of goods locomotives....

 built in 1860 has never been taken out of service and is still used for special excursions.

In 1838 the third steam locomotive to be built in Germany, the Saxonia
Saxonia (locomotive)
The locomotive Saxonia was operated by the Leipzig-Dresden Railway Company and was the first practical working steam locomotive built in Germany. Its name means Saxony in Latin.- History :...

, was manufactured by the Maschinenbaufirma Übigau near Dresden
Dresden
Dresden is the capital city of the Free State of Saxony in Germany. It is situated in a valley on the River Elbe, near the Czech border. The Dresden conurbation is part of the Saxon Triangle metropolitan area....

, built by Prof. Johann Andreas Schubert
Johann Andreas Schubert
Johann-Andreas Schubert was a German general engineer , designer and university lecturer.- Life :Schubert was born on 19 March 1808 in Wernesgrün in the state of Saxony in Germany...

. The first independently designed locomotive in Germany was the Beuth built by August Borsig
August Borsig
Johann Friedrich August Borsig was a German businessman who founded the Borsig-Werke factory.Borsig was born in Breslau , the son of cuirassier and carpenter foreman Johann George Borsig...

 in 1841. In 1848 the first locomotive produced by Henschel-Werke in Kassel
Kassel
Kassel is a town located on the Fulda River in northern Hesse, Germany. It is the administrative seat of the Kassel Regierungsbezirk and the Kreis of the same name and has approximately 195,000 inhabitants.- History :...

, the Drache, was delivered.

The first railway line over Swiss territory was the Strasbourg
Strasbourg
Strasbourg is the capital and principal city of the Alsace region in eastern France and is the official seat of the European Parliament. Located close to the border with Germany, it is the capital of the Bas-Rhin département. The city and the region of Alsace are historically German-speaking,...

–Basle line opened in 1844. Three years later, in 1847, the first fully Swiss railway line, the Spanisch Brötli Bahn, from Zürich
Zürich
Zurich is the largest city in Switzerland and the capital of the canton of Zurich. It is located in central Switzerland at the northwestern tip of Lake Zurich...

 to Baden was opened.

Basic form



Boiler


The typical steam locomotive employs a steel fire-tube
Fire-tube boiler
A fire-tube boiler is a type of boiler in which hot gases from a fire pass through one or more tubes running through a sealed container of water...

 boiler
Boiler
A boiler is a closed vessel in which water or other fluid is heated. The heated or vaporized fluid exits the boiler for use in various processes or heating applications.-Materials:...

 that contains water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

 and steam
Steam
Steam is the technical term for water vapor, the gaseous phase of water, which is formed when water boils. In common language it is often used to refer to the visible mist of water droplets formed as this water vapor condenses in the presence of cooler air...

 under pressure. A firebox is normally located in the rear of the boiler (chimney or stack in front). The firebox has a water filled steel chamber surrounding the top and sides of the flame in the firebox. If wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...

 or coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...

 is used to make the fire
Fire
Fire is the rapid oxidation of a material in the chemical process of combustion, releasing heat, light, and various reaction products. Slower oxidative processes like rusting or digestion are not included by this definition....

 in the firebox it is built on a set of grate
Grate
*A grate is a frame of iron bars to hold fuel for a fire.*It may also refer to a covering of a drain, also called a grating.*The act of using a grater, a kitchen utensil.- People :*Don Grate US sportsman....

s where ashes may be separated from the burning fuel. These ashes must periodically be removed from the engine. If wood or coal are the fuel used in the firebox there is a door at the rear of the firebox that is opened to add more fuel. If oil
Oil
An oil is any substance that is liquid at ambient temperatures and does not mix with water but may mix with other oils and organic solvents. This general definition includes vegetable oils, volatile essential oils, petrochemical oils, and synthetic oils....

 is used there nearly always is a door for adjusting the air flow, maintenance or for cleaning the oil jets.

To extract even more heat, the smoke and hot gasses produced by combustion
Combustion
Combustion or burning is the sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat and conversion of chemical species. The release of heat can result in the production of light in the form of either glowing or a flame...

 in the firebox travel horizontally through a bundle of parallel tubes submerged in the water in the boiler from the front of the firebox to the front of the boiler. The heat extracted in the firebox and tubes in the boiler converts the water in the boiler to high-pressure steam. To minimize heat loss from the boiler it is normally surrounded with layers of insulation or lagging
Thermal insulation
Thermal insulation is the reduction of the effects of the various processes of heat transfer between objects in thermal contact or in range of radiative influence. Heat transfer is the transfer of thermal energy between objects of differing temperature...

.

The water and steam in the boiler are kept pressurized to raise the boiling temperature of the water and generate high-pressure steam. The amount of pressure in the boiler is monitored by the engineer or fireman by a gauge mounted in the cab. Excess steam pressure can be released manually or may blow off through a safety valve. Excessive pressure may cause the boiler to violently burst, resulting in injuries and fatalities to nearby individuals, as well as extensive damage to the locomotive itself and nearby structures.

At the front of the boiler is the smokebox
Smokebox
A smokebox is one of the major basic parts of a Steam locomotive exhaust system. Smoke and hot gases pass from the firebox through tubes where they pass heat to the surrounding water in the boiler. The smoke then enters the smokebox, and is exhausted to the atmosphere through the chimney .To assist...

, where exhaust steam is ejected into the chimney or stack, drawing the smoke and combustion gases through the fire tubes in the boiler and out the top of the chimney. The combustion in a typical steam engine is not very complete leading to the production of prodigious amounts of smoke, as well as sparks. This characteristic made these engines very dirty to live around, as well as being an acute hazard while passing through a forest, tunnel or snow shed.

The steam generated in the boiler is used to drive the locomotive and also for other purposes (whistles, brakes, pumps, passenger car heating, etc.). The constant use of steam requires the boiler to have water continually pumped into it (usually by automatic means). The source of this water is an unpressurized tank that is usually part of the locomotive's tender. Periodic stops are required to refill the tender.

During operation, the boiler's water level is constantly monitored, normally via a transparent tube referred to as a sight glass, or with a gauge. Maintaining a proper water level is crucial to the efficient and safe operation of the boiler. If the water level is too high, steam production is decreased, efficiency is lost and in extreme cases, water will be carried out with the steam into the cylinders, possibly causing mechanical damage. More seriously, if the water level gets too low, the crown (top) and/or side sheets of the firebox may become exposed. Without sufficient water to absorb the heat of combustion, the firebox sheets will soften and melt, resulting in high-pressure steam being ejected with tremendous force through the firebox and into the locomotive's cab.

Scale may build up in boiler to prevent proper heat transfer, and corrosion will eventually degrade the boiler's materials to the point where it needs to be rebuilt or replaced. Start up on a large engine may take hours of preliminary heating of the boiler water before sufficient steam is available. The steam engine in locomotives was a novel invention that took advantage of readily available fuels such as wood and coal. As new sources of energy were discovered such as petroleum, the steam engine was replaced by more efficient, less maintenance intensive internal combustion engines.

The boiler is typically placed horizontally. For locomotives designed to work on steep slopes, it may be placed vertically
Vertical boiler
A vertical boiler is a type of fire-tube or water-tube boiler where the boiler barrel is oriented vertically instead of the more common horizontal orientation...

 or mounted instead at an angle.

Steam circuit


The steam generated in the boiler fills the steam space above the water in the partially filled boiler. Its maximum working pressure is limited by spring-loaded safety valves. It is then collected either in a perforated tube fitted above the water level or from a dome that often houses the regulator valve, or throttle, the purpose of which is to control the amount of steam leaving the boiler. The steam then either travels directly along and down a steam pipe to the engine unit or may first pass into the wet header of a superheater
Superheater
A superheater is a device used to convert saturated steam or wet steam into dry steam used for power generation or processes. There are three types of superheaters namely: radiant, convection, and separately fired...

, the role of the latter being to improve thermal efficiency and eliminate water droplets suspended in the "saturated steam", the state in which it leaves the boiler. On leaving the superheater, the steam exits the dry header of the superheater and passing down a steam pipe entering the steam chests adjacent to the cylinders of a reciprocating engine. Inside each steam chest is a sliding valve that distributes the steam via ports that connect the steam chest to the ends of the cylinder space. The role of the valves is twofold: admission of each fresh dose of steam and exhaust of the used steam once it has done its work.

The cylinders are double acting, with steam admitted to each side of the piston in turn. In a two-cylinder locomotive, one cylinder is located on each side of the locomotive. The cranks are set 90° out of phase. During a full rotation of the driving wheel, steam provides four power strokes; each cylinder receives two injections of steam per revolution. The first stroke is to the front of the piston and the second stroke to the rear of the piston; hence two working strokes. Consequently two deliveries of steam onto each piston face in two cylinders generates a full revolution of the driving wheel. Each piston is connected to the driving axle on each side by a connecting rod, the driving wheels are connected together by coupling rod
Coupling rod
right|thumb|connecting rod and coupling rods attached to a small locomotive driving wheelA coupling rod or side rod connects the driving wheels of a locomotive. Steam locomotives in particular usually have them, but some diesel and electric locomotives, especially older ones and shunters, also have...

s to transmit power from the main driver to the other wheels. Note that at the two "dead centres", when the connecting rod is on the same axis as the crankpin on the driving wheel, the connecting rod applies no torque
Torque
Torque, moment or moment of force , is the tendency of a force to rotate an object about an axis, fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist....

 to the wheel. Therefore, if both cranksets could be at "dead centre" at the same time, and the wheels should happen to stop in this position, the locomotive could not be started moving. Therefore the crankpins are attached to the wheels at a 90° angle to each other, so only one side can be at dead centre at a time.

Each piston
Piston
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from...

 transmits power directly through a connecting rod
Connecting rod
In a reciprocating piston engine, the connecting rod or conrod connects the piston to the crank or crankshaft. Together with the crank, they form a simple mechanism that converts linear motion into rotating motion....

 (US: main rod) and a crankpin (US: wristpin) on the driving wheel
Driving wheel
On a steam locomotive, a driving wheel is a powered wheel which is driven by the locomotive's pistons...

 (US main driver) or to a crank
Crank (mechanism)
A crank is an arm attached at right angles to a rotating shaft by which reciprocating motion is imparted to or received from the shaft. It is used to change circular into reciprocating motion, or reciprocating into circular motion. The arm may be a bent portion of the shaft, or a separate arm...

 on a driving axle. The movement of the valves in the steam chest is controlled through a set of rods and linkages called the valve gear
Valve gear
The valve gear of a steam engine is the mechanism that operates the inlet and exhaust valves to admit steam into the cylinder and allow exhaust steam to escape, respectively, at the correct points in the cycle...

, actuated from the driving axle or else from the crankpin; the valve gear includes devices that allow reversing the engine, adjusting valve travel and the timing of the admission and exhaust events. The cut-off
Cutoff (steam engine)
In a steam engine, cutoff is the point in the piston stroke at which the inlet valve is closed. On a steam locomotive, the cutoff is controlled by the reverser....

 point determines the moment when the valve blocks a steam port, "cutting off" admission steam and thus determining the proportion of the stroke during which steam is admitted into the cylinder; for example a 50% cut-off admits steam for half the stroke of the piston. The remainder of the stroke is driven by the expansive force of the steam. Careful use of cut-off provides economical use of steam and, in turn, reduces fuel and water consumption. The reversing lever (US: Johnson bar
Johnson bar
A Johnson bar is a hand lever with several distinct positions and a positive latch to hold the lever in the selected position. The latch is typically activated with a spring-loaded squeeze handle on the lever so that only one hand is needed to release the latch, move the lever, then re-engage the...

), or screw-reverser, (if so equipped) that controls the cut-off therefore performs a similar function to a gearshift in an automobile
Automobile
An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...

 - maximum cut-off, providing maximum tractive effort
Tractive effort
As used in mechanical engineering, the term tractive force is the pulling or pushing force exerted by a vehicle on another vehicle or object. The term tractive effort is synonymous with tractive force, and is often used in railway engineering to describe the pulling or pushing capability of a...

 at the expense of efficiency, is used to pull away from a standing start, whilst a cut-off as low as 10% is used when cruising, providing reduced tractive effort with lower fuel/water consumption.



Exhaust steam is directed upwards to the atmosphere through the chimney, by way of a nozzle called a blastpipe
Blastpipe
The blastpipe is part of the exhaust system of a steam locomotive that discharges exhaust steam from the cylinders into the smokebox beneath the chimney in order to increase the draught through the fire.- History :...

 that gives rise to the familiar "chuffing" sound of the steam locomotive. The blastpipe is placed at a strategic point inside the smokebox that is at the same time traversed by the combustion gases drawn through the boiler and grate by the action of the steam blast. The combining of the two streams, steam and exhaust gases, is crucial to the efficiency of any steam locomotive and the internal profiles of the chimney, (or more strictly speaking, the ejector) require careful design and adjustment. This has been the object of intensive studies by a number of engineers (and almost totally ignored by others with sometimes catastrophic effect). The fact that the draught depends on the exhaust pressure means that power delivery and power generation are automatically self-adjusting and among other things, a balance has to be struck between obtaining sufficient draught for combustion whilst giving the exhaust gases and particles sufficient time to be consumed. In the past, fierce draught could lift the fire off the grate, or cause the ejection of unburnt particles of fuel, dirt and pollution for which steam locomotives had an unenviable reputation in the past. Moreover, the pumping action of the exhaust has the counter effect of exerting back pressure on the side of the piston receiving steam, thus slightly reducing cylinder power. Designing the exhaust ejector has become a specific science in which Chapelon
André Chapelon
André Chapelon was a noted French mechanical engineer and designer of advanced steam locomotives. Engineer of Ecole Centrale Paris, he was one of very few locomotive designers who brought a rigorous scientific method to their design, and he sought to apply up-to-date knowledge and theories in...

, Giesl
Adolph Giesl-Gieslingen
Adolph Giesl-Gieslingen was an Austrian locomotive designer and engineer.Giesl-Gieslingen was born in 1903 in Trient, Tirol, and studied at the Technical College in Vienna. In 1924 he published a technical article on smokebox design and chimneys...

 and Porta
Livio Dante Porta
Livio Dante Porta was an Argentine steam locomotive engineer. He is particularly remembered for his innovative modifications to existing locomotive systems in order to obtain higher performance, energy efficiency and reduced pollution. He developed the Kylpor and Lempor exhaust systems...

 were successive masters, and was largely responsible for spectacular improvements in thermal efficiency and a significant reduction in maintenance time and pollution. A similar system was used by some early gasoline/kerosene tractor
Tractor
A tractor is a vehicle specifically designed to deliver a high tractive effort at slow speeds, for the purposes of hauling a trailer or machinery used in agriculture or construction...

 manufacturers (Advance-Rumely
Advance-Rumely
The Advance-Rumely Company of La Porte, Indiana was organized in 1915 as a producer of many types of agricultural machinery, most notably threshing machines and large tractors...

/Hart-Parr) – the exhaust gas volume vented through a cooling tower meant that the steam exhaust helped draw more air past the radiator.

Chassis


The chassis or locomotive frame
Locomotive frame
A locomotive frame is the structure that forms the backbone of the railway locomotive, giving it strength and supporting the superstructure elements such as a cab, boiler or bodywork. The vast majority of locomotives have had a frame structure of some kind...

 is the principal structure onto which the boiler is mounted and which incorporates the various elements of the running gear. The boiler is rigidly mounted on a "saddle" beneath the smokebox and front of the boiler barrel, but the firebox at the rear is allowed to slide forward and back, to allow for expansion when hot.

European locomotives usually use "plate frames", where two vertical flat plates form the main chassis, with a variety of spacers and a buffer beam at each end to keep them apart. When inside cylinders are mounted between the frames, these are a single large casting that forms a major support to the frames. The axleboxes slide up and down to give some sprung suspension, against thickened webs attached to the frame, called "hornblocks".

For many years, in American practice used built-up bar frames with the "smokebox saddle/cylinder" structure and "drag beam" integrated therein, but from the late 1920s with the introduction of "superpower", the "cast-steel locomotive bed" became the norm, incorporating frames, spring hangers, motion brackets, smokebox saddle and cylinder blocks into a single complex, sturdy but heavy casting. André Chapelon
André Chapelon
André Chapelon was a noted French mechanical engineer and designer of advanced steam locomotives. Engineer of Ecole Centrale Paris, he was one of very few locomotive designers who brought a rigorous scientific method to their design, and he sought to apply up-to-date knowledge and theories in...

 developed a similar structure but of welded construction with around 30% saving in weight for the still-born 2-10-4 locomotives the construction of which was begun then abandoned in 1946.

