Washington-based boatyard Modutech Marine has commenced its rollout of 24 support tugs to the US Navy, the debut vessel having been delivered in December 2017. Built under the class handle of ‘Work Boat Medium’ and designed by fellow Washingtonian naval architect Hockema & Whalen and Associates, each tug in this series measures 9.14m x 4.57m and has been produced to draw 1.65m. The US Navy expects to take delivery of all 24 tugs by December 2019.
Each tug can rely on a bollard pull of nearly 8tonnes, courtesy of a pair of Cummins QSL 9 diesel engines. Rated 425kW combined, these engines drive two propellers via ZF W325 gears with 3:1 reduction – an arrangement that grants the tugs a service speed of 9knots, when they are not busy providing support to US Navy warships. Cummins adds: “Triple shutter-type rudders are mounted behind each prop.”
Design features include wide side decks, for enhanced personnel safety whilst working on deck. The deck is equipped with an 181kg davit, which can be moved to port or starboard mounts, and a pair of deck winches, located forward, starboard and port.