Complex sentence: Unloading explosive ordnance directly onto the dock was against port regulations since ships with such cargoes were supposed to be moored in the center of the harbor and their high-risk cargo unloaded onto lighters.
Split into simpler sentences: Unloading explosive ordnance directly onto the dock was against port regulations. Ships with such cargoes were supposed to be moored in the center of the harbor and their high-risk cargo unloaded onto lighters.