Running gear



This includes the brake gear, wheel sets, axleboxes, springing and the "motion" that includes connecting rods and valve gear. The transmission of the power from the pistons to the rails and the behaviour of the locomotive as a vehicle, able to negotiate curves, points and irregularities in the track is of paramount importance. Because reciprocating power has to be directly applied to the rail from 0 rpm upwards, this poses unique problems of "adhesion" of the driving wheels to the smooth rail surface. Adhesive weight is the portion of the locomotive's weight bearing on the driving wheels. This is made more effective if a pair of driving wheels is able to make the most of its "axle load", i.e., its individual share of the adhesive weight. Locomotives with "compensating levers" connecting the ends of plate springs have often been deemed a complication but locomotives fitted with them have usually been less prone to loss of traction due to wheel-slip.

Locomotives with total adhesion, i.e., where all the wheels are coupled together, generally lack stability at speed. This makes desirable the inclusion of unpowered carrying wheels
Carrying wheels
The carrying wheels on a steam locomotive are those wheels that are not driven, i.e. they are uncoupled and run freely, unlike coupled or driving wheels. They are also described as running wheels and their axle may be called a carrying axle. Carrying wheels are referred to as leading wheels if they...

 mounted on two-wheeled trucks or four-wheeled bogie
Bogie
A bogie is a wheeled wagon or trolley. In mechanics terms, a bogie is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed in place, as on a cargo truck, mounted on a swivel, as on a railway carriage/car or locomotive, or sprung as in the suspension of a caterpillar...

s centred by springs that help to guide the locomotive through curves. These usually take the weight of the cylinders in front or of the firebox at the rear end when the width of this exceeds that of the mainframes. For multiple coupled wheels on a rigid chassis a variety of systems for controlled side-play exist.

Railroads typically wanted a locomotive with as few axles as possible. This would reduce the cost of maintenance. The number of axles required was dictated by the maximum axle loading of the railroad in question. A builder would typically add axles until the maximum weight on any one axle was acceptable to the railroad's maximum axle loading. A locomotive with a wheel arrangement of two lead axles, two drive axles, & one trailing axle was in actuality a high speed machine. Two lead axles were necessary to have good tracking at high speeds. Two drive axles had a lower reciprocating mass than three, four, five, or six coupled axles. They were thus able to turn very high speeds due to the lower reciprocating mass. A trailing axle was able to support a huge firebox. Hence most locomotives with the wheel arrangement of 4-4-2 (American Type Atlantic) were "free steamers" able to maintain steam pressure regardless of throttle setting.

Fuel and water


Generally, the largest locomotives are permanently coupled to a tender that carries the water and fuel. Often, locomotives working shorter distances do not have a tender and carry the fuel in a bunker, the water is carried in tanks placed next to the boiler either in 2 tanks alongside (pannier tank), one on top (saddle tank) or one underneath (well tank); these are called tank engines
Tank locomotive
A tank locomotive or tank engine is a steam locomotive that carries its water in one or more on-board water tanks, instead of pulling it behind it in a tender. It will most likely also have some kind of bunker to hold the fuel. There are several different types of tank locomotive dependent upon...

 and usually have a 'T' suffix added to the Whyte notation
Whyte notation
The Whyte notation for classifying steam locomotives by wheel arrangement was devised by Frederick Methvan Whyte and came into use in the early twentieth century encouraged by an editorial in American Engineer and Railroad Journal...

, e.g., 0-6-0T.

The fuel used depended on what was economically available to the railway. In the UK and parts of Europe, plentiful supplies of coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...

 made this the obvious choice from the earliest days of the steam engine. Until 1870, the majority of locomotives in the USA burnt wood but, as the Eastern forests were cleared, coal gradually became more important. Thereafter, coal became and remained the dominant fuel worldwide until the end of general use of steam locomotives. Bagasse
Bagasse
Bagasse is the fibrous matter that remains after sugarcane or sorghum stalks are crushed to extract their juice. It is currently used as a biofuel and as a renewable resource in the manufacture of pulp and paper products and building materials....

, a waste by-product of the refining process, was burned in sugar cane farming operations. In the USA, the ready availability of oil made it a popular steam locomotive fuel after 1900 for the southwestern railroads, particularly the Southern Pacific. In Victoria, Australia after World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, many steam locomotives were converted to heavy oil firing. German, Russian, Australian and British railways experimented using coal dust
Coal dust
Coal dust is a fine powdered form of coal, which is created by the crushing, grinding, or pulverizing of coal. Because of the brittle nature of coal, coal dust can be created during mining, transportation, or by mechanically handling coal.-Explosions:...

 to fire locomotives.

A number of tourist lines and heritage locomotives in Switzerland, Argentina and Australia have been using light diesel-type oil.

Water was supplied at stopping places and locomotive depots from a dedicated water tower
Water tower
A water tower or elevated water tower is a large elevated drinking water storage container constructed to hold a water supply at a height sufficient to pressurize a water distribution system....

 connected to water crane
Water crane
A water crane or standpipe is a device used for delivering a large volume of water into the tank or tender of a steam locomotive. As a steam locomotive consumes large quantities of water, water cranes were a vital part of railway station equipment, often situated at the end of a platform, so that...

s or gantries. In the UK, the USA and France, water troughs (US track pans) were provided on some main lines to allow locomotives to replenish their water supply without stopping. This was achieved by using a 'water scoop' fitted under the tender or the rear water tank in the case of a large tank engine; the fireman remotely lowered the scoop into the trough, the speed of the engine forced the water up into the tank, and the scoop was raised again once it was full.


Water is an essential element in the operation of a steam locomotive; because as Swengel argued:

it has the highest specific heat of any common substance; that is more thermal energy is stored by heating water to a given temperature than would be stored by heating an equal mass of steel or copper to the same temperature. In addition, the property of vapourising (forming steam) stores additional energy without increasing the temperature... water is a very satisfactory medium for converting thermal energy of fuel into mechanical energy


Swengel went on to note that "at low temperature and relatively low boiler outputs" good water and regular boiler washout was an acceptable practise, even though such maintenance was high. As steam pressures increased, however, a problem of "foaming" or "priming" developed in the boiler, wherein dissolved solids in the water formed "tough-skinned bubbles" inside the boiler, which in turn were carried into the steam pipes and could blow off the cylinder heads. To overcome the problem, hot mineral concentrated water was deliberately wasted (blowing down) from the boiler from time to time. Higher steam pressures required more blowing down of water out of the boiler. Oxygen generated by boiling water attacks the boiler and with increased steam pressures the rate of rust (iron oxide) generated inside the boiler increases. One way to help overcome the problem was water treatment. Swengel suggested that the problems around water contributed to the interest in electrification of railways.

In the 1970s, L.D. Porta
Livio Dante Porta
Livio Dante Porta was an Argentine steam locomotive engineer. He is particularly remembered for his innovative modifications to existing locomotive systems in order to obtain higher performance, energy efficiency and reduced pollution. He developed the Kylpor and Lempor exhaust systems...

 developed a sophisticated heavy duty chemical water treatment that not only keeps the inside of the boiler clean and prevents corrosion, but modifies the foam in such a way as to form a compact "blanket" on the water surface that filters the steam as it is produced, keeping it pure and preventing carry-over into the cylinders of water and suspended abrasive matter.

Crew


A steam locomotive is normally controlled from the boiler
Boiler
A boiler is a closed vessel in which water or other fluid is heated. The heated or vaporized fluid exits the boiler for use in various processes or heating applications.-Materials:...

's backhead
Backhead
In rail terminology, backhead refers to the wall of a steam locomotive's firebox in the cab of the locomotive. The locomotive's controls are mounted on the backhead....

 and the crew is usually protected from the elements by a cab. A crew of at least two people is normally required to operate a steam locomotive. One, the engineer
Railroad engineer
A railroad engineer, locomotive engineer, train operator, train driver or engine driver is a person who drives a train on a railroad...

 or driver
Railroad engineer
A railroad engineer, locomotive engineer, train operator, train driver or engine driver is a person who drives a train on a railroad...

, is responsible for controlling the locomotive's starting, stopping and speed, and the fireman or boilerman is responsible maintaining the fire, regulating steam pressure, and monitoring boiler and tender water levels. Due to the historical loss of operational infrastructure and staffing, preserved steam locomotives operating on the mainline will often have a support crew travelling with the train.

Fittings and appliances


All locomotives are fitted with a variety of appliances. Some of these relate directly to the operation of the steam engine; while others are for signalling, train control, or other purposes. In the United States the Federal Railroad Administration
Federal Railroad Administration
The Federal Railroad Administration is an agency in the United States Department of Transportation. The agency was created by the Department of Transportation Act of 1966...

 mandated the use of certain appliances over the years in response to safety concerns. The most typical appliances are as follows:

Steam pumps and injectors


Water (feedwater) must be delivered to the boiler to replace that which is exhausted as steam after delivering a working stroke to the pistons. As the boiler is under pressure during operation, feedwater must be forced into the boiler at a pressure that is greater than the steam pressure, necessitating the use some sort of pump. Early engines used pumps driven by the motion of the pistons (axle pumps). Later steam injectors replaced the pump, while some engines use turbopump
Turbopump
A turbopump is a gas turbine that comprises basically two main components: a rotodynamic pump and a driving turbine, usually both mounted on the same shaft, or sometimes geared together...

s. Standard practice evolved to use two independent systems for feeding water to the boiler. Vertical glass tubes, known as water gauges
Sight glass
A sight glass or water gauge is a transparent tube through which the operator of a tank or boiler can observe the level of liquid contained within.-Liquid in tanks:...

 or water glasses, show the level of water in the boiler and are carefully monitored at all times while the boiler is being fired.

Boiler lagging



Large amounts of heat are wasted if a boiler is not insulated. Early locomotives used shaped wooden battens fitted lengthways along the boiler barrel and held in place by metal bands. Improved insulating methods included: applying a thick paste containing a porous mineral, such as kieselgur or shaped blocks of insulating compound such as magnesia blocks were attached. In the latter days of steam, "mattresses" of stitched asbestos
Asbestos
Asbestos is a set of six naturally occurring silicate minerals used commercially for their desirable physical properties. They all have in common their eponymous, asbestiform habit: long, thin fibrous crystals...

 cloth were fixed stuffed with asbestos fibre (but on separators so as not quite to touch the boiler); however in most countries, asbestos is nowadays banned for health reasons. The most common modern day material is glass wool
Glass wool
Glass wool or fiberglass insulation is an insulating material made from fiberglass, arranged into a texture similar to wool. Glass wool is produced in rolls or in slabs, with different thermal and mechanical properties....

, or wrappings of aluminium foil.

The lagging is protected by a close-fitted sheet-metal casing known as boiler clothing or cleading.

Effective lagging is particularly important for fireless locomotive
Fireless locomotive
A fireless locomotive is a type of locomotive designed for use under conditions restricted by either the presence of flammable material or the need for cleanliness...

s; however in recent times under the influence of L.D. Porta, "exaggerated" insulation has been practised for all types of locomotive on all surfaces liable to dissipate heat, such as cylinder ends and facings between the cylinders and the mainframes. This considerably reduces engine warmup time with marked increase in overall efficiency.

Safety valves




Early locomotives were fitted with a valve controlled by a weight suspended from the end of a lever, the steam outlet being stopped by a cone-shaped valve. As there was nothing to prevent the weighted lever from bouncing when the locomotive ran over irregularities in the track, thus wasting steam, the weight was replaced by a more stable spring-loaded column, often supplied by Salter, a well-known spring scale
Spring scale
The spring scale apparatus is simply a spring fixed at one end with a hook to attach an object at the other. It works by Hooke's Law, which states that the force needed to extend a spring is proportional to the distance that spring is extended from its rest position...

 manufacturer. The danger of all these devices was that the driving crew could be tempted to add weight to the arm to increase pressure. Most boilers were from early times fitted with a tamper-proof "lockup" direct-loaded ball valve protected by a cowl. In the late 1850s, John Ramsbottom
John Ramsbottom (engineer)
John Ramsbottom was an English mechanical engineer who created many inventions for railways, including the piston ring, the Ramsbottom safety valve, the displacement lubricator, and the water trough.- Biography :...

 introduced a safety valve that became popular in Britain during the latter part of the 19th Century. Not only was this valve tamper-proof, but tampering by the driver could only have the effect of easing pressure. George Richardson's safety valve was an American invention introduced in 1875 and was so designed as to release the steam only at the moment when the pressure attained the maximum permitted. This type of valve is in almost universal use at present. The British Great Western Railway
Great Western Railway
The Great Western Railway was a British railway company that linked London with the south-west and west of England and most of Wales. It was founded in 1833, received its enabling Act of Parliament in 1835 and ran its first trains in 1838...

 was a notable exception to this rule retaining the direct loaded type until the end of its separate existence because it was considered that such a valve lost less pressure between opening and closing.

Pressure gauge



The earliest locomotives did not show the pressure of steam in the boiler, but it was possible to estimate this by the position of the safety valve arm which often extended onto the firebox back plate; gradations marked on the spring column gave a rough indication of the actual pressure. The promoters of the Rainhill trials
Rainhill Trials
The Rainhill Trials were an important competition in the early days of steam locomotive railways, run in October 1829 in Rainhill, Lancashire for the nearly completed Liverpool and Manchester Railway....

 urged that each contender have a proper mechanism for reading the boiler pressure and Stephenson
George Stephenson
George Stephenson was an English civil engineer and mechanical engineer who built the first public railway line in the world to use steam locomotives...

 devised a nine-foot vertical tube of mercury with a sight-glass at the top, mounted alongside the chimney, for the Rocket
Stephenson's Rocket
Stephenson's Rocket was an early steam locomotive of 0-2-2 wheel arrangement, built in Newcastle Upon Tyne at the Forth Street Works of Robert Stephenson and Company in 1829.- Design innovations :...

. The Bourdon tube gauge, in which the pressure straightens an oval-section, coiled tube of brass or bronze connected to a pointer, was introduced in 1849 and quickly gained acceptance. This is the device used today. Some locomotives have an additional pressure gauge in the steam chest. This helps the driver avoid wheel-slip at startup, by warning if the regulator opening is too great.

Spark arrestor and self-cleaning smokebox



Wood-burners emit large quantities of flying sparks which necessitate an efficient spark arresting device generally housed in the smokestack. Many types were fitted, the most common early type being the Bonnet stack that incorporated a cone-shaped deflector placed before the mouth of the chimney pipe plus a wire screen covering the wide stack exit; more efficient was the Radley and Hunter centrifugal type patented in 1850, (generally known as the diamond stack) incorporating baffles so orientated as to induce a swirl effect in the chamber that encouraged the embers to burn out and fall to the bottom as ash. In the self-cleaning smokebox the opposite effect was achieved: by allowing the flue gasses to strike a series of deflector plates, angled in such a way that the blast was not impaired, the larger particles were broken into small pieces that would be ejected with the blast, rather than settle in the bottom of the smokebox to be removed by hand at the end of the run. As with the arrestor, a screen was incorporated to retain any large embers.

Locomotives of the British Railways standard classes fitted with self-cleaning smokeboxes were identified by a small cast oval plate marked "S.C.", fitted at the bottom of the smokebox door. These engines required different disposal procedures and the 'S.C.' plate highlighted this need to depot staff.

Stokers


A factor that limits locomotive performance is the rate at which fuel is fed into the fire. In the early 20th century some locomotives became so large, that the fireman could not shovel coal fast enough. In the United States, various steam-powered mechanical stokers became standard equipment and were adopted and used elsewhere including Australia and South Africa.

Feedwater heating


Introducing cold water into a boiler reduces power, and from the 1920s a variety of heaters
Feedwater heater
A feedwater heater is a power plant component used to pre-heat water delivered to a steam generating boiler. Preheating the feedwater reduces the irreversibilities involved in steam generation and therefore improves the thermodynamic efficiency of the system...

 were incorporated. The most common type for locomotives was the exhaust steam feedwater heater that piped some of the exhaust through small tanks mounted on top of the boiler or smokebox or else into the tender tank; the warm water then had to be delivered to the boiler by a small auxiliary steam pump. The rare economiser type differed in that it extracted residual heat from the exhaust gases. An example of this is the pre-heater drum(s) found on the Franco-Crosti boiler
Franco-Crosti boiler
The Franco-Crosti boiler is a type of boiler used for steam locomotives. It was designed in the 1930s by Attilio Franco and Dr Piero Crosti, two engineers working for the Ferrovie dello Stato , the Italian state railway.- Purpose :...

