Czech rail records
The fastest steam locomotive
Locomotive 498.106 ČSD, nicknamed Albatross, reached top speed 162 km/h on railway test circuit Velim (August 27, 1964)
LNER Class A4 4468 Mallard
"Mallard"s world record has never been officially exceeded by a steam locomotive, though the German Class 05 was at least very close: in 1936, two years before "Mallard"s run, 05 002 had reached 200.4 km/h (124.5 mph) between Hamburg and Berlin. Stoke Bank is long, straight and slightly downhill, whereas the 1936 run of 05 002 took place on a horizontal stretch of track. Unlike world records for cars and aircraft, there is no requirement for an average of two runs in both directions, and assistance from gradient or wind has always been acceptable in rail speed records. Also, unlike "Mallard", 05 002 survived the attempt undamaged: on the other hand, its train was only four coaches long (197 tons), whereas "Mallard"s train was seven coaches (240 tons). In terms of rival claims, Gresley and the LNER had just one serious attempt at the record, which was far from a perfect run with a permanent way check just North of Grantham. Despite this a record was set. Gresley planned to have another attempt in September 1939, but this was prevented by the outbreak of World War II. Before the record run on 3 July 1938, it was calculated that was possible, and in fact Driver Duddington and LNER Inspector Sid Jenkins both said they might well have achieved this figure had they not had to slow for the Essendine junctions. There are claims that the Milwaukee Road class F7 and PRR S1 locomotives attained service speeds faster than "Mallard"'s record. However, such claims were not officially verified, thus "Mallard" continues to hold the official record. The LNER A4 and PRR T1 classes had the same piston stroke and driving wheel diameter, which gave both locomotives the same piston speed for the same track speed.
Thus, "Mallard" still officially holds the record; plaques affixed to each side of the locomotive commemorate the feat. The plaques were proposed and designed by Morley headmaster Harry Underwood, a keen steam enthusiast, in 1948.