LNER Class A4
The Class A4 is a class of streamlined 4-6-2 steam locomotive designed by Nigel Gresley for the London and North Eastern Railway in 1935. Their streamlined design gave them high-speed capability as well as making them instantly recognisable, and one of the class, 4468 "Mallard", holds the world record as the fastest steam locomotive. Thirty-five of the class were built to haul express passenger trains on the East Coast Main Line route from London Kings Cross via York to Newcastle, and later via Newcastle to Edinburgh, Scotland. They remained in service on the East Coast Main Line until the early 1960s when they were replaced by Deltic diesel locomotives. Several A4s saw out their remaining days until 1966 in Scotland, particularly on the Aberdeen - Glasgow express trains, for which they were used to improve the timing from 3.5 to 3 hours.
History of rail transport in Great Britain to 1830
Trevithick built a third locomotive in 1808, "Catch Me Who Can", which ran on a temporary demonstration railway in Bloomsbury, London. Members of the public were able to ride behind at speeds up to . However, it again broke the rails and Trevithick was forced to abandon the demonstration after just two months.
The first commercially successful steam locomotive was the twin cylinder "Salamanca", built in 1812 by John Blenkinsop and Matthew Murray for the gauge Middleton Railway. Blenkinsop believed that a locomotive light enough to move under its own power would be too light to generate sufficient adhesion, so he designed a rack and pinion system for the line. This was despite the fact that Trevithick had demonstrated successful adhesion locomotives a decade before. The single rack ran outside the narrow gauge edge-rail tracks and was engaged by a cog-wheel on the left side of the locomotive. The cog-wheel was driven by two cylinders embedded into the top of the center-flue boiler. Four such locomotives were built for the railway, and they worked until the early 1830s.