.

The use of live steam and exhaust steam injectors also assists in the pre-heating of boiler feed water to a small degree, though there is no efficiency advantage to live steam injectors. Such pre-heating also reduces the thermal shock that a boiler might experience when cold water is introduced directly. This is further helped by the top feed where water is introduced to the highest part of the boiler and made to trickle over a series of trays. G.J. Churchward fitted this arrangement to the high end of his domeless coned boilers Other British lines such as the LBSCR fitted a few locomotives with the top feed inside a separate dome forward of the main one.

Condensers and water re-supply


Steam locomotives consume vast quantities of water because they operate on an open cycle, expelling their steam immediately after a single use rather than recycling it in a closed loop as stationary and marine steam engine
Marine steam engine
A marine steam engine is a reciprocating steam engine that is used to power a ship or boat. Steam turbines and diesel engines largely replaced reciprocating steam engines in marine applications during the 20th century, so this article describes the more common types of marine steam engine in use...

s do. Water was a constant logistical problem, and in some desert areas condensing engines were devised. These engines had huge radiators in their tenders and instead of exhausting steam out of the funnel it was captured and passed back to the tender and condensed. The cylinder lubricating oil was removed from the exhausted steam to avoid a phenomenon known as priming, a condition caused by foaming in the boiler which would allow water to be carried into the cylinders causing damage because of its incompressibility. The most notable engines employing condensers (Class 25
South African Class 25 4-8-4
Between 1953 and 1955 the South African Railways placed ninety Class 25 condensing steam locomotives with a 4-8-4 Northern wheel arrangement in service...

, the "puffers which never puff") worked across the Karoo
Karoo
The Karoo is a semi-desert region of South Africa. It has two main sub-regions - the Great Karoo in the north and the Little Karoo in the south. The 'High' Karoo is one of the distinct physiographic provinces of the larger South African Platform division.-Great Karoo:The Great Karoo has an area of...

 desert of South Africa, from the 1950 until the 1980s.

Some British and American locomotives were equipped with scoops which collected water from "water troughs" (US: "track pan
Track pan
A track pan or water trough is a device to enable a steam railway locomotive to replenish its water supply while in motion...

s") while in motion, thus avoiding stops for water. In the U.S., small communities often did not have refilling facilities. During the early days of railroading, the crew simply stopped next to a stream and filled the tender using leather buckets. This was known as “jerking water” and led to the term "jerkwater towns" (meaning a small town, a term which today is considered derisive). In Australia and South Africa, locomotives in drier regions operated with large oversized tenders  and some even had an additional water wagon, sometimes called a "canteen" or in Australia (particularly in New South Wales) a "water gin".

Steam locomotives working on underground railways (such as London's Metropolitan Railway
Metropolitan railway
Metropolitan Railway can refer to:* Metropolitan line, part of the London Underground* Metropolitan Railway, the first underground railway to be built in London...

) were fitted with condensing apparatus
Steam locomotive condensing apparatus
A steam locomotive condensing apparatus differs in purpose from the usual closed cycle steam engine condenser, in that its function is primarily either to recover water, or to avoid excessive emissions to the atmosphere, rather than maintaining a vacuum to improve both efficiency and power...

 for a different, but obvious, reason. These were still being used between King's Cross and Moorgate
Moorgate station
Moorgate station is a central London railway terminus and London Underground station on Moorgate in the City of London; it provides National Rail services by First Capital Connect for Hertford, Welwyn Garden City and Letchworth and also serves the Circle, Hammersmith & City, Metropolitan Lines and...

 into the early 1960s.

Braking


Locomotives have their own braking system, independent from the rest of the train. Locomotive brakes employ large shoes which press against the driving wheel treads. With the advent of air brakes
Air brake (rail)
An air brake is a conveyance braking system actuated by compressed air. Modern trains rely upon a fail-safe air brake system that is based upon a design patented by George Westinghouse on March 5, 1872. The Westinghouse Air Brake Company was subsequently organized to manufacture and sell...

, a separate system also allowed the driver to control the brakes on all cars. These systems require steam-powered compressors, which are mounted on the side of the boiler or on the smokebox front. Almost all of these compressors were of the Westinghouse
Westinghouse Air Brake Company
The railway air brake was invented by George Westinghouse of New York state in 1869. Soon after, he moved to Pittsburgh, Pennsylvania, where he established the Westinghouse Air Brake Company on September 28, 1869...

 single-stage or cross-compound variety. Such systems operated in the United States, Canada, Australia and New Zealand.

An alternative to the air brake is the vacuum brake
Vacuum brake
The vacuum brake is a braking system employed on trains and introduced in the mid-1860s. A variant, the automatic vacuum brake system, became almost universal in British train equipment and in those countries influenced by British practice. Vacuum brakes also enjoyed a brief period of adoption in...

, in which a steam-operated ejector
Aspirator
An aspirator, also called an eductor-jet pump or filter pump, is a device that produces vacuum by means of the Venturi effect. In an aspirator, fluid flows through a tube which then narrows. When the tube narrows, the fluid's speed increases, and because of the Venturi effect, its pressure...

 is mounted on the engine instead of the air pump, to create vacuum and release the brakes. A secondary ejector or crosshead vacuum pump is used to maintain the vacuum in the system against the small leaks in the pipe connections between carriages and wagons. Vacuum systems existed on British, Indian and South African rail networks.

Steam locomotives are nearly always fitted with sandboxes
Sandbox (railways)
A sandbox is a container on most locomotives and self propelled multiple units, or trams, that run on tramways and adhesion railways...

 from which sand can be delivered to the rails to improve traction
Traction (engineering)
Traction refers to the maximum frictional force that can be produced between surfaces without slipping.The units of traction are those of force, or if expressed as a coefficient of traction a ratio.-Traction:...

 and braking in wet or icy weather. On American locomotives the sandboxes, or sand domes, are usually mounted on top of the boiler. In Britain, the limited loading gauge
Loading gauge
A loading gauge defines the maximum height and width for railway vehicles and their loads to ensure safe passage through bridges, tunnels and other structures...

 precludes this, so the sandboxes are mounted just above, or just below, the running plate.

Lubrication



The pistons and valves on the earliest locomotives were lubricated
Lubrication
Lubrication is the process, or technique employed to reduce wear of one or both surfaces in close proximity, and moving relative to each another, by interposing a substance called lubricant between the surfaces to carry or to help carry the load between the opposing surfaces. The interposed...

 by the enginemen dropping a lump of tallow
Tallow
Tallow is a rendered form of beef or mutton fat, processed from suet. It is solid at room temperature. Unlike suet, tallow can be stored for extended periods without the need for refrigeration to prevent decomposition, provided it is kept in an airtight container to prevent oxidation.In industry,...

 down the blast pipe.

As speeds and distances increased, mechanisms were developed that injected thick mineral oil into the steam supply. The first, a displacement lubricator
Displacement lubricator
A Mechanical lubricator, or automatic lubricator, is a device fitted to a steam engine to supply lubricating oil to the cylinders and, sometimes, the bearings and axle box mountings as well. There are various types of mechanical lubricator....

, mounted in the cab, uses a controlled stream of steam condensing into a sealed container of oil. Water from the condensed steam displaces the oil into pipes. The apparatus is usually fitted with sight-glasses to confirm the rate of supply. A later method uses a mechanical pump worked from one of the crossheads. In both cases, the supply of oil is proportional to the speed of the locomotive.

Lubricating the frame components (axle bearings, horn blocks and bogie
Bogie
A bogie is a wheeled wagon or trolley. In mechanics terms, a bogie is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed in place, as on a cargo truck, mounted on a swivel, as on a railway carriage/car or locomotive, or sprung as in the suspension of a caterpillar...

 pivots) depends on capillary action
Capillary action
Capillary action, or capilarity, is the ability of a liquid to flow against gravity where liquid spontanously rise in a narrow space such as between the hair of a paint-brush, in a thin tube, or in porous material such as paper or in some non-porous material such as liquified carbon fiber, or in a...

: trimmings of worsted yarn
Worsted
Worsted , is the name of a yarn, the cloth made from this yarn, and a yarn weight category. The name derives from the village of Worstead in the English county of Norfolk...

 are trailed from oil reservoirs into pipes leading to the respective component. The rate of oil supplied is controlled by the size of the bundle of yarn and not the speed of the locomotive, so it is necessary to remove the trimmings (which are mounted on wire) when stationary. However, at regular stops (such as a terminating station platform) oil finding its way onto the track can still be a problem.

Crank pin and crosshead bearings carry small cup-shaped reservoirs for oil. These have feed pipes to the bearing surface that start above the normal fill level, or are kept closed by a loose-fitting pin, so that only when the locomotive is in motion does oil enter. In United Kingdom practice the cups are closed with simple corks, but these have a piece of porous cane pushed through them to admit air. It is customary for a small capsule of pungent oil (aniseed or garlic) to be incorporated in the bearing metal to warn if the lubrication fails and excess heating or wear occurs.

Blower


When the locomotive is running under power, a draught on the fire is created by the exhaust steam directed up the chimney by the blastpipe. Without draught, the fire will quickly die down and steam pressure will fall. When the locomotive is stopped, or coasting with the regulator closed, there is no exhaust steam to create a draught, so the draught is maintained by means of the blower. This is a ring placed either around the base of the chimney, or around the blast pipe orifice, containing several small steam nozzles directed up the chimney. These nozzles are fed with steam directly from the boiler, controlled by the blower valve. When the regulator is open, the blower valve is closed; when the driver intends to close the regulator, he will first open the blower valve. It is important that the blower be opened before the regulator is closed, since without draught on the fire, there may be backdraught – air from the atmosphere blows down the chimney, causing the flow of hot gases through the boiler tubes to be reversed, with the fire itself being blown through the firehole onto the footplate, with serious consequences for the crew. The risk of backdraught is higher when the locomotive enters a tunnel because of the pressure shock. The blower is also used to create draught when steam is being raised at the start of the locomotive's duty; at any time when the driver needs to increase the draught on the fire; and to clear smoke from the driver's line of vision.

Buffers


In British and European practice, the locomotive usually had buffers
Buffer (rail transport)
A buffer is a part of the buffers-and-chain coupling system used on the railway systems of many countries, among them most of those in Europe, for attaching railway vehicles to one another....

 at each end to absorb compressive loads ("buffets"). The tensional load of drawing the train (draft force) is carried by the coupling
Coupling (railway)
A coupling is a mechanism for connecting rolling stock in a train. The design of the coupler is standard, and is almost as important as the railway gauge, since flexibility and convenience are maximised if all rolling stock can be coupled together.The equipment that connects the couplings to the...

 system. Together these control slack between the locomotive and train, absorb minor impacts, and provide a bearing point for pushing movements.

In American practice all of the forces between the locomotive and cars are handled through the coupler and its associated draft gear
Coupling (railway)
A coupling is a mechanism for connecting rolling stock in a train. The design of the coupler is standard, and is almost as important as the railway gauge, since flexibility and convenience are maximised if all rolling stock can be coupled together.The equipment that connects the couplings to the...

, which allows some limited slack movement. Small dimples called "poling pockets" at the front and rear corners of the locomotive allowed cars to be pushed on an adjacent track using a pole braced between the locomotive and the cars. In Britain and Europe, American style 'buckeye' and other couplers that also handle forces between items of rolling stock have become increasingly popular.

Pilots


A pilot
Pilot (locomotive)
In railroading, the pilot is the device mounted at the front of a locomotive to deflect obstacles from the track that might otherwise derail the train. In some countries it is also called cowcatcher or cattle catcher....

 was usually fixed to the front end of locomotives, although in European and a few other railway systems, such as New South Wales
Rail transport in New South Wales
The Australian state of New South Wales has an extensive network of railways, which were integral to the growth and development of the state. The vast majority of railway lines were government built and operated, but there were also several private railways, some of which operate to this...

, they were considered unnecessary. Plough-shaped, and called cow catchers, they were quite large and were designed to remove obstacles from the track such as cattle, bison, other animals or tree limbs. Though unable to "catch" stray cattle these distinctive items remained on locomotives until the end of steam. Switching engines usually replaced the pilot with small steps, known as footboards. Many systems used the pilot and other design features to produce a distinctive appearance.

Headlights


When night operations began, railway companies in some countries equipped their locomotives with lights to allow the driver to see what lay ahead of the train or to enable others to see the locomotive. Originally headlights were oil or acetylene
Acetylene
Acetylene is the chemical compound with the formula C2H2. It is a hydrocarbon and the simplest alkyne. This colorless gas is widely used as a fuel and a chemical building block. It is unstable in pure form and thus is usually handled as a solution.As an alkyne, acetylene is unsaturated because...

 lamps, but when electric arc lamp
Arc lamp
"Arc lamp" or "arc light" is the general term for a class of lamps that produce light by an electric arc . The lamp consists of two electrodes, first made from carbon but typically made today of tungsten, which are separated by a gas...

s became available in the late 1880s, they quickly replaced the older types.

Britain did not adopt bright headlights as they would affect night-adapted vision
Adaptation (eye)
In ocular physiology, adaptation is the ability of the eye to adjust to various levels of darkness and light.-Efficacy:The human eye can function from very dark to very bright levels of light; its sensing capabilities reach across nine orders of magnitude. This means that the brightest and the...

 and so could mask the low-intensity oil lamps used in the semaphore signals and at each end of trains, increasing the danger of missing signals especially on busy tracks. In any case, trains' stopping distances were normally much greater than the range of headlights, and the railways were well-signalled and fully fenced to prevent livestock and people from straying onto them. Thus low-intensity oil lamps continued to be used, positioned on the front of locomotives to indicate the class of each train. Four 'lamp irons' were provided (brackets on which to place the lamps): one below the chimney and three evenly spaced across the top of the buffer beam. The exception to this was the Southern Railway and its constituents, who added an extra lamp iron each side of the smokebox, and the arrangement of lamps (or in daylight, white circular plates) told railway staff the origin and destination of the train. (In all cases, equivalent lamp irons were also provided on the rear of the locomotive or tender for when the locomotive was running tender- or bunker-first.)

In some countries heritage steam operation continues on the national network. Some railway authorities have mandated powerful headlights on at all times, including during daylight. This was to further inform the public or track workers of any active trains.

Bells and whistles



Locomotives used bells and steam whistles from earliest days. In the United States, India and Canada bells warned of a train in motion. In Britain, where all lines are by law fenced throughout, bells were only a requirement on railways running on a road (i.e., not fenced off), for example a tramway along the side of the road or in a dockyard. Consequently only a minority of locomotives in the UK carried bells. Whistles are used to signal personnel and give warnings. Depending on the terrain the locomotive was being used in the whistle could be designed for long distance warning of impending arrival, or more for localised use.

Early bells and whistles were sounded through pull-string cords and levers. Automatic bell ringers came into widespread use in the U.S. after 1910.

Automatic control


From early in the 20th century operating companies in such countries as Germany and Britain began to fit locomotives with in-cab signalling (AWS)
Automatic Warning System
The Automatic Warning System is a form of limited cab signalling and train protection system introduced in 1956 in the United Kingdom to help train drivers observe and obey signals. It was based on a 1930 system developed by Alfred Ernest Hudd and marketed as the "Strowger-Hudd" system...

 which automatically applied the brakes when a signal was passed at "caution". In Britain these became mandatory in 1956. In the United States, the Pennsylvania Railroad
Pennsylvania Railroad
The Pennsylvania Railroad was an American Class I railroad, founded in 1846. Commonly referred to as the "Pennsy", the PRR was headquartered in Philadelphia, Pennsylvania....

 also fitted their locomotives with such devices.

Booster engines


In the United States and Australia the trailing truck was often equipped with an auxiliary steam engine which provided extra power for starting. This booster engine
Booster engine
A booster engine for steam locomotives is a small two-cylinder steam engine back-gear-connected to the trailing truck axle on the locomotive or, if none, the lead truck on the tender. A rocking idler gear permits it to be put into operation by the engineer...

 was set to cut out automatically at a certain speed. On the narrow gauged New Zealand railway system, six Kb 4-8-4 locomotives had boosters; the only gauge engines in the world to have such equipment.

Variations


Numerous variations to the simple locomotive occurred as railways attempted to improve efficiency and performance.

Cylinders


Early steam locomotives had two cylinders, one either side, and this practice persisted as the simplest arrangement. The cylinders could be mounted between the main frames (known as 'inside' cylinders), or mounted outside the frames and driving wheels ('outside' cylinders). Inside cylinders are driven by cranks built into the driving axle; outside cylinders are driven by cranks on extensions to the driving axles.

