The Great Central Railway Class 8H (LNER Class S1) was a class of 0-8-4T

steam Steam is a substance containing water in the gas phase, and sometimes also an aerosol of liquid water droplets, or air. This may occur due to evaporation or due to boiling, where heat is applied until water reaches the enthalpy of vaporization ...

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 a more traditional tender. Most tank engines also have bunkers (or fuel tanks) to hold fuel; in a tender-tank locom ...

s designed by John G. Robinson for hump shunting at

Wath marshalling yard Wath marshalling yard, also known as Wath concentration yard (), was a large railway marshalling yard specifically designed for the concentration of coal traffic. It was set at the heart of the South Yorkshire Coalfield, at Wath-upon-Dearne, a ...

Overview

Four locomotives were built in 1907/1908 for the

Great Central Railway The Great Central Railway in England was formed when the Manchester, Sheffield and Lincolnshire Railway changed its name in 1897, anticipating the opening in 1899 of its London Extension. On 1 January 1923, the company was grouped into the ...

. They were fitted with three cylinders. This gave a more even

torque In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of th ...

than with a 2-cylinder locomotive and reduced the risk of wheelslip under heavy load. All four passed into

London and North Eastern Railway The London and North Eastern Railway (LNER) was the second largest (after LMS) of the " Big Four" railway companies created by the Railways Act 1921 in Britain. It operated from 1 January 1923 until nationalisation on 1 January 1948. At th ...

ownership at the 1923

grouping Grouping may refer to: * Muenchian grouping * Principles of grouping * Railways Act 1921, also known as Grouping Act, a reorganisation of the British railway system * Grouping (firearms), the pattern of multiple shots from a sidearm See also ...

. At the time all four locomotives were allocated to

Mexborough engine shed Mexborough engine shed was an engine shed in Swinton, in South Yorkshire, England. It was built by the Great Central Railway and opened in 1875. The shed was built slightly to the west of the current Mexborough station on land between the Riv ...

. These were powerful locomotives but even more power was required so, in 1930, one locomotive was fitted with a

superheater 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 ar ...

and a

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 the lead truck on the tender. A rocking idler gear permits it to be put into operation by the drive ...

and classified S1/2. Two new locomotives (with superheaters and boosters) were built by the LNER in 1932 and classified S1/3. The remaining (non-booster) locomotives were classified S1/1 and were also fitted with superheaters. All the boosters were removed in 1943. All six locomotives passed into

British Railways British Railways (BR), which from 1965 traded as British Rail, was a state-owned company that operated most of the overground rail transport in Great Britain from 1948 to 1997. It was formed from the nationalisation of the Big Four British rai ...

ownership in 1948 and were numbered 69900-69905.

Dimensions

* Locomotive weight: ** S1/1, 99 tons 6 cwt ** S1/2, 99 tons 2 cwt ** S1/3, 99 tons 1 cwt * Superheater: ** S1/1, No, but fitted later ** S1/2, Yes ** S1/3, Yes * Tractive effort, ** Booster tractive effort, *** Combined tractive effort, For terminology, see

Steam locomotive components __NOTOC__ This article is a glossary of the main components found on a typical steam locomotive. The diagram, which is not to scale, is a composite of various designs in the late steam era. Some components shown are not the same, or are not pre ...

References

* *

External links

LNER Encyclopedia
{{DEFAULTSORT:GCR Class 08H 08H 0-8-4T locomotives Railway locomotives introduced in 1907 Scrapped locomotives Standard gauge steam locomotives of Great Britain Shunting locomotives