When I was in China I saw hundreds of boats using the horizontal singles. A boat of around 30' used one engine. The 100'+ barges used from 3 to 5 20 hp engines on a line shaft. They started as many engines as needed to haul the load. These barges were loaded with dirt from dredging, iron ore, or scrap steel, ect and were loaded to the point that the barge was only 4-5" out of the water! A single bow wave from another boat would have sunk them! The water rules in Suzhou were that in the city canals only one engine could be run. On the open canals all 5 were belted up and were moving hundreds of tons of material.
I've been through the Changfa factory and they have a very good operation. There are, however, many other very good brands of the same style engine available. The Laidong factory also builds nice engines but is more oriented to 3, 4, and 6 cylinder diesels for heavy equipment, trucks, buses, and automobiles. They do build a very nice horizontal engine too. I've got a stack of brochures and manuals from the various factories over a foot thick from all of the factories I visited. I went to China with another importer and by a gentleman's agreement we decided that we wouldn't step on each others toes. He sells Changfa type engines and I sell Lister type engines.
Mike Montieth
Listeroids/USA