Later designs employed three or four cylinders, mounted both inside and outside the frames, for a more even power cycle and greater power output. This was at the expense of more complicated valve gear and increased maintenance requirements. In some cases the third cylinder was added 'inside' simply to allow for smaller diameter outside cylinders, and hence reduce the width of the locomotive for use on lines with a restricted loading gauge
Loading gauge
A loading gauge defines the maximum height and width for railway vehicles and their loads to ensure safe passage through bridges, tunnels and other structures...

, for example the SR K1 and U1 classes.

Most British express passenger locomotives built from about 1930 to 1950 were 4-6-0 or 4-6-2 types with three or four cylinders (e.g., GWR 6000 Class
GWR 6000 Class
The Great Western Railway 6000 Class or King is a class of 4-6-0 steam locomotive designed for express passenger work. With the exception of one Pacific , they were the largest locomotives the GWR built. They were named after kings of the United Kingdom and of England, beginning with the reigning...

, LMS Coronation Class, SR Merchant Navy Class
SR Merchant Navy class
The SR Merchant Navy class , was a class of air-smoothed 4-6-2 Pacific steam locomotives designed for the Southern Railway of the United Kingdom by Oliver Bulleid...

, LNER Gresley Class A3
LNER Gresley Classes A1 and A3
The London and North Eastern Railway LNER Gresley Classes A1 and A3 locomotives represented two distinct stages in the history of the British 4-6-2 "Pacific" steam locomotives designed by Nigel Gresley...

). From 1951, all but one of the 999 new British Rail standard class steam locomotives of all types from express passenger and heavy freight to smaller mixed traffic tank locomotives used 2-cylinder configurations for easier maintenance.

Valve gear



Numerous technological advances improved the steam engine. Early locomotives used simple valve gear that gave full power in either forward or reverse. Soon Stephenson valve gear
Stephenson valve gear
The Stephenson valve gear or Stephenson link or shifting link is a simple design of valve gear that was widely used throughout the world for all kinds of steam engine. It is named after Robert Stephenson but was actually invented by his employees....

 allowed the driver to control cut-off; this was largely superseded by Walschaerts valve gear and similar patterns. Early locomotive designs using slide valves
D slide valve
The slide valve is a rectilinear valve used to control the admission of steam into, and emission of exhaust from, the cylinder of a steam engine.-Use:...

 and outside admission were easy to construct, but inefficient and prone to wear. Eventually, slide valves were superseded by inside admission piston valves, though there were attempts to apply poppet valve
Poppet valve
A poppet valve is a valve consisting of a hole, usually round or oval, and a tapered plug, usually a disk shape on the end of a shaft also called a valve stem. The shaft guides the plug portion by sliding through a valve guide...

s (common by then on stationary engines) in the 20th century. Stephenson valve gear was generally placed within the frame and was difficult to access for maintenance; later patterns applied outside the frame, were readily visible and maintained.

Compounding



From 1876, compound locomotives came on the scene, which used the engine's steam twice. There were many compound locomotives especially where long periods of continuous efforts were needed. Compounding was an essential ingredient of the quantum leap in power achieved by André Chapelon
André Chapelon
André Chapelon was a noted French mechanical engineer and designer of advanced steam locomotives. Engineer of Ecole Centrale Paris, he was one of very few locomotive designers who brought a rigorous scientific method to their design, and he sought to apply up-to-date knowledge and theories in...

's rebuilds from 1929. A common application was to articulated locomotive, the most common being that of Anatole Mallet
Anatole Mallet
Jules T. Anatole Mallet was a Swiss mechanical engineer, who was the inventor of the first successful compound system for a railway steam locomotive, patented in 1874....

 in which the high-pressure stage was attached directly to the boiler frame; in front of this was pivoted a low-pressure engine on its own frame, taking the exhaust from the rear engine.

Articulated locomotives



More powerful locomotives also tend to be longer, but long, rigid-framed designs are impractical for the tight curves frequently found on narrow gauge railways. Various designs of articulated locomotive
Articulated locomotive
Articulated locomotive usually means a steam locomotive with one or more engine units which can move independent of the main frame. This is done to allow a longer locomotive to negotiate tighter curves...

 were developed to overcome this problem. The Mallet
Mallet locomotive
The Mallet Locomotive is a type of articulated locomotive, invented by a Swiss engineer named Anatole Mallet ....

 and the Garratt
Garratt
A Garratt is a type of steam locomotive that is articulated in three parts. Its boiler is mounted on the centre frame, and two steam engines are mounted on separate frames, one on each end of the boiler. Articulation permits larger locomotives to negotiate curves and lighter rails that might...

 were the two most popular, both using a single boiler and two engines (sets of cylinders and driving wheels) – the Garratt having two power bogies, the Mallet having one. There were also a few examples of "triplex
Triplex
Triplex may refer to:* Triplex , a dwelling composed of three units* Triplex , a French comedy film* Triplex , a family of typefaces designed by Zuzana Licko for Emigre in 1989...

" locomotives that had a third engine under the tender. Both the front and tender engines were low-pressure compounded, though they could be operated simple (high-pressure) for starting off. Other, less common, variations included the Fairlie locomotive, which had two boilers back-to-back on a common frame, with two separate power bogies.

Duplex types


Duplex locomotive
Duplex locomotive
A duplex locomotive is a steam locomotive that divides the driving force on its wheels by using two pairs of cylinders rigidly mounted to a single locomotive frame; it is not an articulated locomotive...

s with two engines in one rigid frame were also tried, but were not notably successful. For example, the 4-4-4-4
4-4-4-4
A 4-4-4-4 steam locomotive, in the Whyte notation for describing locomotive wheel arrangements, has a four-wheel leading truck, two sets of four driving wheels, and a four-wheel trailing truck.Other equivalent classifications are:...

 Pennsylvania Railroad's T1 class
PRR T1
The Pennsylvania Railroad's 52 T1 class duplex-drive 4-4-4-4 steam locomotives, introduced in 1942 and 1946 , were their last-built steam locomotives and their most controversial. They were ambitious, technologically sophisticated, powerful, fast, and uniquely streamlined by Raymond Loewy...

, designed for very fast running, suffered recurring and ultimately unfixable slippage problems throughout their careers.

Geared locomotives



For uses where a high starting torque and low speed were required, the conventional direct drive approach was inadequate. "Geared" steam locomotives, such as the Shay
Shay locomotive
The Shay locomotive was the most widely used geared steam locomotive. The locomotives were built to the patents of Ephraim Shay, who has been credited with the popularization of the concept of a geared steam locomotive...

, the Climax
Climax locomotive
A Climax locomotive is a type of geared steam locomotive in which the two steam cylinders were attached to a transmission located under the center of the boiler. This transmits power to driveshafts running to the front and rear trucks....

 and the Heisler
Heisler locomotive
The Heisler locomotive was the last variant of the three major types of geared steam locomotive, Charles L. Heisler receiving a patent for the design in 1892 following the construction of a prototype in 1891. Somewhat similar to a Climax locomotive, Heisler's design featured two cylinders canted...

, were developed to meet this need on industrial, logging, mine and quarry railways. The common feature of these three types was the provision of reduction gearing and a drive shaft between the crankshaft and the driving axles. This arrangement allowed the engine to run at a much higher speed than the driving wheels, compared to the conventional design, where the ratio is 1:1.

Cab forward


In the United States on the Southern Pacific Railroad
Southern Pacific Railroad
The Southern Pacific Transportation Company , earlier Southern Pacific Railroad and Southern Pacific Company, and usually simply called the Southern Pacific or Espee, was an American railroad....

 a series of cab forward
Cab forward
The term cab forward refers to various rail and road vehicle designs which place the driver's compartment substantially farther towards the front than is common practice.- Rail locomotives :...

 locomotives had the cab and the firebox at the front of the locomotive and the tender behind the smokebox
Smokebox
A smokebox is one of the major basic parts of a Steam locomotive exhaust system. Smoke and hot gases pass from the firebox through tubes where they pass heat to the surrounding water in the boiler. The smoke then enters the smokebox, and is exhausted to the atmosphere through the chimney .To assist...

, so that the engine appeared to run backwards. This was only possible by using oil-firing. Southern Pacific selected this design to provide smoke-free breathing for the engine driver as they went through the SP's numerous mountain tunnels and snow sheds. Another variation was the Camelback locomotive
Camelback locomotive
A camelback locomotive is a type of steam locomotive with the driving cab placed in the middle, astride the boiler...

 with the cab half-way along the boiler. In England, Oliver Bulleid
Oliver Bulleid
Oliver Vaughan Snell Bulleid was a British railway and mechanical engineer best known as the Chief Mechanical Engineer of the Southern Railway between 1937 and the 1948 nationalisation, developing many well-known locomotives.- Early life and Great Northern Railway :He was born in Invercargill,...

 developed the SR Leader class
SR Leader Class
The Leader was a class of experimental 0-6-6-0T articulated steam locomotive, produced in the United Kingdom to the design of the innovative engineer Oliver Bulleid. The Leader was an attempt to extend the life of steam traction by eliminating many of the operational drawbacks associated with...

 locomotive during the nationalisation process in the late 1940s. The locomotive was heavily tested but several design faults (like coal firing and sleeve valves) meant this locomotive and the other part-built locomotives were scrapped. The cab-forward design was taken by Bulleid to Ireland when he moved to after nationalisation where he developed the 'turfburner'. This locomotive was more successful but was scrapped with the dieselisation
Dieselisation
Dieselisation or dieselization is a term generally used for the increasingly common use of diesel fuel in vehicles, as opposed to gasoline or steam engines.-Water Transport:...

 of the Irish railways.

The only preserved cab forward locomotive is Southern Pacific 4294
Southern Pacific 4294
Southern Pacific 4294 was the last steam locomotive ordered new by Southern Pacific Railroad . It was built by Baldwin Locomotive Works in March 1944, and was used hauling SP's trains over the Sierra Nevada Mountains, often working on Donner Pass in California.- Construction and use :4294 was the...

 in Sacramento, California
Sacramento, California
Sacramento is the capital city of the U.S. state of California and the county seat of Sacramento County. It is located at the confluence of the Sacramento River and the American River in the northern portion of California's expansive Central Valley. With a population of 466,488 at the 2010 census,...

, US.

In France, the three Heilmann locomotive
Heilmann locomotive
The Heilmann locomotives were a series of three experimental steam-electric locomotives produced in the 1890s for the French Chemins de Fer de l'Ouest . A prototype was built in 1894 and two larger locomotives were built in 1897...

s were a cab forward design.

Steam turbines



Steam turbines were one of the experiments in improving the operation and efficiency of steam locomotives. Experiments with steam turbine
Steam turbine locomotive
A steam turbine locomotive is a steam locomotive which transmits steam power to the wheels via a steam turbine. Numerous attempts at this type of locomotive were made, mostly without success...

s using direct-drive and electrical transmissions, in different countries, proved mostly unsuccessful. The London, Midland and Scottish Railway
London, Midland and Scottish Railway
The London Midland and Scottish Railway was a British railway company. It was formed on 1 January 1923 under the Railways Act of 1921, which required the grouping of over 120 separate railway companies into just four...

 also built Turbomotive
LMS Turbomotive
The Turbomotive was a modified Princess Royal Class steam locomotive designed by William Stanier and built by the London, Midland and Scottish Railway in 1935. It used turbines instead of cylinders...

, a largely successful attempt to prove the efficiency of steam turbines. Had it not been for the outbreak of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, more may have been built. The Turbomotive ran from 1935 to 1949, when it was rebuilt into a conventional locomotive because replacement of many parts was required, an uneconomical proposition for a 'one-off' locomotive. In the United States the Union Pacific, Chesapeake and Ohio
Chesapeake and Ohio Railway
The Chesapeake and Ohio Railway was a Class I railroad formed in 1869 in Virginia from several smaller Virginia railroads begun in the 19th century. Led by industrialist Collis P...

, and Norfolk & Western (N&W) railways all built turbine-electric locomotives. The Pennsylvania Railroad
Pennsylvania Railroad
The Pennsylvania Railroad was an American Class I railroad, founded in 1846. Commonly referred to as the "Pennsy", the PRR was headquartered in Philadelphia, Pennsylvania....

 (PRR) also built turbine locos but with a direct-drive gearbox. However, all designs failed due to dust, vibration, design flaws, or inefficiency at lower speeds. The last one in service was the N&W's, retired in January 1958. The only truly successful design was the TGOJ MT3, used for hauling iron ore from Grängesberg
Grängesberg
Grängesberg is a locality situated in Ludvika Municipality, Dalarna County, Sweden with 3,532 inhabitants in 2005.The town was earlier dominated by iron-ore extraction at Grängesberg ore field from the 16th century to 1989...

 to the ports of Oxelösund
Oxelösund
Oxelösund is a locality and the seat of Oxelösund Municipality in Södermanland County, Sweden with 10,843 inhabitants in 2005.- History :The harbour at Oxelösund has been used for at least 500 years. In the 19th century, an increased extraction from the Mining district of Central Sweden , made...

. Technically well-working, only three were built. Two of them are saved in working order at museums in Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

.

Hybrid power



Mixed power locomotives, utilising steam and diesel propulsion, have been produced in Russia, Britain and Italy.

Under severely unusual conditions (lack of coal, plenty of hydroelectricity) some locomotives in Switzerland were modified to use electricity to heat the boiler, making them electric-steam locomotive
Electric-steam locomotive
An electric-steam locomotive is a steam locomotive that uses electricity to heat the water in the boiler to create steam. This is a highly unusual type of locomotive that only makes economic sense under specific conditions. Normally it would be much more efficient to build and use an electric...

s.

Fireless locomotive





In a fireless locomotive the boiler is replaced by a steam accumulator
Steam accumulator
A Steam accumulator is an insulated steel pressure tank containing hot water and steam under pressure. It is a type of energy storage device. It can be used to smooth out peaks and troughs in demand for steam. Steam accumulators may take on a significance for energy storage in solar thermal...

 which is charged with steam (actually water at high temperature well above the boiling point, 212 °F/100 °C) from a stationary boiler. Fireless locomotives were used where there was a high fire risk (e.g., in oil refineries) or where cleanliness was important (e.g., in food factories). The water vessel ("boiler") is heavily insulated as is a fired locomotive. Until all the water has boiled away, the steam pressure does not drop except as the temperature drops.
Another class of fireless locomotive is a compressed air locomotive.

Steam-electric locomotive


A steam-electric locomotive is similar in concept to a diesel-electric locomotive, except that a steam engine is used to drive a generator instead of a diesel engine. Three such locomotives were built by the French engineer Jean Jacques Heilmann in the 1890s.

Most manufactured classes


The largest single class of steam locomotive in the world is the 0-10-0
0-10-0
Under the Whyte notation for the classification of steam locomotives, 0-10-0 represents the wheel arrangement of no leading wheels, ten powered and coupled driving wheels on five axles, and no trailing wheels...

 Russian / Soviet Class E steam locomoive with around 11,000 manufactured both in Russia and other countries such as Czechoslovakia, Germany, Sweden, Hungary and Poland. This class even far outnumbered the German DRB Class 52 2-10-0
2-10-0
Under the Whyte notation for the classification of steam locomotives, 2-10-0 represents the wheel arrangement of two leading wheels on one axle, ten powered and coupled driving wheels on five axles, and no trailing wheels...

 Kriegslok which consisted of approximate 7000 units.
The British LMS Stanier Class 5 4-6-0
LMS Stanier Class 5 4-6-0
The London Midland and Scottish Railway's Class 5 4-6-0, almost universally known as the Black Five, is a class of steam locomotive. It was introduced by William Stanier in 1934 and 842 were built between then and 1951...

 (Black Five) steam locomotive numbered 842 units. The DX class of the London and North Western Railway
London and North Western Railway
The London and North Western Railway was a British railway company between 1846 and 1922. It was created by the merger of three companies – the Grand Junction Railway, the London and Birmingham Railway and the Manchester and Birmingham Railway...

 numbered 943 units, including 86 engines built for the Lancashire and Yorkshire Railway
Lancashire and Yorkshire Railway
The Lancashire and Yorkshire Railway was a major British railway company before the 1923 Grouping. It was incorporated in 1847 from an amalgamation of several existing railways...

.

