London Underground diesel locomotives
Encyclopedia
Diesel locomotives have seen limited use on the London Underground, largely because exhaust gases cannot be discharged when the vehicles are working in tunnels. A prototype diesel engine was built in 1939 from two 1915 stock motor cars, which was expected to be part of a batch of ten, but experience with battery locomotives
showed that these were a better alternative. Three 0-6-0 diesels were obtained in 1971, to replace the last steam engines, but were too short to operate the signalling system, and too heavy for some of the bridges. In 1996, fourteen diesels were supplied by Schöma
of Germany
, which were used during the fitting out of the Jubilee line
tunnels. They were fitted with exhaust scrubbers, to enable them to work in the tunnels. To speed up track renewals on the subsurface lines, class 66
locomotives have been hired in since 2006 to handle permanent way trains, but again suffer from being too heavy for some of the bridges. Because they are not fitted with tripcock safety devices, and pull trains much longer than the signalling system is designed for, they are restricted to slow speed running.
which could work through London's tube tunnels was first considered in 1936, and work began on its construction at Acton Works in 1939. It was designed to use its diesel engine
when in the open air, but to draw current from the conductor rails when underground. Two Brush
built 1915 Stock
(also known as 'Ealing Stock') driving motors, numbered 3937 and 3941, which had been withdrawn from the Central London line, were converted into the electro-diesel locomotive
. The work involved scrapping the passenger saloons and joining the two driving ends together to form a double ended locomotive. The central bay held a six-cylinder two-stroke diesel engine, manufactured by Petters
, which was coupled to a direct current
generator
.
showed that these were a better solution.
-engined diesel-hydraulic locomotives were built in 1967-68, and were supplied to an open-cast iron ore mine at Corby
. When the iron ore was worked out, the locomotives were surplus to requirements, and were acquired by London Underground in 1971. They were numbered in the range DL81-DL83. All three were standard 0-6-0DH Sentinel diesel shunters obtained from Thomas Hill (Rotherham) Ltd
(the Rolls Royce/Sentinel dealer). They were painted dark green and operated at Neasden and Lillie Bridge depots where they replaced the last of the ex-GWR pannier tank steam locomotives.
The locomotives had a wheelbase of only 9 in 8 in (2.95 m), and this was too short to operate the track circuits. Since this made their use impracticable, each was permanently coupled to a tender, which consisted of a bogie removed from a redundant District line
Q Stock
car. The weight of the bogie was increased to 17 tons, and it was fitted with tripcocks and sleet brushes, so that it could be used for clearing snow and ice from the current rails. Although the tenders were permanently coupled to the locomotives, they carried separate numbers, and were identified as DT81, DT82 and DT83. The tender increased the wheelbase to 28 in 6 in (8.69 m).
One locomotive was normally operational at each of the depots, with the third kept as a spare. Transfers between the works occurred when maintenance or repairs were necessary. Movement outside of the depots was severely restricted when the civil engineering department decided that the short wheelbase and 16-ton axle loading might cause overloading problems on a number of bridges. Both the free end (front) of the locomotive and the tender were fitted with 'Ward' type couplers as well as normal buffers and couplings to allow them the couple to almost any Departmental rolling stock (at the time).
Two locomotives have been preserved; no. DL82 on the Mid-Norfolk Railway
and no. DL83 on the Nene Valley Railway
. The third locomotive, no. DL81, was sold for further use with an industrial user.
extension project, 14 diesel-hydraulic locomotives were purchased from Schöma
of Germany
to assist in equipping the tunnels prior to electrification. Weighing 33.88 tons, they are 28 feet (8.5 m) long, and are powered by 500 hp six-cylinder inline diesel engines, which give them a maximum speed of 31 mile per hour. They entered service from February 1996, are built to tube tunnel loading gauge, and are equipped with exhaust scrubbers to prevent soot and other particles from being expelled into the tunnels. The locomotives are now owned by TransPlant and have since been used on other engineering projects. When not in use they can be found inside Lillie Bridge depot or Ruislip depot.
locomotives from GB Railfreight
. They were first used in August 2006, pulling engineering trains nearly 440 yards (402.3 m) long, consisting of wagons and high-output track laying equipment. They are capable of hauling 470 yards (429.8 m) trains, reducing the number of trains needed to supply materials to relay a typical weekend possession of track from 30 to 8, and increasing the amount of track that can be renewed as a consequence. One disadvantage of the heavier locomotives is that bridges on the District line
needed to be strengthened to carry the extra weight. While working on the network, they are restricted to 15 mile per hour, since they are not fitted with tripcocks, and the signalling infrastructure is only designed to cope with trains having a maximum length of 150 yards (137.2 m).
