LB&SCR J2 Class

The LB&SCR J2 Class was a series of outside-cylinder 4-6-2 Baltic side-tank express locomotives designed by Lawson Billinton and introduced at Brighton Works in 1912, a development of Marsh's J1 Baltic tank that applied Billinton's own design refinements to the established 4-6-2T configuration. Where the J1 had been Marsh's pioneering adoption of the Baltic tank wheel arrangement for LBSCR express working, the J2 represented Billinton's considered development of the concept, incorporating lessons from the J1's service experience into a revised boiler and detail specification.

Billinton's J2 improvements addressed operating characteristics observed with the J1 in LBSCR service, particularly regarding steam production on the harder schedules of the Victoria–Brighton express. The revised boiler proportions and Billinton's own detail preferences gave the J2 marginally better performance on the heaviest express duties, making it the definitive LBSCR Baltic tank type.

The J2s worked the LBSCR's heaviest express services through the final years of the company's independence and passed to the Southern Railway in 1923, where they continued on former-LBSCR express routes. None was preserved.