The A2 locomotives were built between 1907 and 1922. There introduction to service coincides with the introduction of new passenger rolling stock introduced to replace bogie country stock being converted for suburban service.
Numbers 816 to 939 were fitted with Stephenson valve gear.
Numbers 940 to 999 were fitted with Walschaert valve gear. This group was converted to oil burners 1945/1946.
By the 1950's they were being scrapped at the rate of 15 to 20 per year.