United States


Railroad locomotive engines in the United States have nearly always been built in and for United States railroads with very few imports, except in the earliest days. This is true because of the basic differences of markets in the United States which initially had many small markets located large distances apart; much different than Europe's much higher density markets. Locomotives that were cheap and rugged and could go over large distances over cheaply built and maintained tracks were the early requirements. Once the manufacture of engines was established on a wide scale there was very little advantage to buying an engine somewhere else that would have to be customized anyway to fit the local requirements and track conditions. Improvements in engine design of both European and U.S. origin could be and were incorporated by manufacturers when they could be justified in a generally very conservative and slow changing market. With the notable exception of the USRA standard
USRA standard
The USRA standard locomotives and railroad cars were designed by the United States Railroad Administration, the nationalised rail system of the United States during World War I. 1,856 steam locomotives and over 100,000 railroad cars were built to these designs during the USRA's tenure...

 locomotives, set during World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

, in the United States, steam locomotive manufacture was always semi-customised. Railroads ordered locomotives tailored to their specific requirements, though basic design features were always present. Railroads developed some specific characteristics; for example, the Pennsylvania Railroad
Pennsylvania Railroad
The Pennsylvania Railroad was an American Class I railroad, founded in 1846. Commonly referred to as the "Pennsy", the PRR was headquartered in Philadelphia, Pennsylvania....

 and the Great Northern had a preference for the Belpaire firebox
Belpaire firebox
The Belpaire firebox is a type of firebox used on steam locomotives. It was invented by Alfred Belpaire of Belgium. It has a greater surface area at the top of the firebox, improving heat transfer and steam production...

,. In the United States, large-scale manufacturers constructed locomotives for nearly all rail companies, although nearly all major railroads had shops capable of heavy repairs and some railroads (for example, the Norfolk and Western Railway
Norfolk and Western Railway
The Norfolk and Western Railway , a US class I railroad, was formed by more than 200 railroad mergers between 1838 and 1982. It had headquarters in Roanoke, Virginia for most of its 150 year existence....

 and the Pennsylvania Railroad, which had two erecting shops) constructed complete locomotives in their own shops. Companies manufacturing locomotives in the US included Baldwin Locomotive Works, American Locomotive Works (ALCO), Lima Locomotive Works, and others.

Steam locomotives required regular, and compared to a diesel-electric engine, frequent service and overhaul (often at government-regulated intervals in Europe and the U.S.) Many alterations and upgrades regularly occurred during overhauls. New appliances were added, unsatisfactory features removed, cylinders improved or replaced. Almost any part of the locomotive, including boilers were replaced or upgraded. When the service or upgrades got too expensive the locomotive was traded off or retired. On the Baltimore and Ohio Railroad
Baltimore and Ohio Railroad
The Baltimore and Ohio Railroad was one of the oldest railroads in the United States and the first common carrier railroad. It came into being mostly because the city of Baltimore wanted to compete with the newly constructed Erie Canal and another canal being proposed by Pennsylvania, which...

 two 2-10-2
2-10-2
Under the Whyte notation for the classification of steam locomotives, 2-10-2 represents the wheel arrangement of two leading wheels on one axle, usually in a leading truck, ten powered and coupled driving wheels on five axles, and two trailing wheels on one axle, usually in a trailing truck...

 locomotives were dismantled; the boilers were placed onto two new Class T 4-8-2
4-8-2
Under the Whyte notation for the classification of steam locomotives, 4-8-2 represents the wheel arrangement of four leading wheels on two axles , eight powered and coupled driving wheels on four axles, and two trailing wheels on one axle...

 locomotives and the residue wheel machinery made a pair of Class U 0-10-0
0-10-0
Under the Whyte notation for the classification of steam locomotives, 0-10-0 represents the wheel arrangement of no leading wheels, ten powered and coupled driving wheels on five axles, and no trailing wheels...

 switchers with new boilers. Union Pacific's fleet of 3-cylinder 4-10-2
4-10-2
Under the Whyte notation for the classification of steam locomotives, 4-10-2 represents the wheel arrangement of four leading wheels on two axles , ten powered and coupled driving wheels on five axles, and two trailing wheels on one axle...

 engines were converted into two-cylinder engines in 1942, because of high maintenance problems.

United Kingdom


Before the 1923 Grouping Act, the picture in the UK was mixed. The larger railway companies built locomotives in their own workshops but the smaller ones and industrial concerns ordered them from outside builders. A large market for outside builders was abroad because of the home-build policy exercised by the main railway companies. An example of a pre grouping works was the one at Melton Constable
Melton Constable
Melton Constable is a village and civil parish in the English county of Norfolk.It covers an area of and had a population of 518 in 225 households as of the 2001 census.For the purposes of local government, it falls within the district of North Norfolk...

 that maintained and built some of the locomotives for the Midland and Great Northern Joint Railway
Midland and Great Northern Joint Railway
The Midland and Great Northern Joint Railway, was a joint railway owned by the Midland Railway and the Great Northern Railway in eastern England, affectionately known as the 'Muddle and Get Nowhere' to generations of passengers, enthusiasts, and other users.The main line ran from Peterborough to...

. Other works included one at Boston (an early GNR building) and Horwich works.

Between 1923 and 1947, the "Big Four" railway companies (the Great Western Railway
Great Western Railway
The Great Western Railway was a British railway company that linked London with the south-west and west of England and most of Wales. It was founded in 1833, received its enabling Act of Parliament in 1835 and ran its first trains in 1838...

, the London, Midland and Scottish Railway
London, Midland and Scottish Railway
The London Midland and Scottish Railway was a British railway company. It was formed on 1 January 1923 under the Railways Act of 1921, which required the grouping of over 120 separate railway companies into just four...

, the London and North Eastern Railway
London and North Eastern Railway
The London and North Eastern Railway was the second-largest of the "Big Four" railway companies created by the Railways Act 1921 in Britain...

 and the Southern Railway) all built most of their own locomotives. Generally speaking, they only bought locomotives from outside builders when their own works were fully occupied (or as a result of government-mandated standardisation during wartime).

From 1948, British Railways allowed the former "Big Four" companies (now designated "Regions") to continue to build their own designs, but also created a range of standard locomotives which supposedly combined the best features from each region. Although a policy of "dieselisation
Dieselisation
Dieselisation or dieselization is a term generally used for the increasingly common use of diesel fuel in vehicles, as opposed to gasoline or steam engines.-Water Transport:...

" was adopted in 1955, BR continued to build new steam locomotives until 1960 (the last being named Evening Star).

Some independent manufacturers produced steam locomotives for a few more years, the last British-built industrial steam locomotive being constructed by Hunslet
Hunslet Engine Company
The Hunslet Engine Company is a British locomotive-building company founded in 1864 at Jack Lane, Hunslet, Leeds, West Yorkshire, England by John Towlerton Leather, a civil engineering contractor, who appointed James Campbell as his Works Manager.In 1871, James Campbell bought the company for...

 in 1971. Since then, a few specialised manufacturers have continued to produce small locomotives for narrow gauge and miniature railways, but as the prime market for these is the tourist and heritage railway
Heritage railway
thumb|right|the Historical [[Khyber train safari|Khyber Railway]] goes through the [[Khyber Pass]], [[Pakistan]]A heritage railway , preserved railway , tourist railway , or tourist railroad is a railway that is run as a tourist attraction, in some cases by volunteers, and...

 sector, the demand for such locomotives is limited. In November 2008, a new build main line steam locomotive, the 60163 Tornado
LNER Peppercorn Class A1 60163 Tornado
60163 Tornado is a main-line steam locomotive built in Darlington, England. Completed in 2008, Tornado was the first such locomotive built in the United Kingdom since Evening Star, the last steam locomotive built by British Railways, in 1960...

, was tested on UK mainlines for eventual charter and tour use.

Australia



In Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, Clyde Engineering
Clyde Engineering
Clyde Engineering was the name of part of the business now known as Downer EDI Rail. Clyde Engineering were involved in the construction of railway locomotives and rolling stock, as well as larger scale engineering projects on behalf of the governments of Australia...

 of Sydney
Sydney
Sydney is the most populous city in Australia and the state capital of New South Wales. Sydney is located on Australia's south-east coast of the Tasman Sea. As of June 2010, the greater metropolitan area had an approximate population of 4.6 million people...

 and also the Eveleigh
Eveleigh, New South Wales
Eveleigh is an inner-city suburb of Sydney, in the state of New South Wales, Australia. Eveleigh is located about 3 kilometres south of the Sydney central business district and is part of the local government area of the City of Sydney.- History :...

 Workshops built steam locomotives for the New South Wales Government Railways
New South Wales Government Railways
The New South Wales Government Railways was the government department that operated the New South Wales Government's railways until the establishment of the Public Transport Commission in 1972. Although later known officially as the Department of Railways, New South Wales, it was still generally...

. These include the C38 class 4-6-2; the first five were built at Clyde with streamlining
Streamliner
A streamliner is a vehicle incorporating streamlining in a shape providing reduced air resistance. The term is applied to high-speed railway trainsets of the 1930s to 1950s, and to their successor "bullet trains". Less commonly, the term is applied to fully faired recumbent bicycles...

, the other 25 locomotives were built at Eveleigh (13) in Sydney, and Cardiff Workshops (12) near Newcastle. In Queensland, steam locomotives were locally constructed by Walkers. Similarly the South Australian state government railways also manufactured steam locomotives locally at Islington in Adelaide. The Victorian Railways
Victorian Railways
The Victorian Railways operated railways in the Australian state of Victoria from 1859 to 1983. The first railways in Victoria were private companies, but when these companies failed or defaulted, the Victorian Railways was established to take over their operations...

 constructed most of their locomotives at their Newport Workshops and Bendigo
Bendigo Workshops
Bendigo Workshops is a railway workshop located in the provincial city of Bendigo, Victoria, Australia. They are located in the north of the city and occupies 10.3 hectare of land beside the junction of the Swan Hill and Echuca railway lines.-History:...

 while in the early days locomotives were built at the Phoenix Foundry
Phoenix Foundry
The Phoenix Foundry was a company that built steam locomotives and other industrial machinery in the city of Ballarat, Victoria, Australia. Over 30 years they built 352 locomotives for the Victorian Railways, of 38 different designs.-History:...

 in Ballarat
Ballarat, Victoria
Ballarat is a city in the state of Victoria, Australia, approximately west-north-west of the state capital Melbourne situated on the lower plains of the Great Dividing Range and the Yarrowee River catchment. It is the largest inland centre and third most populous city in the state and the fifth...

. Locomotives constructed at the Newport shops ranged from the nA class 2-6-2
2-6-2
Under the Whyte notation for the classification of steam locomotives, 2-6-2 represents the wheel arrangement of two leading wheels, six coupled driving wheels and two trailing wheels.Other equivalent classifications are:...

T built for the narrow gauge
Narrow gauge lines of the Victorian Railways
The former Victorian Railways, the state railway authority in Victoria, Australia built a number of experimental narrow gauge railway lines around the beginning of the 20th century. Although all were closed by the early 1960s, parts of two have been reopened as heritage railways.- Background :A...

, up to the H class 4-8-4, the largest conventional locomotive ever to operate in Australia, which weighed 260 tons. However, the title of largest locomotive in Australia goes to the 263-ton NSWGR AD60 class 4-8-4+4-8-4
4-8-4+4-8-4
A 4-8-4+4-8-4, in the Whyte notation for the classification of steam locomotives by wheel arrangement, is a Garratt articulated locomotive. The wheel arrangement is effectively two 4-8-4 locomotives operating back to back....

 Garratt
Garratt
A Garratt is a type of steam locomotive that is articulated in three parts. Its boiler is mounted on the centre frame, and two steam engines are mounted on separate frames, one on each end of the boiler. Articulation permits larger locomotives to negotiate curves and lighter rails that might...

 (Oberg:1975), which were built by Beyer-Peacock
Beyer-Peacock
Beyer, Peacock and Company was an English railway Locomotive manufacturer with a factory in Gorton, Manchester. Founded by Charles Beyer and Richard Peacock, it traded from 1854 until 1966...

 in the United Kingdom.

Sweden


In the 19th and early 20th centuries, most Swedish steam locomotives were manufactured in England. But later on, most steam locomotives were built by local factories including NOHAB in Trollhättan
Trollhättan
Trollhättan is a city and the seat of Trollhättan Municipality, Västra Götaland County, Sweden with 44,498 inhabitants in 2005. It is located 75 km north of Sweden's second-largest city, Gothenburg....

 and ASJ in Falun
Falun
Falun is a city and the seat of Falun Municipality in Dalarna County, Sweden, with 36,447 inhabitants in 2005. It is also the capital of Dalarna County...

. One of the most successful types was the class "B" (4-6-0
4-6-0
Under the Whyte notation for the classification of steam locomotives, 4-6-0 represents the wheel arrangement of four leading wheels on two axles in a leading truck, six powered and coupled driving wheels on three axles, and no trailing wheels. This wheel arrangement became the second-most popular...

), inspired by the Prussian class P8. Many of the Swedish steam locomotives were preserved during the Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

 in case of war. During the 1990s, these steam locomotives were sold to non-profit associations or abroad, which is why the Swedish class B, class S (2-6-4
2-6-4
Under the Whyte notation for the classification of steam locomotives, a 2-6-4 locomotive has two leading wheels, six coupled driving wheels and four trailing wheels...

) and class E2 (2-8-0
2-8-0
Under the Whyte notation for the classification of steam locomotives, 2-8-0 represents the wheel arrangement of two leading wheels on one axle , eight powered and coupled driving wheels on four axles, and no trailing wheels...

) locomotives can now be seen in England, the Netherlands, Germany and Canada.

Categorisation


Steam locomotives are categorised by their wheel arrangement. The two dominant systems for this are the Whyte notation
Whyte notation
The Whyte notation for classifying steam locomotives by wheel arrangement was devised by Frederick Methvan Whyte and came into use in the early twentieth century encouraged by an editorial in American Engineer and Railroad Journal...

 and UIC classification
UIC classification
The UIC classification of locomotive axle arrangements describes the wheel arrangement of locomotives, multiple units and trams. It is set out in the International Union of Railways "Leaflet 650 - Standard designation of axle arrangement on locomotives and multiple-unit sets". It is used in much...

.

The Whyte notation, used in most English speaking and Commonwealth
Commonwealth of Nations
The Commonwealth of Nations, normally referred to as the Commonwealth and formerly known as the British Commonwealth, is an intergovernmental organisation of fifty-four independent member states...

 countries, represents each set of wheels with a number. Different arrangements were given names which usually reflect the first usage of the arrangement; for instance the "Santa Fe" type (2-10-2
2-10-2
Under the Whyte notation for the classification of steam locomotives, 2-10-2 represents the wheel arrangement of two leading wheels on one axle, usually in a leading truck, ten powered and coupled driving wheels on five axles, and two trailing wheels on one axle, usually in a trailing truck...

) is so called because the first examples were built for the Atchison, Topeka and Santa Fe Railway
Atchison, Topeka and Santa Fe Railway
The Atchison, Topeka and Santa Fe Railway , often abbreviated as Santa Fe, was one of the larger railroads in the United States. The company was first chartered in February 1859...

. These names were informally given and varied according to region and even politics.

The UIC classification is used mostly in European countries apart from the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

. It designates consecutive pairs of wheels (informally "axles") with a number for non-driving wheels and a capital letter for driving wheels (A=1, B=2, etc.) So a Whyte 4-6-2 designation would be an equivalent to a 2-C-1 UIC designation.

On many railroads, locomotives were organised into class
Class (locomotive)
Class refers to a group of locomotives built to a common design for a single railroad. Often members of a particular class had detail variations between individual examples, and these could lead to subclasses. Sometimes technical alterations move a locomotive from one class to another...

es. These broadly represented locomotives which could be substituted for each other in service, but most commonly a class represented a single design. As a rule classes were assigned some sort of code, generally based on the wheel arrangement. Classes also commonly acquired nicknames, such as 'Pugs', representing notable (and sometimes uncomplimentary) features of the locomotives.

Measurement


In the steam locomotive era, two measures of locomotive performance were generally applied. At first, locomotives were rated by tractive effort
Tractive effort
As used in mechanical engineering, the term tractive force is the pulling or pushing force exerted by a vehicle on another vehicle or object. The term tractive effort is synonymous with tractive force, and is often used in railway engineering to describe the pulling or pushing capability of a...

 This can be roughly calculated by multiplying the total piston area by 85% of the boiler pressure (a rule of thumb reflecting the slightly lower pressure in the steam chest above the cylinder) and dividing by the ratio of the driver diameter over the piston stroke. However, the precise formula is:

Tractive Effort is defined as the average force developed during one revolution of the driving wheels at the rail head. This is expressed as:
.

where d is bore of cylinder (diameter) in inches,
s is cylinder stroke, in inches,
P is boiler pressure in pound per square inch,
D is driving wheel diameter in inches,
c is a factor that depends on the effective cut-off
Cutoff (steam engine)
In a steam engine, cutoff is the point in the piston stroke at which the inlet valve is closed. On a steam locomotive, the cutoff is controlled by the reverser....

