GCR Class 8F
The GCR Class 8F was a class of ten 4-6-0 locomotives built for the Great Central Railway in 1906 by Beyer, Peacock and Company to the design of John G. Robinson for working fast goods and fish trains. They passed to the London and North Eastern Railway at the 1923 grouping and received the classification 'B4'.
Design
These engines were very similar to two locomotives of an earlier 4-6-0 type the GCR had except that they had smaller driving wheels.They were built with a saturated boiler, inside slide valves and Stephenson valve gear, two outside cylinders connected to diameter driving wheels.
LNER ownership
The ten locomotives were renumbered by the LNER by adding 5000 to their GCR numbers; and classified as B4.Modifications
Between 1925 and 1928 the whole class received superheated boilers, but six received 10-inch piston valves and 21-inch cylinders giving rise to two LNER sub-classes B4/1 and B4/2.The LNER had designed a new type of superheated boiler based on the old design. These were used on the B1 and B4 class locomotives; no more of this type of boiler was made after 1932, and so to keep the B1 and B4s in service during World War II, some Diagram 15 boilers were modified for use with these locomotives.