LNER Class Y3
Encyclopedia
The LNER Class Y3 was a class of 0-4-0
geared steam locomotive
s built by Sentinel Waggon Works
for the London and North Eastern Railway
and introduced in 1927. They passed into British Railways ownership in 1948 and were numbered 68154-68185.
vertical water-tube boiler
and the engine
were similar to those used in Sentinel steam wagon
s. The engines had poppet valve
s and reversing was by sliding camshaft
. The advantage of the water-tube boiler was that steam could be raised much more quickly than with a conventional fire-tube boiler
.
. Some locomotives had a sprocket gear ratio
of 19:19 and others 15:19. In addition, there was a two-speed gearbox
but gears could only be changed while the locomotive was stationary. Tractive effort was:
0-4-0
Under the Whyte notation for the classification of steam locomotives, 0-4-0 represents one of the simplest possible types, that with two axles and four coupled wheels, all of which are driven...
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....
s built by Sentinel Waggon Works
Sentinel Waggon Works
Sentinel Waggon Works Ltd was a British company based in Shrewsbury, Shropshire that made steam-powered lorries, railway locomotives, and later, diesel engined lorries and locomotives.-Alley & MacLellan, Sentinel Works, Jessie Street Glasgow:...
for 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 introduced in 1927. They passed into British Railways ownership in 1948 and were numbered 68154-68185.
Power unit
The superheatedSuperheater
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...
vertical water-tube boiler
Sentinel boiler
The Sentinel boiler was a design of vertical boiler, fitted to the numerous steam waggons built by the Sentinel Waggon Works.The boiler was carefully designed for use in a steam wagon: it was compact, easy to handle whilst driving, and its maintenance features recognised the problems of poor...
and the 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...
were similar to those used in Sentinel steam wagon
Steam wagon
A steam wagon is a steam-powered road vehicle for carrying freight. It was the earliest form of lorry and came in two basic forms: overtype and undertype – the distinction being the position of the engine relative to the boiler...
s. The engines had 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 and reversing was by sliding camshaft
Camshaft
A camshaft is a shaft to which a cam is fastened or of which a cam forms an integral part.-History:An early cam was built into Hellenistic water-driven automata from the 3rd century BC. The camshaft was later described in Iraq by Al-Jazari in 1206. He employed it as part of his automata,...
. The advantage of the water-tube boiler was that steam could be raised much more quickly than with a conventional fire-tube boiler
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...
.
Transmission
Final drive to the wheels was by sprocket chainSprocket
A sprocket or sprocket-wheel is a profiled wheel with teeth, cogs, or even sprockets that mesh with a chain, track or other perforated or indented material. The name 'sprocket' applies generally to any wheel upon which are radial projections that engage a chain passing over it...
. Some locomotives had a sprocket gear ratio
Gear ratio
The gear ratio of a gear train is the ratio of the angular velocity of the input gear to the angular velocity of the output gear, also known as the speed ratio of the gear train. The gear ratio can be computed directly from the numbers of teeth of the various gears that engage to form the gear...
of 19:19 and others 15:19. In addition, there was a two-speed gearbox
Transmission (mechanics)
A machine consists of a power source and a power transmission system, which provides controlled application of the power. Merriam-Webster defines transmission as: an assembly of parts including the speed-changing gears and the propeller shaft by which the power is transmitted from an engine to a...
but gears could only be changed while the locomotive was stationary. Tractive effort was:
- Ratio 19:19, Low gear 12600 lbf (56 kN), High gear 4705 lbf (20.9 kN) (68154-68179 and 68184-68185)
- Ratio 15:19, Low gear 15960 lbf (71 kN), High gear 5960 lbf (26.5 kN)(68180-68183)