. In the U.S. "c" is usually set at 0.85, but lower on engines that have maximum cutoff limited to 50-75%.

It is critical to appreciate the use of the term 'average', as not all effort is constant during the one revolution of the drivers for at some points of the cycle only one piston is exerting turning moment and at other points both pistons are working. Not all boilers deliver full power at starting and also the tractive effort decreases as the rotating speed increases.

Tractive effort is a measure of the heaviest load a locomotive can start or haul at very low speed over the ruling grade in a given territory.

However, as the pressure grew to run faster freight and heavier passenger trains, tractive effort was seen to be an inadequate measure of performance because it did not take into account speed.

Therefore in the 20th century, locomotives began to be rated by power output. A variety of calculations and formulas were applied, but in general railroads used dynamometer car
Dynamometer car
A dynamometer car is a railroad maintenance of way car used for measuring various aspects of a locomotive's performance. Measurements include tractive effort , power, top speed, etc.-History:...

s to measure tractive force at speed in actual road testing.

British railway companies have been reluctant to disclose figures for drawbar horsepower and have usually relied on continuous tractive effort instead.

Relation to wheel arrangement


Whyte classification is connected to locomotive performance, but through a somewhat circuitous path. Given adequate proportions of the rest of the locomotive, power output is determined by the size of the fire, and for a bituminous coal-fuelled locomotive, this is determined by the grate area. Modern non-compound locomotives are typically able to produce about 40 drawbar horsepower per square foot of grate. Tractive force, as noted earlier, is largely determined by the boiler pressure, the cylinder proportions, and the size of the driving wheels. However, it is also limited by the weight on the driving wheels (termed "adhesive weight"), which needs to be at least four times the tractive effort.

The weight of the locomotive is roughly proportional to the power output; the number of axles required is determined by this weight divided by the axleload limit for the trackage where the locomotive is to be used. The number of driving wheels is derived from the adhesive weight in the same manner, leaving the remaining axles to be accounted for by the leading and trailing bogies. Passenger locomotives conventionally had two-axle leading bogies for better guidance at speed; on the other hand, the vast increase in the size of the grate and firebox in the 20th century meant that a trailing bogie was called upon to provide support. On the European continent, some use was made of several variants of the Bissel bogie
Bissel bogie
A Bissel truck is a very simple and commonly used way of designing a carrying axle on a steam locomotive to enable it to negotiate curves more easily. The design uses a single-axled bogie, usually known as a pony truck, whose pivot is towards the centre of the locomotive...

in which the swivelling movement of a single axle truck controls the lateral displacement of the front driving axle (and in one case the second axle too). This was mostly applied to 8-coupled express and mixed traffic locomotives and considerably improved their ability to negotiate curves whilst restricting overall locomotive wheelbase and maximising adhesion weight.

As a rule, "shunting engines" (US "switching engines") omitted leading and trailing bogies, both to maximise tractive effort available and to reduce wheelbase. Speed was unimportant; making the smallest engine (and therefore smallest fuel consumption) for the tractive effort paramount. Driving wheels were small and usually supported the firebox as well as the main section of the boiler. Banking engines
Bank engine
A bank engine or helper engine or pusher engine is a railway locomotive that temporarily assists a train that requires additional power or traction to climb a grade...

 (US "helper engines") tended to follow the principles of shunting engines, except that the wheelbase limitation did not apply, so banking engines tended to have more driving wheels. In the U.S., this process eventually resulted in the Mallet
Mallet locomotive
The Mallet Locomotive is a type of articulated locomotive, invented by a Swiss engineer named Anatole Mallet ....

 type with its many driven wheels, and these tended to acquire leading and then trailing bogies as guidance of the engine became more of an issue.

As locomotive types began to diverge in the late 19th century, freight engine designs at first emphasised tractive effort, whereas those for passenger engines emphasised speed. Over time, freight locomotive size increased, and the overall number of axles increased accordingly; the leading bogie was usually a single axle, but a trailing truck was added to larger locomotives to support a larger firebox that could no longer fit between or above the driving wheels. Passenger locomotives had leading bogies with two axles, fewer driving axles, and very large driving wheels in order to limit the speed at which the reciprocating parts had to move.

In the 1920s the focus in the United States turned to horsepower, epitomised by the "super power" concept promoted by the Lima Locomotive Works
Lima Locomotive Works
Lima Locomotive Works was an American firm that manufactured railroad locomotives from the 1870s through the 1950s. The company took the most distinctive part of its name from its main shops location in Lima, Ohio. The shops were located between the Baltimore & Ohio's Cincinnati-Toledo main line...

, although tractive effort was still the prime consideration after World War I to the end of steam. Freight trains were to run faster; passenger locomotives needed to pull heavier loads at speed. In essence, the size of grate and firebox increased without changes to the remainder of the locomotive, requiring the addition of a second axle to the trailing truck. Freight 2-8-2
2-8-2
Under the Whyte notation for the classification of steam locomotives, 2-8-2 represents the wheel arrangement of two leading wheels on one axle , eight powered and coupled driving wheels on four axles, and two trailing wheels on one axle...

s became 2-8-4
2-8-4
In the Whyte notation, a 2-8-4 is a railroad steam locomotive that has one unpowered leading axle followed by four powered driving axles and two unpowered trailing axles. This locomotive type is most often referred to as a Berkshire, though the Chesapeake and Ohio Railway used the name Kanawha for...

s while 2-10-2
2-10-2
Under the Whyte notation for the classification of steam locomotives, 2-10-2 represents the wheel arrangement of two leading wheels on one axle, usually in a leading truck, ten powered and coupled driving wheels on five axles, and two trailing wheels on one axle, usually in a trailing truck...

s became 2-10-4
2-10-4
Under the Whyte notation for the classification of steam locomotives, a 2-10-4 locomotive has two leading wheels, ten driving wheels , and four trailing wheels...

s. Similarly, passenger 4-6-2
4-6-2
4-6-2, in the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels on two axles , six powered and coupled driving wheels on three axles, and two trailing wheels on one axle .These locomotives are also known as Pacifics...

s became 4-6-4
4-6-4
Under the Whyte notation for the classification of steam locomotives, 4-6-4 represents the wheel arrangement of four leading wheels on two axles , six powered and coupled driving wheels on three axles, and four trailing wheels on two axles .Other equivalent classifications are:UIC classification:...

s. In the United States this led to a convergence on the dual-purpose 4-8-4
4-8-4
Under the Whyte notation classification of steam locomotives, 4-8-4 represents the wheel arrangement of four leading wheels on two axles , eight powered and coupled driving wheels on four axles, and four trailing wheels on two axles .Other equivalent classifications are:UIC classification: 2D2...

 and the 4-6-6-4 articulated configuration, which was used for both freight and passenger service. Mallet locomotives went through a similar transformation and evolved from bank engines into huge mainline locomotives with gargantuan fireboxes; their driving wheels being increased in size in order to allow faster running.

The end of steam in general use


The introduction of electric
Electric locomotive
An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or an on-board energy storage device...

 locomotives at the turn of the 20th century and later diesel-electric locomotives spelled the beginning of the end for steam locomotives, although that end was long in coming. As Diesel power, more especially with electric transmission, became more reliable in the 1930s it gained a foothold in North America. The full changeover took place there during the 1950s. In continental Europe large-scale electrification had displaced steam power by the 1970s. Steam had in its favour familiar technology, adapted well to local facilities and consumed a wide variety of fuels; this led to its continued use in many countries to the end of the 20th Century. They have considerably less thermal efficiency than modern diesels, requiring constant maintenance and labour to keep them operational. Water is required at many points throughout a rail network and becomes a major problem in desert areas, as are found in some regions within the United States, Australia and South Africa. In other localities the local water is unsuitable. The reciprocating mechanism on the driving wheels of a two-cylinder single expansion steam locomotive tended to pound the rails (see "hammer blow
Hammer blow
Hammer blow, in rail terminology, refers to the vertical forces transferred to the track by the driving wheels of a steam locomotive and some diesel locomotives. The largest proportion of this is due to the unbalanced reciprocating motion, although the piston thrusts also contribute a portion to it...

"), thus requiring more maintenance. Raising steam from coal took a matter of hours which brought serious pollution problems. Coal-burning locomotives required fire cleaning and ash removal between turns of duty. This was all done in the open air by hand in deplorable working conditions. Diesel or electric locomotives, by comparison, drew benefit from new custom built servicing facilities. Finally, the smoke from steam locomotives was deemed objectionable; in fact, the first electric and diesel locomotives were developed to meet smoke abatement requirements although this did not take into account the high level of invisible pollution in diesel exhaust smoke especially when idling. It should also be remembered that the power for electric trains is, for the most part, derived from steam generated in a power station — often fuelled with coal.

U.S. decline



Mainline diesel-electric locomotives first appeared on the Baltimore and Ohio Railroad
Baltimore and Ohio Railroad
The Baltimore and Ohio Railroad was one of the oldest railroads in the United States and the first common carrier railroad. It came into being mostly because the city of Baltimore wanted to compete with the newly constructed Erie Canal and another canal being proposed by Pennsylvania, which...

, in 1935 as locomotive No. 50. The diesel reduced maintenance costs dramatically, while increasing locomotive availability. On the Chicago, Rock Island and Pacific Railroad
Chicago, Rock Island and Pacific Railroad
The Chicago, Rock Island and Pacific Railroad was a Class I railroad in the United States. It was also known as the Rock Island Line, or, in its final years, The Rock.-Incorporation:...

 the new units delivered over 350000 miles (563,269 km) a year, compared with about 120,000–150,000 for a mainline steam locomotive. World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 delayed dieselisation
Dieselisation
Dieselisation or dieselization is a term generally used for the increasingly common use of diesel fuel in vehicles, as opposed to gasoline or steam engines.-Water Transport:...

 in the U.S., but the pace picked up in the 1950s. 1960 is normally considered the last year for regular class 1 Main Line standard gauge steam operations in the United States, with operations on the Grand Trunk Western, Illinois Central, Norfolk and Western, and Duluth Missabe and Iron Range Railroads (Stagner,1991 National Ry. Bul. Vol.56 #4), as well as Canadian Pacific operations in the state of Maine (Holland, 2006 Canadian Pacific Steam Vol. 1).

However, the Grand Trunk Western used some steam on regular passenger trains into 1961, the last occurring unannounced on trains 56 and 21 in the Detroit area on September 20, 1961 with 4-8-4 6323, one day before its flue time expired (Stagner, 1991; Pinkepank,2003 Grand Trunk Western Vol. 1). The last standard gauge regular freight service steam by a class 1 railroad was on the isolated Leadville branch of the Colorado and Southern (Burlington Lines) October 11, 1962 with 2-8-0 641(Stagner, 1991). Narrow gauge steam was used for freight service by the Denver and Rio Grande Western on the 250 miles (402.3 km) run from Alamosa, Colorado to Farmington, New Mexico via Durango until service ceased December 5, 1968 (Stagner, 1991). The Union Pacific is the only Class I railroad in the U.S. to have never completely dieselized. It has always had at least one operational steam locomotive, Union Pacific 844
Union Pacific 844
Union Pacific 844 is a 4-8-4 steam locomotive owned by Union Pacific Railroad. It was the last steam locomotive delivered to Union Pacific and is unique in that it is the only steam locomotive never retired by a North American Class I railroad....

, on its roster. Some U.S. shortlines continued steam operations into the 1960s, and the Northwestern Steel and Wire
Northwestern Steel and Wire
Northwestern Steel and Wire was a steel mill and wire factory located in Sterling, Illinois. It began producing steel in 1936 and ceased production in 2001.-Early history:...

 mill in Sterling, IL, continued to operate steam locomotives until December 1980. The Silverton branch of the Denver and Rio Grande Western, which in 1981 became the Durango and Silverton Narrow Gauge Railroad
Durango and Silverton Narrow Gauge Railroad
The Durango and Silverton Narrow Gauge Railroad is a narrow gauge heritage railroad that operates of track between Durango and Silverton, in the US state of Colorado...

, continues to use steam locomotives, as it has since construction in 1882.

British decline



Trials of diesel locomotives and railcar
Railcar
A railcar, in British English and Australian English, is a self-propelled railway vehicle designed to transport passengers. The term "railcar" is usually used in reference to a train consisting of a single coach , with a driver's cab at one or both ends. Some railways, e.g., the Great Western...

s began in Britain in the 1930s but made only limited progress. One problem was that British diesel locomotives were often seriously under-powered, compared with the steam locomotives against which they were competing.

After 1945, problems associated with post-war reconstruction and the availability of cheap domestic-produced coal kept steam in widespread use throughout the two following decades. However the ready availability of cheap oil led to new dieselisation programmes from 1955 and these began to take full effect from around 1962. Towards the end of the steam era, steam motive power was allowed to fall into a dire state of repair. The last steam-hauled service trains on the British Railways network ran in 1968, but the use of steam locomotives in British industry
Industrial railway
An industrial railway is a type of railway that is not available for public transportation and is used exclusively to serve a particular industrial, logistics or military site...

 continued into the 1980s. In June 1975 there were still 41 locations where steam was in regular use, and many more where engines were held in reserve in case of diesel failures. Gradually, the decline of the ironstone quarries, steel, coal mining and shipbuilding industries – and the plentiful supply of redundant British Rail diesel shunters as replacements – led to the disappearance of steam power for commercial uses.

Several hundred rebuilt and preserved steam locomotives are still used on preserved volunteer-run 'heritage' railway
Heritage railway
thumb|right|the Historical [[Khyber train safari|Khyber Railway]] goes through the [[Khyber Pass]], [[Pakistan]]A heritage railway , preserved railway , tourist railway , or tourist railroad is a railway that is run as a tourist attraction, in some cases by volunteers, and...

 lines in the UK. A proportion of the locomotives are regularly used on the national rail network by private operators where they run special excursions and touring trains. New steam locomotives, such as the LNER Peppercorn Class A1 60163 Tornado
LNER Peppercorn Class A1 60163 Tornado
60163 Tornado is a main-line steam locomotive built in Darlington, England. Completed in 2008, Tornado was the first such locomotive built in the United Kingdom since Evening Star, the last steam locomotive built by British Railways, in 1960...

 have been built or are in the planning stage.

Russia


In the USSR, although the first mainline diesel-electric locomotive was built in USSR in 1924, the last steam locomotive (model П36, serial number 251) was built in 1956; it is now in the Museum of Railway Machinery at former Warsaw Rail Terminal, Saint Petersburg
Saint Petersburg
Saint Petersburg is a city and a federal subject of Russia located on the Neva River at the head of the Gulf of Finland on the Baltic Sea...

. In the European part of the USSR, almost all steam locomotives were replaced by diesel and electric locomotives in the 1960s; in Siberia
Siberia
Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...

 with its cheap coal, steam locomotives were in active use till the mid-1970s. However, some photographs exist of Russian steam locomotives at work into the 1980s, and many accurate historical records state that Russian Decapods, L-class 2-10-0
2-10-0
Under the Whyte notation for the classification of steam locomotives, 2-10-0 represents the wheel arrangement of two leading wheels on one axle, ten powered and coupled driving wheels on five axles, and no trailing wheels...

s, and LV-class 2-10-2
2-10-2
Under the Whyte notation for the classification of steam locomotives, 2-10-2 represents the wheel arrangement of two leading wheels on one axle, usually in a leading truck, ten powered and coupled driving wheels on five axles, and two trailing wheels on one axle, usually in a trailing truck...

s were not retired until 1980-1985. Until 1994, Russia had at least 1,000 steam locomotives stored in operable condition in case of "national emergencies".

South Africa


In South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

, the last new locomotives purchased were 2-6-2+2-6-2 Garretts from Hunslet Taylor for the 2 feet (609.6 mm) gauge lines in 1968 (Durrant, Jorgensen, Lewis, 1972 Steam on the Veld, Pg. 61). Locomotive engineer L. D. Porta's
Livio Dante Porta
Livio Dante Porta was an Argentine steam locomotive engineer. He is particularly remembered for his innovative modifications to existing locomotive systems in order to obtain higher performance, energy efficiency and reduced pollution. He developed the Kylpor and Lempor exhaust systems...

 designs appeared on a Class 19D engine in 1979, then a former Class 25 4-8-4 engine, became a Class 26, termed the "Red Devil" No. 3450, which demonstrated an improved overall performance with decreased coal and water consumption. The single class 26 locomotive operated until the end of steam.

