The LNER Class Y3 was a class of

0-4-0 Under the Whyte notation for the classification of steam locomotives, represents one of the simplest possible types, that with two axles and four coupled wheels, all of which are driven. The wheels on the earliest four-coupled locomotives were ...

geared steam locomotive A geared steam locomotive is a type of steam locomotive which uses gearing, usually reduction gearing, in the drivetrain, as opposed to the common directly driven design. This gearing is part of the machinery within the locomotive and should n ...

s built by

Sentinel Waggon Works Sentinel Waggon Works Ltd was a British company based in Shrewsbury, Shropshire that made steam-powered lorries ( steam wagons), railway locomotives, and later, diesel engined lorries, buses and locomotives. History Alley & MacLellan, Se ...

for the London and North Eastern Railway and introduced in 1927. They passed into British Railways ownership in 1948 and were numbered 68154-68185.Ian Allan ABC of British Railways Locomotives, 1948 edition, part 4, page 47 At least one was based at Immingham in 1950.

Power unit

The

superheated A superheater is a device used to convert saturated steam or wet steam into superheated steam or dry steam. Superheated steam is used in steam turbines for electricity generation, steam engines, and in processes such as steam reforming. There are ...

vertical water-tube boiler and the

engine An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy. Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power ...

were similar to those used in Sentinel

steam wagon A steam wagon (or steam lorry, steam waggon or steamtruck) is a steam-powered truck for carrying freight. It was the earliest form of lorry (truck) and came in two basic forms: ''overtype'' and ''undertype'', the distinction being the position ...

s. The engines had

poppet valve A poppet valve (also called mushroom valve) is a valve typically used to control the timing and quantity of gas or vapor flow into an engine. It consists of a hole or open-ended chamber, usually round or oval in cross-section, and a plug, usua ...

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.

Transmission

Final drive to the wheels was by sprocket chain. Some locomotives had a sprocket

gear ratio A gear train is a mechanical system formed by mounting gears on a frame so the teeth of the gears engage. Gear teeth are designed to ensure the Pitch circle diameter (gears), pitch circles of engaging gears roll on each other without slipping, pr ...

of 19:19 and others 15:19. In addition, there was a two-speed

gearbox Propulsion transmission is the mode of transmitting and controlling propulsion power of a machine. The term ''transmission'' properly refers to the whole drivetrain, including clutch, gearbox, prop shaft (for rear-wheel drive vehicles), differe ...

but gears could only be changed while the locomotive was stationary. Tractive effort was: * Ratio 19:19, Low gear , High gear (68154-68179 and 68184-68185) * Ratio 15:19, Low gear , High gear (68180-68183)

References

Sources

External links

LNER encyclopedia
{{DEFAULTSORT:Lner Class Y03 Sentinel locomotives Y03 0-4-0T locomotives Railway locomotives introduced in 1927 Scrapped locomotives Standard gauge steam locomotives of Great Britain Shunting locomotives