Lister Blackstone marine engines came about as the result of a merger of British engine companies in 1936. The R. A. Lister Company bought out Blackstone and Company in order to gain access to the large engine market. All the marine engines were reserved almost exclusively for commercial or military boats, though some were used in private yachts. Lister Blackstone marine engines are now considered an antiquity, though Lister continues to make marine engines under its own name.
All the Lister Blackstone marine engines are diesels. Most are air-cooled diesels. Diesel engines are preferred in most large, commercial applications because of their superior longevity and ability to generate greater horsepower and torque at lower temperatures and rpms.
Size and Shape
Lister Blackstone produced marine engines from those that that generated as little as 8.5hp all the way up to giants that would produce 1,520hp. Many larger ships had multiple engines. Most of the Lister Blackstone line were traditional vertical engines, but in 1939 the company designed what it called the "M" class of engines. It was a low, horizontal engine that ranged from a four-cylinder, 200-hp model to a 16-cylinder 1,520-hp. engine. None of them stood taller than eight feet high, which the company used as a sales feature because they could easily fit between decks. It had a wider application in industrial settings, though, because service engineers found the engines too restricted on ships to work on easily.
Bore and Stroke
Though the companies originally combined to gain greater access to the large engine market, the company quickly decided to improve upon existing small diesel marine engines. The first major innovation, the "P" engine had a bore and stroke of 7 1/4 by 9 1/2 inches, which produced 26hp at 700rpm. Within a year, the company introduced the "JP" line, with a bore and stroke of only 5 by 7 1/2 inches. It produced 16hp at 800rpm.
During World War II, Lister Blackstone marine engines went in British minesweepers. The engines were also extensively used throughout the military branches for non-marine applications. They powered military installations, helped with the generation of electricity and extensively powered agricultural implements.