Complex sentence: Initially, the engine cars were designed and installed to have same pusher configuration as the "Hindenburg", but after the disaster, the engine pods were completely redesigned and reinstalled, using diesel engines powering tractor propellers.
Split into simpler sentences: Initially, the engine cars were designed and installed to have same pusher configuration as the "Hindenburg". After the Hindenburg disater, however, the engine pods were completely redesigned and reinstalled, using diesel engines powering tractor propellers.