The dog chart and associated locking table, derived from the dog chart, show the position as at 23 December 1946. In 1930, East and West boxes had been replaced by a single, central box. The locking chart is marked up to show electric locks (with lever normal contacts) provided on levers 2, 7, 64 and 70 and a reverse lock provided on FPL lever 35. Note that although both FPL levers (24 and 35) are now provided with reverse locks, the each way locking has not yet been removed. A contemporary box diagram may be consulted in the publication 'An Historical Survey of Selected Great Western Stations Volume 4, OPC, page 164'.
In 1955, crossover 26 and associated discs 25 and 27 were removed and the locking alterations are shown in the dog chart and associated locking table, derived from the dog chart, at amendment A, dated September 1955.