Record
Mallard is the holder of the official world speed record for steam locomotives at 125.88 mph (202.58 km/h). The record was achieved on 3 July 1938 on the slight downward grade of Stoke Bank south of Grantham on the East Coast Main Line, and the highest speed was recorded at milepost 90¼, between Little Bytham and Essendine. It broke the German (DRG Class 05) 002's 1936 record of 124.5 mph (200.4 km/h).
Mallard was the perfect vehicle for such an endeavour; one of the A4 class of streamlined locomotives designed for sustained 100+ mph (160+ km/h) running, it was one of a small number built with a double chimney and double Kylchap blastpipe, which made for improved draughting and better exhaust flow at speed; the remainder of the class were retro-fitted in the late 1950s. The A4's three-cylinder design made for stability at speed, and the large 6 ft 8 in (2.03 m) driving wheels meant that the maximum revolutions per minute was within the capabilities of the technology of the day. Mallard was five months old, meaning that it was sufficiently broken-in to run freely, but not overly worn. Selected to crew the locomotive on its record attempt were driver Joseph Duddington (a man renowned within the LNER for taking calculated risks) and fireman Thomas Bray.
The locomotive had previously had problems with the big end bearing for the middle cylinder, so a "stink bomb" of aniseed oil was placed inside the big end, that would be released if it overheated. Shortly after the attainment of this record speed, Mallard suffered an overheated middle big end and had to limp onwards to Peterborough after setting the record. It then travelled to Doncaster for repair. This had been foreseen by the publicity department, who had many pictures taken for the press, in case Mallard did not make it back to Kings Cross. The (Edwardian period) Ivatt Atlantic that replaced Mallard at Peterborough was only just in sight when the head of publicity started handing out the pictures. Inaccuracies in the machining and setup of the Gresley-Holcroft derived motion (which derived the valve motion of the inside (middle) cylinder from those of the other two, avoiding a hard-to-maintain valve gear linkage between the frames) meant that the inside cylinder of the A4 did more work at high speed than the two outside cylinders; this overloading was mostly responsible for the failure.
Stoke Bank had a descending gradient of between 1:178 and 1:200. Mallard, with six coaches plus a dynamometer car in tow, topped Stoke Summit at 75 mph (121 km/h) and began to accelerate downhill. The speeds at the end of each mile (1.6 km) from the summit were recorded at: 87½, 96½, 104, 107, 111½, 116 and 119 mph (141, 155, 167, 172, 179, 187 and 192 km/h); half-mile (800 m) readings after that gave 120¾, 122½, 123, 124¼ and finally 125 mph (194, 197, 198, 200 and 201 km/h). The speed recorded by instruments in the dynamometer car reached a momentary maximum of 126 mph (203 km/h).
On arrival at King`s Cross (just after the run) driver Joe Duddington and Inspector Sid Jenkins were quoted as saying that they thought a speed of 130 mph would have been possible if the train hadn`t had to slow for the junctions at Essendine. In addition at the time of the run there were permanent way restriction to 15 mph just north of Grantham which slowed the train as they sought to build up maximum speed before reaching the high speed downhill section just beyond Stoke tunnel.
Read more about this topic: LNER Class A4 4468 Mallard
Famous quotes containing the word record:
“The house seems heavier
Now that they have gone away.
In fact it emptied in record time.”
—John Ashbery (b. 1927)
“Death is another milestone on their way.
With laughter on their lips and with winds blowing round them
They record simply
How this one excelled all others in making driving belts.”
—Stephen Spender (1909–1995)
“That is what the highest criticism really is, the record of one’s own soul. It is more fascinating than history, as it is concerned simply with oneself. It is more delightful than philosophy, as its subject is concrete and not abstract, real and not vague. It is the only civilised form of autobiography.”
—Oscar Wilde (1854–1900)