Marine Engine Diamond Diesels (UK) Ltd a well-established business is the place to be. Located at Unit A, Martree Business Park, Rudgate, Thorp Arch, Leeds, LS23 7AU. We are the UK importer and distributor of Mitsubishi Marine Engines, Industrial Engines and Genuine Mitsubishi Spare Parts. They can provide you with Industrial Diesel Engines for Generators and variable speed applications. Marine Diesel Engines for Propulsion.