Upminster station had been extensively improved in the early 1930s with a new bay for the Grays branch trains and an additional island platform. A large amount of remodelling was done in 1957 to separate the British Railways and London Transport tracks. An additional platform, No. 6, was built for the Romford trains, where the Derby Lightweight DMU is standing on the day it was opened, 20th July 1957. A contingent of PW workers appear to be putting the finishing touches to the trackwork as the unit is signalled to leave for Romford. Platforms 3, 4 and 5 were used by the London Transport District line trains.