Another class 25NC locomotive, No. 3454, nicknamed the "Blue Devil" because of its colour scheme, received modifications including a most obvious set of double side-by-side exhaust stacks. In southern Natal, two former South African Railway gauge NGG16 Garratts operating on the privatised Port Shepstone and Alfred County Railway (ACR) received some L. D. Porta modifications in 1990 becoming a new NGG16A class.

By 1994 almost all commercial steam locomotives were put out of service, although many of them are preserved in museums or at railway stations for public viewing. Today only a few privately owned steam locomotives are still operating in South Africa, namely the ones being used by the 5-star luxury train Rovos Rail
Rovos Rail
Rovos Rail is a private railway company operating out of Capital Park Station in Pretoria, South Africa. The Society of International Railway Travelers has regularly named the Pride of Africa, as the train is called, as one of the World's Top 25 Trains because of its excellent accommodation, public...

, and the tourist trains Outeniqua Tjoe Choo, Apple Express and (until 2008) Banana Express.

China


China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 continued to build mainline steam locomotives until late in the century, even building a few examples for American tourist operations. China was the last main-line user of steam locomotives, such use ending officially on the Ji-Tong line at the end of 2005. Some steam locomotives are still (2011) in use in industrial operations in China. Some coal and other mineral operations maintain an active roster of JS, SY, or QJ
China Railways QJ
The QJ was a type of heavy freight steam locomotive used by China Railways. The majority were made by Datong locomotive factory...

 steam locomotives bought secondhand from China Rail. The last steam locomotive built in China was 2-8-2 SY 1772, finished in 1999. As of 2008, at least five Chinese steam locomotives exist in the United States – 3 QJ's bought by RDC (2 for IAIS
Iais
Iais is a genus of isopod crustaceans. Iais species are found in association with larger isopods of the family Sphaeromatidae, usually on the ventral surface of the larger animal, between the pereiopods and on the pleopods. They are native to Australasia and South America, although Iais californica...

 and 1 for R.J. Corman), a JS bought by the Boone Scenic Railway, and an SY bought by the NYSW for tourist operations, but re-painted and modified to represent a 1920s era U.S. locomotive.

South Korea


The first steam locomotive in South Korea was the Moga (Mogul), which first ran on September 9, 1899 (Gyeong-In Line) 2-6-0
2-6-0
Under the Whyte notation for the classification of steam locomotives, 2-6-0 represents the wheel arrangement of two leading wheels on one axle, usually in a leading truck, six powered and coupled driving wheels on three axles, and no trailing wheels. This arrangement is commonly called a Mogul...

, followed by Sata, Pureo, Ame, Sig, Mika (USRA Heavy Mikado
USRA Heavy Mikado
The USRA Heavy Mikado was a USRA standard class of steam locomotive designed under the control of the United States Railroad Administration, the nationalized railroad system in the United States during World War I. These locomotives were of 2-8-2 wheel arrangement in the Whyte notation, or 1′D1′...

), Pasi (USRA Light Pacific
USRA Light Pacific
The USRA Light Pacific was a USRA standard class of steam locomotive designed under the control of the United States Railroad Administration, the nationalized railroad system in the United States during World War I...

), Hyeogi (Narrow gauge), Class 901, Mateo, Sori and Tou. Used until 1967, the Moga is now in the Railroad Museum.

Other countries


In other countries, the dates for conversion from steam varied.

On the contiguous North American standard gauge network including Canada, Mexico, and the United States, standard gauge main line steam with 1946-built 4-8-4's handling freight between Mexico City and Irapuato lasted until 1968 (Eagleson, Ziel, 1973 The Twilight of World Steam). The Mexican Pacific, a standard gauge short line in the state of Sinaloa, was reported in August 1987 (World Steam Magazine #101) to still be using steam, with a roster of one 4-6-0, two 2-6-2's and one 2-8-2.

By March 1973 in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, steam had vanished in all states. Diesel locomotives were more efficient and the demand for manual labour for service and repairs was less than steam. Cheap oil had cost advantages over coal.

In Finland
Finland
Finland , officially the Republic of Finland, is a Nordic country situated in the Fennoscandian region of Northern Europe. It is bordered by Sweden in the west, Norway in the north and Russia in the east, while Estonia lies to its south across the Gulf of Finland.Around 5.4 million people reside...

, the first diesels were introduced in the mid-1950s and they superseded the steam locomotives during the early '60s. The State Railways (VR
VR Group
VR or VR Group is a state-owned railway company in Finland. Formerly known as Suomen Valtion Rautatiet until 1922 and Valtionrautatiet / Statsjärnvägarna until 1995...

) operated steam locomotives until 1975.

In Poland
Poland
Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...

, on non-electrified tracks steam locomotives were superseded almost entirely by diesels by the early '90s. A few steam locomotives, however, operate still from Wolsztyn
Wolsztyn
Wolsztyn is a town in western Poland, on the western edge of Greater Poland Voivodeship...

. Although they are maintained operational rather as a means of preserving railway heritage and as a tourist attraction, they do haul regular scheduled trains (mostly to Poznań
Poznan
Poznań is a city on the Warta river in west-central Poland, with a population of 556,022 in June 2009. It is among the oldest cities in Poland, and was one of the most important centres in the early Polish state, whose first rulers were buried at Poznań's cathedral. It is sometimes claimed to be...

). Apart from that, numerous railway museums and heritage railways (mostly narrow gauge
Narrow gauge
A narrow gauge railway is a railway that has a track gauge narrower than the of standard gauge railways. Most existing narrow gauge railways have gauges of between and .- Overview :...

) own steam locomotives in working condition.

In Germany, steam locomotives continue to be used on a daily all-year-round basis on several narrow gauge passenger railways. The largest of these is the Harzer Schmalspur Bahnen network in the Harz Mountains, with dozens of daily trains on several routes.

In France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

, steam locomotives have not been used for commercial services since 24 September 1975.

In Bosnia and Herzegovina
Bosnia and Herzegovina
Bosnia and Herzegovina , sometimes called Bosnia-Herzegovina or simply Bosnia, is a country in Southern Europe, on the Balkan Peninsula. Bordered by Croatia to the north, west and south, Serbia to the east, and Montenegro to the southeast, Bosnia and Herzegovina is almost landlocked, except for the...

, some steam locomotives are still used for industrial purposes, for example at coal mineyard in Banovići
Banovici
Banovići is a town and municipality in northeastern Bosnia and Herzegovina. The intensive development of Banovići begins with construction of the railway Brčko-Banovići in the year 1946. Due to its quality, brown coal from Banovići is well-known all over Europe.-Geography:Banovići Municipality is...

 and ArcelorMittal factory in Zenica
Zenica
Zenica is an industrial city in Bosnia and Herzegovina. It is the capital of the Zenica-Doboj Canton of the Federation of Bosnia and Herzegovina entity...

.

In India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

, steam locomotives were built as late as 1972 and in use until 2000; they were replaced by a combination of diesel and electric locomotives. A steam locomotive celebration run was organised between Thane
Thane
Thane , is a city in Maharashtra, India, part of the Mumbai Metropolitan Region, northeastern suburb of Mumbai at the head of the Thane Creek. It is the administrative headquarters of Thane district. On 16 April 1853, G.I.P...

 and Mumbai
Mumbai
Mumbai , formerly known as Bombay in English, is the capital of the Indian state of Maharashtra. It is the most populous city in India, and the fourth most populous city in the world, with a total metropolitan area population of approximately 20.5 million...

 to commemorate the 150th year of railways in India.

In Sri Lanka
Sri Lanka
Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...

, one steam locomotive is maintained for private service to power the Viceroy Special
Viceroy Special
The Viceroy Special is a special passenger train service operated by J.F. Tours & Travels Ltd. Powered by the sole steam locomotive kept in operation in Sri Lanka, it is operated as a private train on all railway lines in the island...

.


Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

 also has experience with steam locomotives since 1876. New E10 0-10-0 tank locomotives were purchased as late as 1967 (Kautzor, 2010). The last locomotives – manufactured by Krupp
Krupp
The Krupp family , a prominent 400-year-old German dynasty from Essen, have become famous for their steel production and for their manufacture of ammunition and armaments. The family business, known as Friedrich Krupp AG Hoesch-Krupp, was the largest company in Europe at the beginning of the 20th...

, Germany, D Series, in 1954 – operated until 1994. In 1994 they were replaced by diesel locomotives. In Sumatra Barat (West Sumatra
West Sumatra
West Sumatra is a province of Indonesia. It lies on the west coast of the island Sumatra. It borders the provinces of North Sumatra to the north, Riau and Jambi to the east, and Bengkulu to the southeast. It includes the Mentawai Islands off the coast...

) and Ambarawa
Ambarawa
Ambarawa is a market town located between Semarang and Salatiga in Central Java, Indonesia.Ambarawa was an important connecting rail link providing a cog railway connecting through Central Java as far as Yogyakarta via Magelang. The Semarang-Ambarawa-Magelang line was fully operational until 1977...

 we can find the rack railway
Rack railway
A rack-and-pinion railway is a railway with a toothed rack rail, usually between the running rails. The trains are fitted with one or more cog wheels or pinions that mesh with this rack rail...

 track train (with maximum elevated 6% in mountainous area), now operated for tourism only. There are two museums, Taman Mini and Ambarawa
Ambarawa
Ambarawa is a market town located between Semarang and Salatiga in Central Java, Indonesia.Ambarawa was an important connecting rail link providing a cog railway connecting through Central Java as far as Yogyakarta via Magelang. The Semarang-Ambarawa-Magelang line was fully operational until 1977...

 (Ambarawa Railway Museum
Ambarawa Railway Museum
The Ambarawa Railway Museum, is a museum located in Ambarawa in Central Java, Indonesia. The museum focuses on the collection of steam locomotives, the remains of the closing of the 3 ft 6in railway line.-Museum building and location:...

).

Pakistan
Pakistan Railways
This article is about the rail company in Pakistan. For technical details and operations see: Transport in Pakistan.Pakistan Railways is a national state-owned rail transport service of Pakistan, head-quartered in Lahore. It is administered by the federal government under the Ministry of Railways....

 still has a regular steam locomotive service; a line operates in the North-West Frontier Province
North-West Frontier Province
Khyber Pakhtunkhwa , formerly known as the North-West Frontier Province and various other names, is one of the four provinces of Pakistan, located in the north-west of the country...

 and Sindh; It has been preserved as a "nostalgia" service for tourism in exotic locales, indeed it is specifically advertised as being for "steam buffs".

Hopes of revival


Dramatic increases in the cost of diesel fuel prompted several initiatives to revive steam power. However none of these has progressed to the point of production and, in the early 21st century, steam locomotives operate only in a few isolated regions of the world and in tourist operations
Heritage railway
thumb|right|the Historical [[Khyber train safari|Khyber Railway]] goes through the [[Khyber Pass]], [[Pakistan]]A heritage railway , preserved railway , tourist railway , or tourist railroad is a railway that is run as a tourist attraction, in some cases by volunteers, and...

.
In Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

, a small number of fireless steam locomotives
Fireless locomotive
A fireless locomotive is a type of locomotive designed for use under conditions restricted by either the presence of flammable material or the need for cleanliness...

 are still working in industrial service, e.g. at power stations, where an on-site supply of steam is readily available.

The Swiss company Dampflokomotiv- und Maschinenfabrik DLM AG delivered eight steam locomotives to rack railway
Rack railway
A rack-and-pinion railway is a railway with a toothed rack rail, usually between the running rails. The trains are fitted with one or more cog wheels or pinions that mesh with this rack rail...

s in Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

 and Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...

 between 1992 and 1996. Four of them are now the main means of traction on the Brienz Rothorn Bahn
Brienz Rothorn Bahn
The Brienz Rothorn Bahn is an gauge tourist rack railway in Switzerland, which climbs from Brienz, at the eastern end of Lake Brienz, to the summit of the Brienzer Rothorn mountain...

; the four others were for the Schafbergbahn
Schafbergbahn
The Schafberg Railway is a metre gauge cog railway in Upper Austria leading from Sankt Wolfgang im Salzkammergut up to the Schafberg . With a total length of 5.85 km it gains about 1,200 m in height difference. The rail gauge is . It uses the Abt system. Operation started in 1893...

 in Austria, where they run 90% of the trains.

The same company rebuilt a German 2-10-0 locomotive to new standards with modifications such as roller bearings, light oil firing and boiler insulation.

Several heritage railways in the UK have built new steam locomotives in the 1990s and early 21st century. These include the narrow gauge Ffestiniog
Ffestiniog Railway
The Ffestiniog Railway is a narrow gauge heritage railway, located in Gwynedd, Wales. It is a major tourist attraction located mainly within the Snowdonia National Park....

 and Corris
Corris Railway
The Corris Railway is a narrow gauge preserved railway based in Corris on the border between Merionethshire and Montgomeryshire in Mid-Wales....

 railways in Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...

. The Hunslet Engine Company
Hunslet Engine Company
The Hunslet Engine Company is a British locomotive-building company founded in 1864 at Jack Lane, Hunslet, Leeds, West Yorkshire, England by John Towlerton Leather, a civil engineering contractor, who appointed James Campbell as his Works Manager.In 1871, James Campbell bought the company for...

 was revived in 2005 and is now building steam locomotives on a commercial basis. A standard gauge LNER Peppercorn Pacific
LNER Peppercorn Class A1
The London and North Eastern Railway Peppercorn Class A1 is a type of express passenger steam locomotive. Forty-nine original Peppercorn Class A1s were built to the design of Arthur Peppercorn during the early British Railways era, but all were scrapped with the discontinuation of steam,...

 "Tornado
LNER Peppercorn Class A1 60163 Tornado
60163 Tornado is a main-line steam locomotive built in Darlington, England. Completed in 2008, Tornado was the first such locomotive built in the United Kingdom since Evening Star, the last steam locomotive built by British Railways, in 1960...

" was completed at Hopetown Works
Hopetown Carriage Works
Hopetown Carriage Works, built in 1853 by Joseph Sparkes in Darlington, County Durham), England, was a workshop of the world's first publicly subscribed passenger railway, the 1825-63 Stockton and Darlington Railway, and also of the subsequent railway companies into which the SD&R was absorbed....

, Darlington
Darlington Works
Darlington railway works, known in the town as North Road Shops, was built in 1863 by the Stockton and Darlington Railway in the town of Darlington in the north east of England.-NER History:The first new locomotive was built at the works in 1864...

, England and made its first run on 1 August 2008. It entered main line service later in 2008, to great public acclaim. Demonstration trips in France and Germany have been planned. As of 2009 over half-a-dozen projects to build working replicas of extinct steam engines are going ahead, in many cases using existing parts from other types to build them. Examples include BR Class 6MT Hengist , BR Class 3MT no. 82045, BR Class 2MT no. 84030, Brighton Atlantic Beachy Head , the LMS "Patriot
LMS Patriot Class
The Patriot Class was a class of 52 express passenger steam locomotives built for the London Midland and Scottish Railway. The first locomotive of the class was built in 1930 and the last in 1934. All of the Patriot class locomotives were withdrawn from service by 1965...

 45551 The Unknown Warrior" project, and the GWR "Saint
GWR 2900 Class
The Great Western Railway 2900 or Saint Class were a class of 4-6-0 steam locomotives for passenger train work. Number 2925 Saint Martin was later rebuilt as the prototype Hall Class locomotive, and renumbered 4900.-Prototypes:...

" 2999 Lady of Legend, 1014 "County
GWR 1000 Class
The Great Western Railway 1000 Class or County Class was a class of 4-6-0 steam locomotive. Thirty were built between 1945 and 1947, but all were withdrawn and scrapped in the early 1960s. A replica locomotive is under construction.-Overview:...

" of Glamorgan and 6880 Betton "Grange
GWR 6800 Class
The Great Western Railway 6800 Class or Grange Class was a mixed traffic class of 4-6-0 steam locomotive. There were 80 in the class, all built at the Swindon works.-History:The GWR locomotive standardisation policy pursued by G.J...

" projects.

In 1980 American financier Ross Rowland
Ross Rowland
Ross E. Rowland, Jr. is a significant figure in the United States railroad preservation, recreation and enthusiast communities who is closely identified with running public and demonstration excursions on existing railroads utilizing steam locomotives....

 established American Coal Enterprises to develop a modernised coal-fired steam locomotive. His ACE 3000 concept
Ross Rowland
Ross E. Rowland, Jr. is a significant figure in the United States railroad preservation, recreation and enthusiast communities who is closely identified with running public and demonstration excursions on existing railroads utilizing steam locomotives....

 attracted considerable attention, but never materialised.

