North Eastern Railway (UK) Worsdell rebuilt Fletcher 2-2-4T locomotive number 66 Aerolite

on display in the great hall at the National Railway Museum, York. Monday 1st June 2009.


In Whyte notation, a 2-2-4T is a steam locomotive that has two leading wheels followed by two coupled driving wheels and four trailing wheels. This was an unusual wheel arrangement, only used on a few specialiZed locomotives. This wheel arrangement is only used for tank locomotives.


Schematic of 2-2-4 steam locomotive wheel arrangement. Front of locomotive on left.

(Gwernol, Public domain, via Wikimedia Commons)


Equivalent classifications

Other equivalent classifications are:

  • UIC classification: 1A2 (also known as German classification and Italian classification)
  • French classification: 112
  • Turkish classification: 14
  • Swiss classification: 1/4


UK examples

In the United Kingdom (No U.S. examples are known), the North Eastern Railway, had four tank locomotives of this wheel arrangement, all of which had previously been rebuilt from other types. They were: No. 66 Aerolite rebuilt as a 2-2-4T in 1902 and later known as in LNER class X1; No. 957, which had been rebuilt from a BTP class 0-4-4T in 1903 and later classified as X2 class. NER 190 Class, later class X3 had two members, Nos. 190 and 1679, both rebuilt from 2-2-2 tender locomotives. All four were inherited by the London and North Eastern Railway (LNER) at the time of its formation on 1 January 1923, and withdrawn from service between 1931 and 1937. No. 66 Aerolite has been preserved at the National Railway Museum in York.