The decision to find out how fast the locomotive could run with the seven-vehicle load seems to have been almost a spur of the moment decision, and it is notable that no-one from the LNER Magazine was aboard, leaving the publication to reproduce an account from the Railway Gazette.
Mallard took her carriages through Grantham station at just 24mph because of permanent way work, and then accelerated to almost 60mph over the next two and a half miles up a rising gradient of 1 in 200, eventually reaching almost 75mph over the next mile-and-a-half to Stoke summit, again over a further stretch at 1 in 200. Descending Stoke Bank, the speed rose to 116mph, and then to 119mph, and then crossed the 120mph mark where it stayed for the next three miles, reaching a maximum of 126mph. The locomotive maintained a speed of between 123mph and 126mph for nearly two miles. The record-breaking run was then curtailed as the opportunity was taken to conduct a brake test from such a high speed and the train was approaching the curve at Essendine, which also included several sets of points, and it was thought unwise to take these at such a high speed.
This was a greater achievement than generally realised, not just because it has never been beaten anywhere, but because far from being specially prepared, Mallard had worn valves and was driven hard by a driver, Driver J, Duddington of Doncaster, known for thrashing his locomotives. Had she been properly prepared and all valve clearances correct, the record might have been set even higher. As it was, those on the footplate could smell the machinery at is overheated and the locomotive needed major workshop attention afterwards.
Many claim that the locomotives of the day operating in the United States and Germany could have matched or even exceeded this record, but the point is that they didn’t. One would have expected the Germans, whose dictator had a thirst for propaganda, to have set a new record if they had been able. Others have also suggested that the LMS ‘Duchess’ class could have matched or exceeded the record, but again, this did not happen. It might be pertinent to note that while the LNER cut the London to Edinburgh journey time of the Flying Scotsman to just six hours, the rival LMS service to Glasgow took 30 minutes longer.
Extracted from The LNER Handbook by David Wragg
Mallard retired from service in 1963 and was subsequently preserved in 1964 by the British Transport Commission. In 1975 Mallard entered the National Railway Museum’s collection in York. It was restored to working order between 1982 and 1988 and completed a limited number of runs until 1989. It is now one of only six remaining A4 Pacifics. In 2013, to celebrate the 75th anniversary of Mallard’s speed record, all six locomotives were reunited at the National Railway Museum. On the weekend of 5 July 2008, Mallard was taken outside for the first time in years and displayed beside the three other A4s that are resident in the UK, thus reuniting them for the first time since preservation. It departed the museum for Locomotion, the National Railway Museum’s outbase at Shildon in June 2010, where it was a static exhibit, until it was hauled back to York in July 2011 and put back on display in its original location in the Great Hall. Today Mallard remains one of the highlights of the museum.