The London and North Eastern Railway Gresley Classes A1 and A3 locomotives represented two distinct stages in the history of the British 4-6-2 "Pacific" steam locomotives designed by Nigel Gresley.

Below are the names and numbers of the steam locomotives that comprised the LNER Gresley Classes A1 and A3, that ran on the Great Northern (GNR) and latterly the London and North Eastern Railway network.

The A3 was a modification of the original A1 design, and all of the surviving A1s were eventually rebuilt as A3s. Thompson designated the remaining members of the A1 class awaiting rebuilding as the A10 Class.

From 1928, the A1s started being fitted with higher-pressure superheated boilers. This reboilering turned them into Class A3, and eventually all but one A1 would be rebuilt to A3s up to 1948. In addition, 27 new A3s (Nos 2743-2752, 2595-2599, 2500-2508, 2795-2797) were built.

Mar 6, 2022 · The A1s and A3s hauled the principal express services on the East Coast Main Line, from London to Leeds, York, Newcastle upon Tyne, Edinburgh and Glasgow, from the mid 1920s to the late 1950s.

Jun 14, 2015 · The A3 was a modification of the original A1 design, and all of the surviving A1s were eventually rebuilt as A3s. Thompson designated the remaining members of the A1 class awaiting rebuilding as the A10 Class.... ...Locomotives with the boiler rebuild were given the designation of Class A3.

Jun 15, 2018 · The main difference between the two classes was the boiler pressure, 180psi for the A1s, 220psi for the A3s. This lead to an increase in tractive effort from 29,835 lbf to 36,465 lbf (When both classes had 20in by 26in cylinders).

The London and North Eastern Railway LNER Gresley Classes A1 and A3 locomotives represented two distinct stages in the history of the British 4-6-2 "Pacific" steam locomotives designed by Nigel Gresley.

The London and North Eastern Railway Gresley Classes A1 and A3 locomotives represented two distinct stages in the history of the British 4-6-2 "Pacific" steam locomotives designed by Nigel Gresley. They were designed for main line passenger …

The London and North Eastern Railway LNER Gresley Classes A1 and A3 locomotives represented two distinct stages in the history of the British 4-6-2 "Pacific" steam locomotives designed by Nigel Gresley.