In 1952 London Transport, in order to relieve the pressure on its Chiswick bus overhaul works, began converting and extending an existing building at Aldenham near Elstree in Hertfordshire on a site originally intended for car sheds for the proposed Northern Line Bushey Heath extension. Work on engines and gearboxes, experimental work and chassis overhauls continued at Chiswick until 1955 when all overhaul work was transferred to Aldenham, which was officially opened in October 1956. The site was at its busiest during the late 1950s and early 1960s. Work carried out included body rebuilds, accident repairs, repaints, seat trimming, destination blinds, new bus preparation and tilt-testing.
London Transport's Bus Works Restructuring Programme of 1983-1984 was followed in October 1985 by the decision to discontinue the practice of completely overhauling each bus every four or five years. As a result, the Aldenham Works were closed and sold for redevelopment in November 1986 and its activities were transferred to the older and smaller maintenance depot at Chiswick.
Reference: G.J. Child, 'Aldenham Bus Works', Journal of the Watford and District Industrial History Society, no.15, pp.15-17. 1989; Transport for London Corporate Archives research guide no 33, Apr 2016 (http://content.tfl.gov.uk/research-guide-no-33-aldenham-bus-works.pdf).