In 1998, in his book "The Red Devil and Other Tales from the Age of Steam", David Wardale put forward the concept of a high speed, high efficiency "Super Class 5 4-6-0" locomotive for future steam haulage of tour trains on UK main lines. The idea was formalized in 2001 by the formation of 5AT Project dedicated to developing and building the 5AT Advanced Technology Steam Locomotive
5AT Advanced Technology Steam Locomotive
The 5AT Advanced Technology steam locomotive is a conceptual design conceived by the British engineer David Wardale, and first described in his definitive work on modern steam, "The Red Devil and Other Tales from the Age of Steam" ....

, a project that was still active at the start of 2010.

Locations where new builds are taking Place.

GWR 1014 County of Glamorgan & GWR 2999 Lady of Legend, Both being built at Didcot Railway Centre
Didcot Railway Centre
Didcot Railway Centre, located in the town of Didcot in the English county of Oxfordshire, is based around the site of a comprehensive "engine shed" which became redundant after the nationalisation of the UK railways, due to the gradual changeover from steam to diesel motive power.-Description:The...

.

GWR 6880 Betton Grange & LMS 45551 The Unknown Warrior, Both being built at Llangollen Railway
Llangollen Railway
The Llangollen Railway is a volunteer-run preserved railway in Denbighshire, Wales, which operates between Llangollen and Carrog; at long, it is the longest preserved standard gauge line in Wales and operates daily in Summer as well as weekends throughout the Winter months using a wide variety of...

.

BR 82045, Severn Valley Railway.

BR 84030, Bluebell Railway.

Steam locomotives in popular culture


Over the years, steam locomotives have become a very popular image in representations of trains. Many toy trains based on steam locomotives are made, thereby making the image iconic with trains to children. Their popularity has led to steam locomotives being portrayed in fictional works about trains, most notably The Railway Series
The Railway Series
The Railway Series is a set of story books about a railway system located on the fictional Island of Sodor. There are 42 books in the series, the first being published in 1945. Twenty-six were written by the Rev. W. Awdry, up to 1972. A further 16 were written by his son, Christopher Awdry; 14...

by the Rev W. V. Awdry and The Little Engine That Could
The Little Engine That Could
The Little Engine that Could is a children's story that appeared in the United States of America. The book is used to teach children the value of optimism and hard work...

by Watty Piper. Steam locomotives have also been "stars" in many television shows about trains, such as Thomas the Tank Engine and Friends
Thomas the Tank Engine and Friends
Thomas and Friends is a British children's television series, first broadcast on the ITV network in September 1984. Until 2003, it was named Thomas the Tank Engine and Friends. This series was shot on 35mm film...

, based on characters from the books by Awdry.

There is also the Hogwarts Express from J.K. Rowling's Harry Potter
Harry Potter
Harry Potter is a series of seven fantasy novels written by the British author J. K. Rowling. The books chronicle the adventures of the adolescent wizard Harry Potter and his best friends Ron Weasley and Hermione Granger, all of whom are students at Hogwarts School of Witchcraft and Wizardry...

 series, which in the films is portrayed by the GWR 4900 Class 5972 Olton Hall
GWR 4900 Class 5972 Olton Hall
The steam locomotive no. 5972 "Olton Hall" is a 4-6-0 Hall class locomotive.In the 2000s the locomotive achieved fame after it was used to haul the "Hogwarts Express" in the Harry Potter series of films.-Service:...

 steam engine in special Hogwarts livery. The Hogwarts Express is so popular in its own right that it is an attraction at The Wizarding World of Harry Potter section of the Universal Studios Islands of Adventure
Islands of Adventure
Universal's Islands of Adventure is a theme park located in Orlando, Florida. It opened May 28, 1999 as part of an expansion that, along with CityWalk Entertainment District, the Portofino Bay Hotel, and Hard Rock hotel, converted Universal Studios Florida into the Universal Orlando Resort...

 amusement park in Florida.

Coins


Steam locomotives are a main topic for numerous collectors and bullion coins.

The 1950 Silver 5 Peso coin of Mexico has a steam locomotive on its reverse as the prominent feature.

The recent 20 euro Biedermeier Period coin, minted June 11, 2003, shows on the obverse an early model steam locomotive (the AJAX) on Austria's first railway line, the Kaiser Ferdinand's Nordbahn. The AJAX can still be seen today in the Austrian railway museum.

As part of the 50 State Quarters
50 State Quarters
The 50 State Quarters program is the release of a series of circulating commemorative coins by the United States Mint. Between 1999 and 2008, it featured each of the 50 U.S. states on unique designs for the reverse of the quarter....

 program, the quarter representing the U.S. state of Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...

 depicts the ceremony where the two halves of the First Transcontinental Railroad
First Transcontinental Railroad
The First Transcontinental Railroad was a railroad line built in the United States of America between 1863 and 1869 by the Central Pacific Railroad of California and the Union Pacific Railroad that connected its statutory Eastern terminus at Council Bluffs, Iowa/Omaha, Nebraska The First...

 met at Promontory Summit in 1869. The coin recreates a popular image from the ceremony with steam locomotives from each company facing each other while the golden spike
Golden spike
The "Golden Spike" is the ceremonial final spike driven by Leland Stanford to join the rails of the First Transcontinental Railroad across the United States connecting the Central Pacific and Union Pacific railroads on May 10, 1869, at Promontory Summit, Utah Territory...

 is being driven.

See also


General
  • History of rail transport
    History of rail transport
    The history of rail transport dates back nearly 500 years and includes systems with man or horse power and rails of wood or stone. Modern rail transport systems first appeared in England in the 1820s...

  • List of steam technology patents
  • Live steam
    Live steam
    Live steam is steam under pressure, obtained by heating water in a boiler. The steam is used to operate stationary or moving equipment.A live steam machine or device is one powered by steam, but the term is usually reserved for those that are replicas, scale models, toys, or otherwise used for...

  • Steam locomotive production
    Steam locomotive production
    - Early 20th Century :Early 20th Century locomotive production in the USA included units made for both domestic and export markets. Foreign market production increased significantly during and immediately after World War I...

  • Steam turbine locomotive
    Steam turbine locomotive
    A steam turbine locomotive is a steam locomotive which transmits steam power to the wheels via a steam turbine. Numerous attempts at this type of locomotive were made, mostly without success...

  • Steam railroad
    Steam railroad
    Steam railroad is a term used in the United States to distinguish conventional heavy railroads from street railways, interurban streetcar lines, and other light railways usually dedicated primarily to passenger transport....

  • Timeline of railway history
    Timeline of railway history
    -Ancient times:* ca. 600 BC - A basic form of the railway, the rutway, - existed in ancient Greek and Roman times, the most important being the ship trackway Diolkos across the Isthmus of Corinth...


Types of steam locomotives
  • Beyer-Garratt
  • Duplex
    Duplex locomotive
    A duplex locomotive is a steam locomotive that divides the driving force on its wheels by using two pairs of cylinders rigidly mounted to a single locomotive frame; it is not an articulated locomotive...

  • Geared steam locomotive
    Geared steam locomotive
    A geared steam locomotive is a type of steam locomotive which uses reduction gearing in the drivetrain, as opposed to the common directly driven design....

  • High-pressure steam locomotive
  • Mallet
  • Steam dummy
    Steam dummy
    A steam dummy or dummy engine, in the United States of America and Canada, was a steam engine enclosed in a wooden box structure made to resemble a railroad passenger coach....

  • 5AT Advanced Technology Steam Locomotive
    5AT Advanced Technology Steam Locomotive
    The 5AT Advanced Technology steam locomotive is a conceptual design conceived by the British engineer David Wardale, and first described in his definitive work on modern steam, "The Red Devil and Other Tales from the Age of Steam" ....

  • Double Fairlie
  • Cab forward
    Cab forward
    The term cab forward refers to various rail and road vehicle designs which place the driver's compartment substantially farther towards the front than is common practice.- Rail locomotives :...


Historic locomotives

  • Stephenson's Rocket
    Stephenson's Rocket
    Stephenson's Rocket was an early steam locomotive of 0-2-2 wheel arrangement, built in Newcastle Upon Tyne at the Forth Street Works of Robert Stephenson and Company in 1829.- Design innovations :...

  • Fairy Queen
    Fairy Queen (locomotive)
    The Fairy Queen, built in 1855, is the world's oldest steam locomotive in regular operation today, plying between New Delhi to Alwar in India. The locomotive was certified by the Guinness Book of Records to be the oldest operational locomotive after the Rajasthan government invoked it in 2004 to...

  • Catch me who can
    Catch me who can
    Catch Me Who Can was the fourth and last steam railway locomotive created by Richard Trevithick, . Built in 1808 by Rastrick and Hazledine at their foundry in Bridgnorth, England...

  • Invicta
    Invicta (locomotive)
    Invicta is an early steam locomotive built by Robert Stephenson and Company in Newcastle-upon-Tyne in 1829. She was the twentieth locomotive built by Stephenson, being built immediately after Rocket.-History:...

  • Tom Thumb
    Tom Thumb (locomotive)
    Tom Thumb was the first American-built steam locomotive used on a common-carrier railroad. Designed and built by Peter Cooper in 1830, it was designed to convince owners of the newly formed Baltimore and Ohio Railroad to use steam engines...

  • John Bull
    John Bull (locomotive)
    John Bull is a British-built railroad steam locomotive that operated in the United States. It was operated for the first time on September 15, 1831, and it became the oldest operable steam locomotive in the world when the Smithsonian Institution operated it in 1981...

  • Reuben Wells
    Reuben Wells (locomotive)
    The Reuben Wells is a steam locomotive in the permanent collection of The Children's Museum of Indianapolis located in Indianapolis, Indiana, United States...

  • LMR 57 Lion
    LMR 57 Lion
    The Liverpool and Manchester Railway 57 Lion is an early 0-4-2 steam locomotive. One of a pair designed for hauling freight , built by Todd, Kitson & Laird of Leeds in 1838.-History:...

  • Locomotion No 1
    Locomotion No 1
    Locomotion No. 1 is an early British steam locomotive. Built by George and Robert Stephenson's company Robert Stephenson and Company in 1825, it hauled the first train on the Stockton and Darlington Railway on 27 September 1825....

  • Novelty
    Novelty (locomotive)
    Novelty was an early steam locomotive built by John Ericsson and John Braithwaite to take part in the Rainhill Trials in 1829.It was an 0-2-2WT locomotive and is now regarded as the very first tank engine. It had a unique design of boiler and a number of other novel design features...

  • GKB 671
  • Union Pacific No. 119
    Union Pacific No. 119
    The No. 119 was a 4-4-0 steam locomotive which made history as one of the two locomotives to meet at Promontory Summit during the Golden Spike ceremony commemorating the completion of the First Transcontinental Railroad.No...

  • Jupiter
    Jupiter (locomotive)
    The Jupiter was a 4-4-0 steam locomotive which made history as one of the two locomotives The Jupiter (officially known as Central Pacific Railroad #60) was a 4-4-0 steam locomotive which made history as one of the two locomotives The Jupiter (officially known as Central Pacific Railroad #60) was...

  • City of Truro
    GWR 3700 Class 3440 City of Truro
    Number 3440 City Of Truro is a Great Western Railway 3700 Class 4-4-0 locomotive, designed by George Jackson Churchward and built at the GWR Swindon Works in 1903. . It is one of the contenders for the first steam locomotive to travel in excess of...

  • Flying Scotsman
    LNER Class A3 4472 Flying Scotsman
    The LNER Class A3 Pacific locomotive No. 4472 Flying Scotsman was built in 1923 for the London and North Eastern Railway at Doncaster Works to a design of H.N. Gresley...

  • NYC Niagara
    NYC Niagara
    The New York Central Railroad Niagara was a type of steam locomotive named after the Niagara River and Falls.They were express mixed traffic locomotives with a wheel arrangement of 4-8-4 in the Whyte notation....

  • Mallard
    LNER Class A4 4468 Mallard
    Number 4468 Mallard is a London and North Eastern Railway Class A4 4-6-2 Pacific steam locomotive built at Doncaster, England in 1938. While in other respects a relatively typical member of its class, it is historically significant for being the holder of the official world speed record for steam...

  • Sir Nigel Gresley
    LNER Class A4 4498 Sir Nigel Gresley
    London and North Eastern Railway A4 Class number 4498 , 7 and 60007 , namedSir Nigel Gresley is a preserved British steam locomotive.-Liveries:...

  • Evening Star
  • Union Pacific 844
    Union Pacific 844
    Union Pacific 844 is a 4-8-4 steam locomotive owned by Union Pacific Railroad. It was the last steam locomotive delivered to Union Pacific and is unique in that it is the only steam locomotive never retired by a North American Class I railroad....

  • Union Pacific Big Boy
    Union Pacific Big Boy
    Big Boy was the name of the Union Pacific Railroad's 4000-class 4-8-8-4 articulated steam locomotives, built between 1941 and 1944 by American Locomotive Company...

  • Tornado
    LNER Peppercorn Class A1 60163 Tornado
    60163 Tornado is a main-line steam locomotive built in Darlington, England. Completed in 2008, Tornado was the first such locomotive built in the United Kingdom since Evening Star, the last steam locomotive built by British Railways, in 1960...

  • 3801

Further reading


  • C. E. Wolff, Modern Locomotive Practice: A Treatise on the Design, Construction, and Working of Steam Locomotives (Manchester, England, 1903)
  • Henry Greenly, Model Locomotive (New York, 1905)
  • G. R. Henderson, Cost of Locomotive Operation (New York, 1906)
  • W. E. Dalby, Economical Working of Locomotives (London, 1906)
  • A. I. Taylor, Modern British Locomotives (New York, 1907)
  • E. L. Ahrons, The Development of British Locomotive Design (London, 1914)
  • E. L. Ahrons, Steam Engine Construction and Maintenance (London, 1921)
  • J. F. Gairns, Locomotive Compounding and Superheating (Philadelphia, 1907)
  • Angus Sinclair, Development of the Locomotive Engine (New York, 1907)
  • Vaughn Pendred, The Railway Locomotive, What it is and Why it is What it is (London, 1908)
  • Brosius and Koch, Die Schule des Lokomotivführers (thirteenth edition, three volumes, Wiesbaden, 1909–1914)
  • G. L. Fowler, Locomotive Breakdowns, Emergencies, and their Remedies (seventh edition, New York, 1911)
  • Fisher and Williams, Pocket Edition of Locomotive Engineering (Chicago, 1911)
  • T. A. Annis, Modern Locomotives (Adrian Michigan, 1912)
  • C. E. Allen, Modern Locomotive (Cambridge, England, 1912)
  • W. G. Knight, Practical Questions on Locomotive Operating (Boston, 1913)
  • G. R. Henderson, Recent Development of the Locomotive (Philadelphia, 1913)
  • Wright and Swift (editors) Locomotive Dictionary (third edition, Philadelphia, 1913)
  • Roberts and Smith, Practical Locomotive Operating (Philadelphia, 1913)
  • E. Prothero, Railways of the World (New York, 1914)
  • M. M. Kirkman
    Marshall Monroe Kirkman
    Marshall Monroe Kirkman was an American authority on railways, born in Illinois. He entered the service of the Chicago and North Western Railway in 1856 and rose to the position of vice-president in 1889. He wrote extensively on the subject of railways...

    , The Locomotive (Chicago, 1914)
  • C. L. Dickerson, The Locomotive and Things You Should Know About it (Clinton, Illinois, 1914)
  • P. W. B. Semmens, A. J. Goldfinch, How Steam Locomotives Really Work (Oxford University Press, USA, 2004) ISBN 0-19-860782-2
  • Gerald A Dee, A Lifetime of Railway Photography in Photographer Profile, Train Hobby Publications, Studfield, 1998. (Australian steam)
  • Leon Oberg, Locomotives of Australia, Reed, Sydney, 1975.
  • Swengel, F. M. The American Steam Locomotive; Vol. 1. The Evolution of the American Steam Locomotive, Midwest Rail Publication, Iowa, 1967.
  • Раков В.А. Локомотивы отечественных железных дорог 1845-1955 Транспорт, Москва, 1995
    (Rakov V.A. Locomotives of fatherland's railways 1845-1955 Transport, Moscow, 1995 (in Russian))
  • J.J.G. Koopmans: The fire burns much better ... NL-Venray 2006, ISBN 90-6464-013-0


External links