London Underground battery-electric locomotives
London Underground Battery-electric locomotives, most commonly known as battery locomotives are used for hauling engineers' trains, as they can operate when the electric traction current is switched off...
showed that these were a better alternative. Three 0-6-0 diesels were obtained in 1971, to replace the last steam engines, but were too short to operate the signalling system, and too heavy for some of the bridges. In 1996, fourteen diesels were supplied by Schöma
Schöma
Schöma is a company based in Diepholz, Germany, specialising in the construction of small diesel railway engines.-External links:*...
of 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...
, which were used during the fitting out of the Jubilee line
Jubilee Line
The Jubilee line is a line on the London Underground , in the United Kingdom. It was built in two major sections—initially to Charing Cross, in central London, and later extended, in 1999, to Stratford, in east London. The later stations are larger and have special safety features, both aspects...
tunnels. They were fitted with exhaust scrubbers, to enable them to work in the tunnels. To speed up track renewals on the subsurface lines, class 66
British Rail Class 66
The Class 66 is a six axle diesel electric freight locomotive developed in part from the British Rail Class 59, for use on the railways of the UK. Since its introduction the class has been successful and has been sold to British and other European railway companies...
locomotives have been hired in since 2006 to handle permanent way trains, but again suffer from being too heavy for some of the bridges. Because they are not fitted with tripcock safety devices, and pull trains much longer than the signalling system is designed for, they are restricted to slow speed running.
Design
The design of a prototype diesel locomotiveDiesel 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...
which could work through London's tube tunnels was first considered in 1936, and work began on its construction at Acton Works in 1939. It was designed to use its diesel engine
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...
when in the open air, but to draw current from the conductor rails when underground. Two Brush
Brush Traction
This article is about a British rail-locomotive maker. For the Detroit auto-maker, see Brush Motor Car CompanyBrush Traction is a manufacturer and maintainer of railway locomotives, part of the FKI group , based at Loughborough in Leicestershire, England situated alongside the Midland Main Line.-...
built 1915 Stock
London Underground 1915 Stock
Twenty-four 1915 Tube Stock driving motor cars were built by Brush for the Central London Railway's extension from Wood Lane to Ealing Broadway...
(also known as 'Ealing Stock') driving motors, numbered 3937 and 3941, which had been withdrawn from the Central London line, were converted into the electro-diesel locomotive
Electro-diesel locomotive
An Electro-diesel locomotive is powered either from an electricity supply or by using the onboard diesel engine...
. The work involved scrapping the passenger saloons and joining the two driving ends together to form a double ended locomotive. The central bay held a six-cylinder two-stroke diesel engine, manufactured by Petters
Petters Limited
Petters Limited , were a maker of stationary petrol and diesel engines from 1896 onwards.In 1915 Petter founded Westland Aircraft Works ....
, which was coupled to a direct current
Direct current
Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...
generator
Electrical generator
In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge to flow through an external electrical circuit. It is analogous to a water pump, which causes water to flow...
.
Construction
The prototype, which was the first electro-diesel locomotive to be constructed in Britain, was completed in November 1940, and was painted in Metropolitan 'Lake', with gold lining. It was intended to build ten similar locomotives, to replace the fleet of steam engines, and a further 18 withdrawn motor cars were stored at Cockfosters depot with this in mind. The construction of further locomotives was delayed by the outbreak of the Second World War, and experience with the 1935 fleet of battery locomotivesLondon Underground battery-electric locomotives
London Underground Battery-electric locomotives, most commonly known as battery locomotives are used for hauling engineers' trains, as they can operate when the electric traction current is switched off...
showed that these were a better solution.
Service
DEL120 entered normal service in 1941, but was not a success, as the complicated operating system resulted in frequent breakdowns and repairs. It was used initially around Watford, and was transferred to Hainault to work ballast trains after an overhaul in 1952. It was moved to Golders Green depot temporarily, to operate a works train while an experimental ground wheel lathe was installed. The diesel engine was removed in 1954, after which it was only used for shunting, initially at Hainault and later at Acton. It was not ideal as a shunting engine, as visibility from the cab was poor, and access difficult, and so it was idle from 1956, finally being scrapped in 1958.DL81-DL83
Three Rolls-RoyceRolls-Royce Limited
Rolls-Royce Limited was a renowned British car and, from 1914 on, aero-engine manufacturing company founded by Charles Stewart Rolls and Henry Royce on 15 March 1906 as the result of a partnership formed in 1904....
-engined diesel-hydraulic locomotives were built in 1967-68, and were supplied to an open-cast iron ore mine at Corby
Corby
Corby Town is a town and borough located in the county of Northamptonshire. Corby Town is 23 miles north-east of the county town, Northampton. The borough had a population of 53,174 at the 2001 Census; the town on its own accounted for 49,222 of this figure...
. When the iron ore was worked out, the locomotives were surplus to requirements, and were acquired by London Underground in 1971. They were numbered in the range DL81-DL83. All three were standard 0-6-0DH Sentinel diesel shunters obtained from Thomas Hill (Rotherham) Ltd
Thomas Hill (Rotherham) Ltd
Thomas Hill Limited was a company which repaired and sold steam road vehicles, diesel and electric road vehicles and railway locomotives. It later made its name building and rebuilding diesel locomotives.-History:...
