The North Eastern Railway Class S3, classified B16 by the LNER, was a class of 4-6-0 steam locomotive designed for mixed traffic work. It was designed by Vincent Raven and introduced in 1920. The earlier members of this class were fitted with Westinghouse Brakes - all of this equipment was removed during the 1930s. History After World War I, the NER experienced an increase in both freight and passenger traffic. The North Eastern Railway's express goods services were being handled by the S Class (LNER B13), S1 Class (LNER B14), and S2 Class (LNER B15) 4-6-0s, which were difficult to operate and had a high coal consumption. After superheating, all three classes proved to be much more free-steaming. However, the locomotives still struggled to keep to time with the increase in traffic. Meanwhile, express passenger traffic was being handled by the V and V/09 Classes (LNER C6) and Z Class (LNER C7) Atlantics, as well as the R Class (LNER D20) and R1 Class (LNER D21) 4-4-0s. Even though the Atlantics were doing well, the 4-4-0s were also starting to struggle with the increasing train loads. The solution came in 1919, when the NER's chief mechanical engineer, Vincent Raven came up with a 4-6-0 that could be used on both express passenger trains and express goods trains. To provide a good balance between speed and adhesion, 5-foot 8-inch driving wheels were chosen. The NER's three-cylinder layout was also used to provide plenty of power and speed. This arrangement had been used by Raven's predecessor, Wilson Worsdell and first used on his X Class (LNER T1) 4-8-0 Tanks of 1909 and his Y Class (LNER A7) Pacific Tanks of 1910. All three cylinders used Stephenson link motion. On the Y Class, the cylinders drove the front driving axle; on the X Class, meanwhile, they drove the second axle. In both cases, this provided a powerful locomotive that was also easy to maintain and repair. The boiler would also be interchangeable with the T3 Class (LNER Q7) 0-8-0s, much like the S2s, which had interchangeable wheels and cylinders with the S Class and interchangeable cylinders and boilers with the T2 Class (LNER Q6) 0-8-0s. The result was the S3 Class (LNER B16), with the first five members, Nos. 840-844 appearing in December 1919 from Darlington Works. Post-NER Seventy S3/B16 locomotives were built between 1919 and 1924. The NER began numbering this class