The M7 Class of 0-4-4Ts was designed by Dugald Drummond for the London and South Western Railway (LSWR) and 105 of them were built between 1897 and 1911. Fifty of the Class were built with longer frames noticeable by the greater overhang of the front buffer beam area and were originally known as the X14 Class. Most of these were subsequently equipped for push-pull working and were a common sight on branch lines in the South and South West of England. Many of the class were based at Nine Elms depot and took turns operating formidable loads of empty passenger trains to and from Waterloo. Most of the Class survived until the early 1960s, with the last few based at Bournemouth until withdrawal in May 1964.