London Underground D78 Stock total of five 3-car sets, to be built as BMMUs, in June 2018. 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 The first units were withdrawn in January 2015 with the last withdrawn on 21 April 2017.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
History of the London Underground half of the 19th century, London had grown greatly and the development of a commuting population arriving by train each day led to traffic congestion with carts, cabs and omnibuses filling the roads. By 1850 there were seven railway termini located around the urban centre of London and the concept of an underground railway linking the City of London with these stations was first proposed in the 1830s. Charles Pearson, Solicitor to the City of London, was a leading promoter of several schemes, and he contributed to the creation of the City Terminus Company to build such a railway from