GWR 3800 Class - Operation

Operation

They were the last new GWR 4-4-0 design and by far the most modern, with inside frames and outside cylinders. They were designed as a part of Churchward's standardisation plan, but were found to have a front end too powerful for the wheel arrangement and all were withdrawn by the early 1930s. They were designed, in part, for the Hereford to Shrewsbury LNWR line over which the GWR had running powers, but on which they were expressly forbidden to use 4-6-0 locomotives. The 4-4-0 Counties were in effect a shortened GWR 2900 Class, providing engines powerful enough for the trains but with the requisite four coupled wheels.

The key components were all proven but the combination was somewhat unhappy, and perhaps the least successful Churchward design. From the outset they were found to be rough riders but otherwise effective locos. All other GWR 4-4-0's were inside cylindered and none had a piston stroke greater than 26", whereas the 'County' had a 30" stroke driving a meagre 8' 6" wheelbase.

The County Class used the same cylinders and motion as Churchward's six-coupled locomotives, and required the same mass to counterbalance the reciprocating parts of the motion. However the weight required had to be divided between four driving wheels rather than six. The heavier balance weights produced a high level of wheel hammer blow; at 6 revolutions per second the hammer blow was 8 tons, compared with the 3.6 tons of the inside-cylindered City Class and the 6.4 tons of the six-coupled Saint Class. The left hand trailing axleboxes often developed hammering, which was caused by the amount of counterbalancing used.

This class were subject to the 1912 renumbering of GWR 4-4-0 locomotives, which saw the Bulldog class gathered together in the series 3300-3455, and other types renumbered out of that series. The County Class took numbers 3800-3839.

No. 3833 County of Dorset was the first to be withdrawn, in February 1930. By the middle of 1933 all had gone, the last survivor being no. 3834 County of Somerset, withdrawn in November of that year.

They were also the basis for the 'County Tank' design, a 4-4-2T using the same basic design as the County but with a smaller and lighter boiler, and the replacement of the tender by the addition of side tanks, bunker and trailing axle.