Nigel Gresley
Sir Herbert Nigel Gresley (19 June 1876 – 5 April 1941) was an English railway engineer. He was one of Britain's most famous steam locomotive engineers, who rose to become Chief Mechanical Engineer (CME) of the London and North Eastern Railway (LNER). He was the designer of some of the most famous steam locomotives in Britain, including the LNER Class A1 and LNER Class A4 4-6-2 Pacific engines. An A1 Pacific, "Flying Scotsman", was the first steam locomotive officially recorded over 100 mph in passenger service, and an A4, number 4468 "Mallard", still holds the record for being the fastest steam locomotive in the world (126 mph).
VR Class Dr12
When it was introduced, the Dr12 gave drivers a new experience of comfort and forward visibility compared to steam locomotives, but compared to the newer VR Class Dr13, the Dr12 had a heavy axle load and slow acceleration with a top speed of only 120 km/h. The reason for this was that the locomotive turned out to be underpowered. The problem of the top speed was corrected in the last 10 locomotives by changing the transmission in such a way that the technical top speed was increased to 140 km/h, but this feature was never used. As a result, the entire locomotive series had a maximum permissible speed restricted to 120 km/h. However, due to the high axle weight, the Dr12 had good adhesion properties and it was considered to be a reliable and robust locomotive. It was well-suited to heavy trains with relatively low speed requirements.