When did the idea of diesel powered ships begin?

Question

any ideas thanks

Answer 1

Marine engines went from steam to petrol.  Spirits derived from petrol made fast gasoline torpedo boats but oil fired engines were deemed safer for larger vessels.   It wasn't until during development of Naval submersibles did R&D aquire the deep pockets to develop a line of diesel boats.  There had been previous diesel engines but the post-war surplus

actually jump-started the wider applications to present day.