Complex sentence: These were replaced by more powerful units in the early 1920s, which were withdrawn from passenger service in 1962 after electrification reached Amersham and A Stock electric multiple units entered service.
Split into simpler sentences: These were replaced by more powerful units in the early 1920s. The locomotives were withdrawn from passenger service in 1962 after electrification reached Amersham and the A Stock electric multiple units entered service.