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.

London and North Eastern Railway's (LNER) Peppercorn Class A1 is a class of 4-6-2 "Pacific" steam locomotives largely built between 1948 and 1949 at Doncaster and Darlington Works to a design of Arthur Peppercorn.

The Peppercorn A1 Pacifics. The fast A1 class was an important part of Thompson's standardisation scheme, but most of his Pacific development efforts went towards the A2/3 (and related rebuilds) before he retired in 1946. In fact, the only A1 built during his tenure was the prototype rebuild of A1/1 Great Northern.

In 1923, the LNER inherited four pacifics, to two classes each consisting of two locomotives, one class from either of two of its constituents, the Great Northern Railway (GNR) and the North Eastern Railway (NER). The Great Northern Pacifics, were of GNR Class A1, designed by Nigel Gresley and numbered 1470/1.

The LNER A1 and A3 Gresley Pacifics. Gresley is most famous for his LNER Pacifics. Although they reached their peak with the streamlined A4s, this famous line of 'racehorses' began with the A1 Pacifics. The first two A1 Pacifics were built in the twilight years of the Great Northern Railway (GNR) and entered service in 1922.

“Peppercorn”A1型机车旨在应对战后运行于英国“东海岸主线”——伦敦国王十字—爱丁堡威瓦利铁路上的旅客列车，这些旅客列车通常编组最多15节车厢，重量达到550 t。“Peppercorn”A1型机车能够以95 km/h~110 km/h的速度在平道上牵引这样的旅客列车。

All the names, numbers and photos of class A1 LNER "Pacifics" (4-6-2 wheel arrangement) as designed by A.H.Peppercorn. The numbers are those carried by the locomotives in the BR period. The class was 49 strong as built in the late 1940's but this number has now increased to 50 thanks to the new build 60163 Tornado.

The Thompson A1/1 Pacific. Thompson initially worked on producing a mixed-traffic Pacific, before working on a new express passenger design. With the intention of improving the A4 design, Thompson drew up two modified Gresley 3-cylinder designs. These designs discarded the conjugated gear and had separate sets of Walschaerts valve gear for each ...

The London and North Eastern Railway (LNER) Peppercorn Class A1 is a type of express passenger steam locomotive. Forty-nine Peppercorn Class A1s were built to the design of Arthur Peppercorn (who was the last Chief Mechanical Engineer (CME) of the LNER during the early British Railways era.

The Peppercorn Class A1 was designed by the last London & North Eastern Railway (LNER) Chief Mechanical Engineer, Arthur Peppercorn, who develpoped the designs for new A1 locomotives from Edward Thompson, as an evolution in LNER Pacific locomotive design, initiated by Nigel Gresley in 1922 with his original A1 Class (later rebuilt as A3 Class ...