Funnel (ship)
Encyclopedia
A funnel is the smokestack or chimney
on a ship used to expel boiler
steam and smoke or engine exhaust
. They can also be known in as stacks.
In steam ships the funnels also served to help induce a convection draught through the boilers.
had 5 when launched), but as efficiency increased new machinery needed fewer funnels.
during both the First World War and Second World War was to disguise their ship's outline, and this included using false funnels or by changing the height or diameter of the actual funnel(s).
and ferries such as Red Funnel
) were quick to recognise the publicity value of distinctive funnels, both in terms of shape, number of funnels, and the colours they were painted. Each company would have their own "house colours", which were often used in publicity material as well as for recognition.
For example, the RMS Queen Elizabeth 2
was built with very distinctive wind-scoops at the base of her funnel. When fitted with new diesel engines in 1987, which had a different exhaust requirement to the old boilers, the new funnel was built to the same silhouette as the old one, in order to retain this distinctive recognition feature.
Chimney
A chimney is a structure for venting hot flue gases or smoke from a boiler, stove, furnace or fireplace to the outside atmosphere. Chimneys are typically vertical, or as near as possible to vertical, to ensure that the gases flow smoothly, drawing air into the combustion in what is known as the...
on a ship used to expel 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:...
steam and smoke or engine exhaust
Exhaust gas
Exhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas, gasoline/petrol, diesel fuel, fuel oil or coal. According to the type of engine, it is discharged into the atmosphere through an exhaust pipe, flue gas stack or propelling nozzle.It often disperses...
. They can also be known in as stacks.
Purpose
The primary purpose of a ship's funnel(s) is to lift the exhaust gases clear of the deck, in order not to foul the ship's structure or decks, and to avoid impairing the ability of the crew to carry out their duties.In steam ships the funnels also served to help induce a convection draught through the boilers.
Funnel Area
The required funnel cross-sectional area is determined by the volume of exhaust gases produced by the propulsion plant. Often this area is too great for a single funnel. Early steam vessels needed multiple funnels (SS Great EasternSS Great Eastern
SS Great Eastern was an iron sailing steam ship designed by Isambard Kingdom Brunel, and built by J. Scott Russell & Co. at Millwall on the River Thames, London. She was by far the largest ship ever built at the time of her 1858 launch, and had the capacity to carry 4,000 passengers around the...
had 5 when launched), but as efficiency increased new machinery needed fewer funnels.
Design
Since the introduction of steam-power to ships in the 19th century, the funnel has been a distinctive feature of the silhouette of a vessel, and used for recognition purposes.Military deception
A key part of the deception practiced by ships carrying out commerce raidingCommerce raiding
Commerce raiding or guerre de course is a form of naval warfare used to destroy or disrupt the logistics of an enemy on the open sea by attacking its merchant shipping, rather than engaging the combatants themselves or enforcing a blockade against them.Commerce raiding was heavily criticised by...
during both the First World War and Second World War was to disguise their ship's outline, and this included using false funnels or by changing the height or diameter of the actual funnel(s).
Merchant Shipping
Merchant shipping companies (and particularly liner companies such as Cunard LineCunard Line
Cunard Line is a British-American owned shipping company based at Carnival House in Southampton, England and operated by Carnival UK. It has been a leading operator of passenger ships on the North Atlantic for over a century...
and ferries such as Red Funnel
Red Funnel
The Southampton Isle of Wight and South of England Royal Mail Steam Packet Company Limited, which trades as Red Funnel, is a ferry company that carries passengers and vehicles on routes between the English mainland and the Isle of Wight...
) were quick to recognise the publicity value of distinctive funnels, both in terms of shape, number of funnels, and the colours they were painted. Each company would have their own "house colours", which were often used in publicity material as well as for recognition.
For example, the RMS Queen Elizabeth 2
RMS Queen Elizabeth 2
Queen Elizabeth 2, often referred to simply as the QE2, is an ocean liner that was operated by Cunard from 1969 to 2008. Following her retirement from cruising, she is now owned by Istithmar...
was built with very distinctive wind-scoops at the base of her funnel. When fitted with new diesel engines in 1987, which had a different exhaust requirement to the old boilers, the new funnel was built to the same silhouette as the old one, in order to retain this distinctive recognition feature.