Complex sentence: The main turbine failed after eleven years in heavy service through a war, and it was converted to piston drive in 1949 and withdrawn after the deadly Harrow and Wealdstone railway accident in 1952.
Split into simpler sentences: The main turbine failed after eleven years in heavy service. The Turbomotive was converted to piston drive in 1949 and withdrawn after the deadly Harrow and Wealdstone railway accident in 1952.