Class M became sub-class D17/1, and Class Q became sub-class D17/2. The most significant visual difference between the two sub-classes was the shape of the main frames. The D17/1 engines had a downward reverse curve in the top profile behind the smokebox.

The North Eastern Railway Class M1 (LNER Class D17/1) is a class of 4-4-0 steam locomotive, designed by Wilson Worsdell. 20 initial engines were built, then 30 further units were built, designated Class Q (LNER Class D17/2).

All of the D17 boilers were built with Ramsbottom safety valves, with the exception of the last batch of fourteen replacement boilers (built in 1927-9) which were fitted with Ross pop safety valves. Hence most of the D17s did not receive LNER-standard Ross pop valves, and the last D17 to be withdrawn (62111) still had Ramsbottom valves fitted.

The London and North Eastern Railway (LNER) Class B17, also known as "Sandringham" or "Footballer" class was a class of 4-6-0 steam locomotive designed by Nigel Gresley for hauling passenger services on the Great Eastern Main Line. In total 73 were built.

In order to indicate variations within a class, subclass numbers were issued, taking the form of a suffix to the main class number, e.g. 'D17/1'. New build and converted locomotives to LNER designs were allocated class numbers in appropriate gaps in the series.

The LNER 4-4-0 'American' Locomotives D1-D24. The 4-4-0 was introduced to Britain in the 1850s with outside cylinders. The inside cylinder form became the archetypical British express locomotive in the late 19th Century. When superseded by Atlantics or 4-6-0s the type was versatile enough to continue on secondary passenger duties in many areas.

This second volume on the LNER 4-4-0 locomotives describes the design, construction, history, operation and performance of the North Eastern, North British, Great North of Scotland and Gresley LNER built examples, classified by the LNER at the Grouping as classes, D17 - D24, D25 - D36, D38 - D48 and D49 respectively.

The North Eastern Railway Class M1 (LNER Class D17/1) is a class of 4-4-0 steam locomotive, designed by Wilson Worsdell. 20 initial engines were built, then 30 further units were built, designated Class Q (LNER Class D17/2).

Covers the design, history, and performance of LNER 4-4-0 locomotives from their creation to the 1960s.This second volume on the LNER 4-4-0 locomotives descr...

Class M1 (LNER D17) preserved by the National Railway Museum (NRM) seen here in the exhibition hall at 'Locomotion', Shildon - similarities to class O in lining evident. Pinterest