The GWR 645 Class was a class of designed by George Armstrong and built at the

Wolverhampton railway works Wolverhampton railway works was in the city of Wolverhampton in the county of Staffordshire, England. It was almost due north of the city centre, and is commemorated with a small display of level crossing gates and a plaque. Known as the Staf ...

of the

Great Western Railway The Great Western Railway (GWR) was a British railway company that linked London with the southwest, west and West Midlands of England and most of Wales. It was founded in 1833, received its enabling Act of Parliament on 31 August 1835 and ran ...

(GWR). Thirty-six were constructed between 1872-3, of which three were built for the

South Wales Mineral Railway The South Wales Mineral Railway was a railway built to serve collieries in the upper Afan Valley, and bring their output to a dock at Briton Ferry, in South Wales. It opened in stages, in 1861 and 1863. It was built on the broad gauge and had ste ...

(SWMR), two for the

Carmarthen and Cardigan Railway The Carmarthen and Cardigan Railway was a broad gauge railway line in Wales that was intended to connect Carmarthen on the South Wales Railway with Cardigan. In fact, it was unable to raise the necessary capital and was loss-making from the tim ...

(C&CR) and the remainder for the GWR. In essence, they were saddle tank versions of his GWR 633 Class of 1871. From 1878, a further 72 of the class, partially enlarged, were added in the 1501 numbering sequence. Unlike the originals, the "1501"s had full-length saddle tanks from the start.

Construction

The whole class was delivered in nine lots, as follows: * 645-655, plus one (Lot O, 1872) * 656, 757-763, plus four (Lot P, 1872-3) * 764-775 (Lot Q, 1873) * 1501-1512 (Lot A2, 1878) * 1513-1524 (Lot B2, 1878-9) * 1525-1536 (Lot D2, 1879) * 1537-1548 (Lot E2, 1879–80) * 1549-60 (Lot F2, 1880) * 1801-1812 (Lot G2, 1881) Three of the un-numbered engines plus No. 767 were sold to the SWMR, and the other two plus No. 655 to the C&CR. The latter three returned to the GWR in 1881, becoming Nos. 902-904.

Dimensions

When built, they had

driving wheel On a steam locomotive, a driving wheel is a powered wheel which is driven by the locomotive's pistons (or turbine, in the case of a steam turbine locomotive). On a conventional, non-articulated locomotive, the driving wheels are all coupled ...

s (later due to thicker

tyres A tire (American English) or tyre (British English) is a ring-shaped component that surrounds a wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide traction on the surface over which t ...

) and , or

cylinders A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an in ...

. Half-cabs were added a few years after construction. From 1918 all but eight of the class were rebuilt with Belpaire fireboxes and larger, pannier tanks extending over the

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 e ...

, and the

diameter In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It can also be defined as the longest chord of the circle. Both definitions are also valid f ...

cylinders became standard.

Use

Most of the 645s and 1501s were allocated to the Northern Division of the GWR. Between 1910 and 1922 three more of them, Nos. 1806, 1811 and 1546, were transferred to the SWMR, and others too went to South Wales. Most were withdrawn in 1930s. Nos. 1531, 1532, 1538 and 1542 passed briefly 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 ...

ownership, but all were withdrawn by December 1949. None have survived into preservation.

References

* * {{GWR Locomotives 0645 0-6-0ST locomotives Railway locomotives introduced in 1872 Scrapped locomotives Mixed traffic locomotives

Construction

Dimensions

Use

See also

References