Z-drives find favour on US waterways

摘要

A step change is taking place in the US inland shipping fleet, whereby a number of towboat operators are nominating azimuth stern drive (ASD) propulsion, or Z-drives. Towboats on the US inland system and the Gulf Intracoastal Waterway have traditionally employed main engines and reduction gearboxes connected to long drive shafts and a propeller held in place by a substantial support structure, with rudders forward and aft of the propeller.