GWR 6959 Class
Encyclopedia
The Great Western Railway
(GWR) 6959 Class or Modified Hall Class is a class of 4-6-0
steam locomotive
. They were a development by Frederick Hawksworth
of Charles Collett
's earlier Hall Class.
The Modified Halls marked the most radical change to Swindon Works
' practice since Churchward
's time as chief mechanical engineer
. Hawksworth's use of plate frame
s throughout the design was a daring break with Churchward's practice. The cylinders were cast separately from the smokebox
saddle and bolted to the frames on each side. A stiffening brace was inserted between the frames and extended to form the smokebox saddle. The exhaust pipes leading from the cylinders to the blastpipe
were incorporated into this assembly.
Additionally Churchward's bar framed bogie
which had been adapted for the original Hall in 1924 was replaced by a plate frame structure with individual springing. There were changes too above the running board. Hawksworth decided that the declining quality of coal reaching Great Western depots necessitated a higher degree of superheating. A larger three-row superheater
and header regulator were fitted into Swindon No.1 boiler. Improvements were subsequently made to the draughting on some engines, while others were fitted with hopper ashpans.
The first of the Modified Halls was outshopped from Swindon in 1944. It carried plain black livery and was unnamed. After the nationalisation or Britain's railways
in 1948 British Railways
continued construction of this Great Western class until 1950.
Some modified Halls were equipped with a flat, high-sided Hawksworth tenders. Once he became Chief Mechanical Engineer, many earlier locomotives also received these tenders so a Hawksworth tender does not necessarily mean a Hawksworth locomotive.
on various heritage railway
s. A seventh survivor is to be used as a donor for the Grange and County re-creation projects.
Great Western Railway
The Great Western Railway was a British railway company that linked London with the south-west and west of England and most of Wales. It was founded in 1833, received its enabling Act of Parliament in 1835 and ran its first trains in 1838...
(GWR) 6959 Class or Modified Hall Class is a class of 4-6-0
4-6-0
Under the Whyte notation for the classification of steam locomotives, 4-6-0 represents the wheel arrangement of four leading wheels on two axles in a leading truck, six powered and coupled driving wheels on three axles, and no trailing wheels. This wheel arrangement became the second-most popular...
steam locomotive
Steam locomotive
A steam locomotive is a railway locomotive that produces its power through a steam engine. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine...
. They were a development by Frederick Hawksworth
Frederick Hawksworth
Frederick W. Hawksworth , was Chief Mechanical Engineer of the Great Western Railway ....
of Charles Collett
Charles Collett
Charles Benjamin Collett was chief mechanical engineer of the Great Western Railway from 1922 to 1941. He designed the GWR's 4-6-0 Castle and King Class express passenger locomotives.-Career:...
's earlier Hall Class.
The Modified Halls marked the most radical change to Swindon Works
Swindon Works
Swindon railway works were built by the Great Western Railway in 1841 in Swindon in the English county of Wiltshire.-History:In 1835 Parliament approved the construction of a railway between London and Bristol. Its Chief Engineer was Isambard Kingdom Brunel.From 1836, Brunel had been buying...
' practice since Churchward
George Jackson Churchward
George Jackson Churchward CBE was Chief Mechanical Engineer of the Great Western Railway in the United Kingdom from 1902 to 1922.-Early career:...
's time as chief mechanical engineer
Chief Mechanical Engineer
Chief Mechanical Engineer and Locomotive Superintendent are titles applied by British, Australian, and New Zealand railway companies to the person ultimately responsible to the board of the company for the building and maintaining of the locomotives and rolling stock...
. Hawksworth's use of plate frame
Locomotive frame
A locomotive frame is the structure that forms the backbone of the railway locomotive, giving it strength and supporting the superstructure elements such as a cab, boiler or bodywork. The vast majority of locomotives have had a frame structure of some kind...
s throughout the design was a daring break with Churchward's practice. The cylinders were cast separately from the smokebox
Smokebox
A smokebox is one of the major basic parts of a Steam locomotive exhaust system. Smoke and hot gases pass from the firebox through tubes where they pass heat to the surrounding water in the boiler. The smoke then enters the smokebox, and is exhausted to the atmosphere through the chimney .To assist...
saddle and bolted to the frames on each side. A stiffening brace was inserted between the frames and extended to form the smokebox saddle. The exhaust pipes leading from the cylinders to the blastpipe
Blastpipe
The blastpipe is part of the exhaust system of a steam locomotive that discharges exhaust steam from the cylinders into the smokebox beneath the chimney in order to increase the draught through the fire.- History :...
were incorporated into this assembly.
Additionally Churchward's bar framed bogie
Bogie
A bogie is a wheeled wagon or trolley. In mechanics terms, a bogie is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed in place, as on a cargo truck, mounted on a swivel, as on a railway carriage/car or locomotive, or sprung as in the suspension of a caterpillar...
which had been adapted for the original Hall in 1924 was replaced by a plate frame structure with individual springing. There were changes too above the running board. Hawksworth decided that the declining quality of coal reaching Great Western depots necessitated a higher degree of superheating. A larger three-row superheater
Superheater
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...
and header regulator were fitted into Swindon No.1 boiler. Improvements were subsequently made to the draughting on some engines, while others were fitted with hopper ashpans.
The first of the Modified Halls was outshopped from Swindon in 1944. It carried plain black livery and was unnamed. After the nationalisation or Britain's railways
Transport Act 1947
The Transport Act 1947 is an Act of the Parliament of the United Kingdom. Under it the railways, long-distance road haulage and various other types of transport were acquired by the state and handed over to a new British Transport Commission for operation...
in 1948 British Railways
British Rail
British Railways , which from 1965 traded as British Rail, was the operator of most of the rail transport in Great Britain between 1948 and 1997. It was formed from the nationalisation of the "Big Four" British railway companies and lasted until the gradual privatisation of British Rail, in stages...
continued construction of this Great Western class until 1950.
Some modified Halls were equipped with a flat, high-sided Hawksworth tenders. Once he became Chief Mechanical Engineer, many earlier locomotives also received these tenders so a Hawksworth tender does not necessarily mean a Hawksworth locomotive.
Preservation
Six Modified Halls are preservedHistoric preservation
Historic preservation is an endeavor that seeks to preserve, conserve and protect buildings, objects, landscapes or other artifacts of historical significance...
on various heritage railway
Heritage railway
thumb|right|the Historical [[Khyber train safari|Khyber Railway]] goes through the [[Khyber Pass]], [[Pakistan]]A heritage railway , preserved railway , tourist railway , or tourist railroad is a railway that is run as a tourist attraction, in some cases by volunteers, and...
s. A seventh survivor is to be used as a donor for the Grange and County re-creation projects.