District line Railway (L&SWR), and branches reached Ealing Broadway, Hounslow and Wimbledon. As part of the project that completed the Circle line in October 1884, the District began to serve Whitechapel. Services began running to Upminster in 1902, after a link to the London, Tilbury & Southend Railway (LT&SR) had been built. At the start of the 20th century the District was seeing increased competition from the new electric underground tube lines and trams, and the use of steam locomotives underground led to unpopular smoke-filled stations and carriages. The American Charles Yerkes, who was later to form the Underground Electric Railways of
London Underground Standard Stock and were later reclassified to become Classes 485 and 486. Apart from those cut up following accidents at Ryde depot, and other early withdrawals, most of these units were withdrawn between 1988 and 1991, when they were replaced by London Underground 1938 Stock. In October 1990, five cars were returned to London Transport, to form a Heritage Train. They worked under their own power between Fratton and Wimbledon, and were displayed at an open day at Morden Depot, celebrating 100 years of the Northern line. Standard Stock is used to describe six experimental cars built by five manufacturers in 1923,