London Underground D78 Stock London Underground D78 Stock The London Underground D78 Stock, commonly referred to as D Stock, was a type of sub-surface rolling stock which operated on the District line of the London Underground, except on the Wimbledon to Edgware Road service. Following the withdrawal of the C Stock in June 2014, these were the oldest subsurface trains in service on the London Underground. The first units were withdrawn in January 2015 with the last withdrawn on 21 April 2017. The D stock was ordered in 1976 to replace the pre-war CO/CP Stock and post-war R Stock on the District line. Seventy-five
London Underground engineering stock London Underground engineering stock Over the years, London Underground has acquired various types of engineering stock to help with the construction of new lines and maintenance of existing lines. Some of these wagons were inherited from its predecessors, many were built new and some were acquired second-hand from the main-line railways. Several types of specialist wagons have been used, which are described below. London Underground uses a numbering system comprising the wagon number prefixed with a letter which designates the wagon's type. These are summarised below. London Underground has used various designs of brake van. They were used for the