asterisk were fitted with a boiler which had the top feed on the front ring on the date shown. In the case of no. 45087 it had previously been converted. The first conversion was carried out on no. 5022, and the last known was on no. 45163, which has been preserved. 5002 (12/37), 45007 (1/60), 45008 (1/60*), 45011 (1/49*+), 5020 (2/37), 5022 (10/36) reverted (10/58), 5023 (2/38) reverted (3/53), 5026 (2/37) reverted (1/59), 5027 (12/36), 5040 (11/36), 5045 (11/54), 5047 (1/37), 45049 (7/54) reverted (8/59), 5054 (1/37), 5057 (11/37), 5058 (11/37), 5059 (7/45), 45066 (4/60), 45082 (12/56*), 45087 (9/55) (12/60*), 5097 (1/37), 5108 (6/45), 45109 (5/48), 5142 (12/37), 45151 (3/51), 45163 (5/61), 45169 (7/55), 45197 (5/60) + The subsequent history of 45011 is not clear. Official records have gone missing and have not been relocated. There is a photograph in existence dated April 1963, showing 45011 ex-works with a straight throatplate boiler and simple top feed, i.e. without the dome-like shape. NB: The official records were not always updated after around 1960/61, although some were. For example, in the case of no. 45082, it was fitted with a brand new boiler at the end of 1956, one of the last batch of four boilers that were manufactured for this class. Since it survived in service for a further nine and a half years, there is no doubt that 45082 will have had at least one further boiler lift and indeed a photograph exists of it at Hellifield with a given date of May 1962 showing it with an older boiler with the dome and feed both on the tapered ring. Unfortunately it is not clear from the photo whether it is a straight or sloping throatplate boiler. The pre-war domed engines A further 227 were ordered from Armstrong-Whitworth in 1936, the largest single locomotive order ever given by a British railway to an outside contractor. Crewe built a further 20, which had higher degree superheat boilers, with 28 elements, unlike the AW boilers, which had 24 elements. 5471, built at Crewe in 1938, would be the last built for five years. During the early stages of the Second World War, the priority was for heavy freight engines, and the closely related 8Fs were produced in large numbers. Wartime and postwar domed engines In 1943 construction was restarted, with Derby Works building its first. Construction continued up to no. 5499. As