Mississippi River and Gulf intracoastal barge operators Southern Towing Company informs they are having four push-boats (designed by Ed Shearer & Associates) built at Alabama’s Steiner Shipyard in Bayou La Batre; vessels that will have an unusual propulsion system installed when the first of them is delivered by year’s end. Southern Towing Push-Boat: Photo courtesy of Southern Towing The first two 100-ft push-boats will be equipped with hydraulically operated Z-drive propulsion units powered by two MTU 8V 4000 M23S engines running at a constant speed. In this design, unusual on the U.S. inland waterways, the propulsion engines run at a constant 1,800 rpm, while the hydraulic propulsion unit provides fully proportional speed control to a fixed-pitch propeller in a 360-degree azimuth Z-drive. An advantage is that the 1,234 bhp engines will also be powering generators to supply hotel loads on the boats, eliminating the cost of separate generator sets.The other two, la... [More]