the same piston stroke and driving wheel diameter, which gave both locomotives the same piston speed for the same track speed. 1948 Locomotive Exchange Trials In 1948, shortly after the formation of British Railways, the decision was taken to test locomotives from all of the former 'Big Four' companies to find the best attributes of speed, power and efficiency with coal and water. There were two ways of testing and comparing locomotives: either at the Rugby Locomotive Testing Station, which was not ready until late 1948 or by testing in the field itself. The results of the 1948 Locomotive Exchange Trials would be used to help design the British Railways Standard locomotives. The express passenger locomotive designs which would be compared were: London Midland Region (former LMS) Princess Coronation class, Eastern Region (former LNER) Class A4, Southern Region (former Southern) Merchant Navy class and Western Region (former GWR) King class. Three Gresley A4 locomotives were chosen to represent the Eastern Region: E22 Mallard, 60033 Seagull and 60034 Lord Faringdon. All of the locomotives had the Kylchap double blastpipe chimney arrangement and were fresh from Doncaster works. Mallard had emerged from Doncaster with a fresh coat of post-war garter blue livery, stainless steel numbers 22 with a small 'E' painted above them (for Eastern region), new boiler (its fourth) and third tender of its career. E22 Mallard was used on 8 June 1948 on the London Waterloo to Exeter route. Driver Marrable took the famous A4 with a load of 481 tons tare, 505 tons full, the same that had been used on the previous trip by 35018 British India Line. Mallard reached Clapham Junction in 6 minutes 57 seconds and Woking in 28 minutes 47 seconds. At Hook there were adverse signals, causing Mallard to slow to a crawl. Even so, Salisbury was reached in 108 minutes and 28 seconds. Despite the signals earlier, the train was only 5-and-a-half minutes late. The net time was 95.5 minutes. Mallard failed after this trial and 60033 Seagull took over. On 10 June Seagull achieved the run in 96 minutes 22 seconds, but had departed 3 minutes late, meaning Seagull had arrived with the same load 3.5 minutes early. For Mallard, the trials were over, but Mallard returned to the Waterloo-Exeter line for a Locomotive Club of Great Britain (LCGB) railtour on 24 February 1963. The Elizabethan The Elizabethan Express was a flagship