express that ran non-stop over the between London King's Cross and Edinburgh Waverley from 1953 to the mid-1960s. Until September 1961 it was steam-hauled. In its day it was the longest non-stop run in the world. Two crews were needed for the six-and-a-half-hour run. They were able to change over mid-journey by using a corridor tender. Only a few locomotives other than Mallard had such a tender. In December 1961, Mallard hauled the final steam-hauled northbound Elizabethan train. Preservation Following the introduction of diesel and electric trains, many steam locomotives across the UK were set to be scrapped. In December 1960, a notification was issued to have Mallard preserved, which was not confirmed until 29 August 1962. Its final revenue earning service took place on 25 April 1963, after which the locomotive was sent to Doncaster Works for repair and restored to its original condition. In February 1963, Mallard was sent to Nine Elms depot, followed by the Museum of British Transport museum in Clapham, south London. It then ran a series of special trains, including a run from Doncaster via Nottingham Victoria to Clapham Junction. Following a relaxation of the ban on steam locomotives in the UK in the 1970s, Mallard hauled a train from Stewarts Lane, Battersea to York via the Midland Main Line in on 12 April 1975 in preparation for the opening of the National Railway Museum, where it remained. This was followed by periods on display at York and Doncaster Works in June 1977 and June 1978, respectively. In the 1980s, Mallard was restored to working order to commemorate the 50th anniversary of its 1938 record speed run. Its first run took place on 26 March 1986 from York to Doncaster, and a series of other special trains were completed across England in 1986 through 1987. The locomotive's final run in operation was on 3 July 1988 from Doncaster to Scarborough and back, which was attended by several family members of the original train crew on the 3 July 1938 run. The trip was related to a special commemorative postage stamp featuring Mallard. In July 2003, Mallard was put on display outside the National Railway Museum as part of the 150th anniversary of Doncaster Works. It was taken outside again in July 2008 beside three other preserved A4s located in the UK, thus reuniting them for the first time since preservation. In 2012, six preserved