During the late seventies, Oosterhuis Industries researched the U.S. domestic and foreign engine market for lower horsepower, high-rpm diesels capable of operating successfully on lower-quality fuel oils. This search resulted in the appointment of Oosterhuis as distributors of SN and Daiya diesels for Mitsubishi Heavy Industries America, Inc.
The high-speed Mitsubishi SN Series diesel engines are manufactured by Mitsubishi at its modern plant in Sagamihara near Tokyo, and shipped to Oosterhuis in standard execution. At Oosterhuis' facilities, engines are further packaged for U.S. domestic use, which includes the installation of U.S.-made SN full-flow lube oil filters, and the incorporation of Synchro-Start overspeed devices and Murphy instrument panels.
The Mitsubishi SN Series are available in a power range of 350 to 1,600-bhp as propulsion units for offshore supply vessels, tugboats, pushboats, and for generator drives and other applications. The rpm ranges from 1,200 to 1,800 at maximum continuous rating.
Recent orders include quadruple engine installations for tug/supply vessels utilizing two S16N and two S8N engines driving through hydraulic compound gears, with master and slave controls and fixed propeller. The 8-cylinder S8N starboard engine drives, while disconnected from the propeller shaft, a mud compressor by means of a front-mounted power take-off. The portside S8N engine has a similar hook-up with a fire pump connected to a high-pressure, large-capacity fire monitor on deck. Other quadruple installations call for use of four S16N engines with controllable-pitch propellers.
In addition to the packaging and marketing of Mitsubishi SN diesels, Oosterhuis Industries, through its affiliated company, American Brons Corporation, maintains a license for manufacturing of Turbodiesels designed by Brons Industrie of the Netherlands. The first American Brons diesels became operational during 1979. They have logged approximately 10,000 hours, and have proven to be reliable and economical to operate.