[1] It was the LNER's equivalent to the highly successful GWR Hall Class and the LMS Stanier Black Five, two-cylinder mixed traffic 4-6-0s.

However, it had the additional requirement of having to be cheap because, due to wartime and post-war economies, the LNER, never the richest railway company, had to make savings.

It was the first 2-cylinder main-line locomotive constructed for the LNER since the grouping, such had been Sir Nigel Gresley's faith in the 3 cylinder layout.

With cost saving a wartime priority the LNER's draughtsmen went to great lengths to re-use existing patterns, jigs and tools to economise on materials and labour.

1000) coincided with a visit to Britain by the Prime Minister of South Africa, Field Marshal Jan Smuts, and, as mentioned above, it was named Springbok.

However, Thompson then placed substantial orders with two outside builders: Vulcan Foundry and the North British Locomotive Company of Glasgow.

The first batch was distributed among depots on the former Great Eastern Railway section: Ipswich, Norwich, and Stratford in London.

Engines based at Darnall, Sheffield were regularly rostered for the Master Cutler and South Yorkshireman expresses.

The last scheduled steam-hauled passenger train to arrive in Liverpool Street was the up Day Continental on 9 September 1962 hauled by a B1 61156.

This led to the fact that the Class B1 contained the shortest name given to a British locomotive ((6)1018 Gnu) and one of the longest ((6)1221 Sir Alexander Erskine-Hill).

(* denotes historically inauthentic) In 2007, Bachmann introduced a OO gauge model of the B1 in BR black livery.