The dog chart and associated locking table, derived from the dog chart, show the position as at 7 February 1950. The locking frame was converted to VT 5 bar and renumbered to 84 levers in July 1948 and track circuit 68T was added in February 1950. A contemporary box diagram may be consulted in the publication 'Signal Box Diagrams of the GW and SR by G.A.Pryer, volume 20, GWR Berks and Hants lines'.