Complex sentence: Between 1937 and 1945 the system was converted to trolleybus operation, which worked on the same paths as tram system, with the exception of the Hedon Road and Corporation Pier branches which became diesel bus operated.
Split into simpler sentences: Between 1937 and 1945 the system was converted to trolleybus operation. The Hull trolleybus system worked on the same paths as tram system, with the exception of the Hedon Road and Corporation Pier branches which became diesel bus operated.