Class D49

The London and North Eastern Railway class D49 is a class of 4-4-0 steam locomotives designed by Nigel Gresley in 1927 for intermediate express duties.

The London and North Eastern Railway class D49 is a class of 4-4-0 steam locomotives designed by Nigel Gresley in 1927 for intermediate express duties. The class D49/1s were named after Shire counties, and the D49/2s were named after fox hunts. A total of 76 class class D49s in three main variants were built between 1927 and 1935.

The class D49 had to replace aging North Eastern Railway (NER) and North British Railway (NBR) locomotives, and to supplement the use of existing NER and NBR Atlantics on the various routes that the new class A1s were restricted from. Hence it had to be powerful for its size, and Gresley chose to use a three-cylinder arrangement using his patented conjugated valve gear.

Economic considerations led to the use of the same boiler design as that used on the successful class J39 0-6-0 goods engine. The design was completed in February 1926, and the first locomotive No. 234 Yorkshire was completed at Darlington in October 1927. The class D49 would be the last LNER 4-4-0 design to be built.

A total of 76 class D49s in three main variants were built between 1927 and 1935.

The class D49/1 variant had conventional piston valves. Twenty-eight class D49/1s were built in three batches between 1927 and 1929.

The D49/2 variant was built with rotary cam operated Lentz poppet valves. Forty-two class D49/2s were built between 1929 and 1935.

The last variant, class D49/3, had oscillating cam operated Lentz poppet valves. Only six class D49/3s were built in 1928, and these were all rebuilt as class D49/1s in 1938.

At the end of 1939, class D49/2 No. 365 The Morpeth had a set of ‘Reidinger’ infinitely variable rotary cam poppet valve gear fitted. The valves were controlled by steam pressure instead of springs. This proved troublesome and after receiving camshaft damage in January 1941, the valve gear was removed and stored. No. 365 would be rebuilt by Thompson as his prototype class D. In February 1949, British Railways re-assembled the infinitely variable rotary valve gear and fitted it to No. 62764 The Garth (ex-No. 361) with spring control refitted. No. 62764 kept this valve gear until it was withdrawn in 1958.

Thompson’s standardisation plans included a ‘class D’ locomotive for intermediate express duties. In 1942, No. 365 The Morpeth was chosen as the first rebuild to class D. The rebuild kept the same boiler, but the three-cylinder design was replaced by two inside cylinders following a pattern similar to the Robinson class D11 4-4-0 ‘Improved Director’ locomotives. Stephenson motion was used to operate piston valves. The class D rebuild was not a success, and British Railways cancelled the order for further rebuilds.

The bulk of the class D49s were allocated to the Scottish and North East (NE) areas. Usually they hauled express services, but they were also seen on some semi-fast and stopping services as well. They would often be used alongside (or replacing) NBR Reid class C11 Atlantics and Robinson class D11 ‘Directors’. The St. Margaret’s and Carlisle class D49s worked the Waverley Route, and acquired a good reputation on this difficult route.

By 1939, most of the class A3 and class V2 route restrictions had been lifted, and these locomotives had displaced the class D49s from their express passenger role. During World War Two, the Scottish class D49s were often allocated to goods workings even though they were not particularly suited to this work. After the War, the class D49s were used on stopping passenger services on the main line. The class D49 had a relatively high axle loading which restricted them from many of the branch lines.

British Railways (BR) quickly started to build large numbers of the Thompson class B1 4-6-0s which tended to displace the class D49s to less important duties. By the mid-1950s, the introduction of diesel multiple units and diesel locomotives reduced the available duties even further. Planned withdrawals in both regions started in September 1957. The last withdrawal was No. 62712 Morayshire in July 1961. Preserved by Ian Fraser, it is now owned by the National Museums of Scotland and undergoing overhaul on the Bo’ness and Kinneil Railway in Scotland.

To find out more about the class D49, visit LNER.info or wikipedia for a list of class D49 names. Volume 4 of the RCTS ‘Locomotives of the LNER’ and volume 10 of ‘Yeadon’s Register of LNER Locomotives’ covers the class in detail.