(the Rolls Royce/Sentinel dealer). They were painted dark green and operated at Neasden and Lillie Bridge depots where they replaced the last of the ex-GWR pannier tank steam locomotives.
The locomotives had a wheelbase of only 9 in 8 in (2.95 m), and this was too short to operate the track circuits. Since this made their use impracticable, each was permanently coupled to a tender, which consisted of a bogie removed from a redundant District line
District Line
The District line is a line of the London Underground, coloured green on the Tube map. It is a "sub-surface" line, running through the central area in shallow cut-and-cover tunnels. It is the busiest of the sub-surface lines. Out of the 60 stations served, 25 are underground...
Q Stock
London Underground Q Stock
The Q Stock consisted of various District Line trains built from 1923 until the mid 1930s, originally built with manually operated sliding doors. Following conversion to air operated doors, the trains became collectively known as Q Stock...
car. The weight of the bogie was increased to 17 tons, and it was fitted with tripcocks and sleet brushes, so that it could be used for clearing snow and ice from the current rails. Although the tenders were permanently coupled to the locomotives, they carried separate numbers, and were identified as DT81, DT82 and DT83. The tender increased the wheelbase to 28 in 6 in (8.69 m).
One locomotive was normally operational at each of the depots, with the third kept as a spare. Transfers between the works occurred when maintenance or repairs were necessary. Movement outside of the depots was severely restricted when the civil engineering department decided that the short wheelbase and 16-ton axle loading might cause overloading problems on a number of bridges. Both the free end (front) of the locomotive and the tender were fitted with 'Ward' type couplers as well as normal buffers and couplings to allow them the couple to almost any Departmental rolling stock (at the time).
Two locomotives have been preserved; no. DL82 on the Mid-Norfolk Railway
Mid-Norfolk Railway
The Mid-Norfolk Railway or MNR is a heritage railway in the English county of Norfolk. Opening as a tourist line in 1997, it is often referred to as a "New Generation" heritage railway....
and no. DL83 on the Nene Valley Railway
Nene Valley Railway
The Nene Valley Railway is a preserved railway in Cambridgeshire, England, running between Peterborough Nene Valley and Yarwell Junction. The line is currently seven and a half miles in length...
. The third locomotive, no. DL81, was sold for further use with an industrial user.
Schöma
In connection with the construction of the Jubilee lineJubilee Line
The Jubilee line is a line on the London Underground , in the United Kingdom. It was built in two major sections—initially to Charing Cross, in central London, and later extended, in 1999, to Stratford, in east London. The later stations are larger and have special safety features, both aspects...
extension project, 14 diesel-hydraulic locomotives were purchased from Schöma
Schöma
Schöma is a company based in Diepholz, Germany, specialising in the construction of small diesel railway engines.-External links:*...
of 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...
to assist in equipping the tunnels prior to electrification. Weighing 33.88 tons, they are 28 feet (8.5 m) long, and are powered by 500 hp six-cylinder inline diesel engines, which give them a maximum speed of 31 mile per hour. They entered service from February 1996, are built to tube tunnel loading gauge, and are equipped with exhaust scrubbers to prevent soot and other particles from being expelled into the tunnels. The locomotives are now owned by TransPlant and have since been used on other engineering projects. When not in use they can be found inside Lillie Bridge depot or Ruislip depot.
Class 66
In order to speed up track replacement works on the London Underground network Metronet contracted five brand new Class 66British Rail Class 66
The Class 66 is a six axle diesel electric freight locomotive developed in part from the British Rail Class 59, for use on the railways of the UK. Since its introduction the class has been successful and has been sold to British and other European railway companies...
locomotives from GB Railfreight
GB Railfreight
GB Railfreight is a British freight train operating company. Formerly called First GBRf, its new owner Eurotunnel bought the company in May 2010.-History:...
. They were first used in August 2006, pulling engineering trains nearly 440 yards (402.3 m) long, consisting of wagons and high-output track laying equipment. They are capable of hauling 470 yards (429.8 m) trains, reducing the number of trains needed to supply materials to relay a typical weekend possession of track from 30 to 8, and increasing the amount of track that can be renewed as a consequence. One disadvantage of the heavier locomotives is that bridges on the District line
District Line
The District line is a line of the London Underground, coloured green on the Tube map. It is a "sub-surface" line, running through the central area in shallow cut-and-cover tunnels. It is the busiest of the sub-surface lines. Out of the 60 stations served, 25 are underground...
needed to be strengthened to carry the extra weight. While working on the network, they are restricted to 15 mile per hour, since they are not fitted with tripcocks, and the signalling infrastructure is only designed to cope with trains having a maximum length of 150 yards (137.2 m).