The LNER Singles: 2-2-4 and 4-2-2 Locomotives

The LNER used the designation "X" for all of the single-driver locomotives that it inherited. These had 4-2-2 and 2-2-4T wheel arrangements. the two types of single-driver locomotives which it inherited. Three types (X1, X2, and X3) of 2-2-4T tank engines came from the North Eastern Railway (NER) and were used to pull inspection saloons for railway officials. The other type, was that of the X4 4-2-2 tender locomotive came from the Great Central Railway (GCR).

4-2-2 Tender Locomotives

Although single driver express locomotives fell out of favour long before Grouping (1923), the concept had a short-lived resurgence in the late 19th Century with the invention of steam sanding gear. Six such locomotives were inherited from the GCR.

2-2-4 Tank Locomotives

The LNER also inherited four 2-2-4T tank engines from the NER. All four tanks had complex histories and owed their survival to specialised use hauling inspectors' saloons.