LNER Class A4 - Performance in Service

Performance in Service

No other British steam locomotives have a longer or more consistent record of high speed running than the A4s, instances of 100 mph running by them must exceed those of all other types combined, though it must be stressed that even 90 mph running was a relatively rare event with steam traction, much less 100 mph. It should also be remembered that A4s operated on the East Coast Main Line which has more opportunities for high speed running (particularly Stoke Bank) than any other in the UK.

In August 1936 the Silver Jubilee train on the descent of Stoke Bank headed by 2512 Silver Fox driven by George Henry Haygreen achieved a maximum of 113 mph (181.9 km/h), then the highest speed attained in Britain with an ordinary passenger train. The fastest recorded post war speed with British steam was also recorded by an A4. This occurred on the 23 May 1959 on the Stephenson Locomotive Society Golden Jubilee special when 60007 achieved 112 mph whilst hauling 400 tons down Stoke Bank. The driver was Bill Hoole and he had hoped for an attempt to beat Mallard's record but Alan Pegler, who was on the footplate and mindful of the risks, told him to ease off.

Although A4s were primarily designed for high speed express work they were also capable of high power outputs. In 1940 Capercaillie (4901) exerted 2200 drawbar horse power on the level York plain whilst hauling 21 coaches (730 tons gross) at an average of 75.9 mph for 25 miles. The highest recorded power output from an A4 was 2450 drawbar horspower when Mallard herself was hauling 11 coaches (390 tons gross) up Stoke Bank at a sustained 80 mph in 1963. O.S. Nock thought this performance superior to Mallard's world record run in 1938. To put all this in perspective the highest possible drawbar horsepower from a Class 40 diesel, which were supposed to replace the A4s, was 1450, though they could achieve this figure over long distances and with no effort from the crew.