Morgan Foss is the latest in a long series of compact tugs designed by Robert Allan Ltd, traceable back to the late 1970s and now in widespread and increasing use throughout the world. This class of powerful and agile tug has ultimately spawned a number of imitators although few have achieved the level of elegant simplicity reflected in this vessel. The tug is essentially identical to the Mikioi, delivered in 2004, but incorporates a number of refinements from the prototype tug based on operational feedback from crews of this earlier vessel.

This example from Foss is configured strictly as a high performance day boat, with a very compact wheelhouse above a relatively simple deckhouse containing only the engine exhaust casings, vent intakes and a small day room and lavatory for the crew. Morgan Foss is just 23.77m in length overall, with a moulded beam of 10.34m and maximum draft of 4.57m. Internal tanks accommodate 10,000 US gallons of fuel oil and 500 US gallons of fresh water. The all important hull fendering comprises a heavy cylindrical rubber bow fender located above a belt of Schuyler ‘Soft-Loop’ style looped rubber sections extending around the bow and stern.

Automotive tyres are used to protect the sides of the vessel at the main sheer line level. As the aerial photograph shows, the tug has a deck spectacularly devoid of obstructions or ‘clutter’. The only deck machinery on the tug is an all-electric towing winch on the foredeck and a smaller winch aft. Markey Machinery of Seattle designed and built the model DEPCF-48 main winch, which carries 184m of 8in circumference Spectra/ Plasma towline with a breaking strain of 500,000lbs.

In order to reduce noise and vibration the main engines are resiliently mounted and a lightweight, hollow carbon-fibre shaft eliminates the need for any intermediate shaft bearings in the driveline. The result is a highly agile little vessel with a static bollard pull of 65 (short) tons. Electrical power aboard the vessel is provided by a pair of Mitsubishi 6D16-T diesel generator sets, each rated 125kW at 1,800rev/m and with a 460 volt - 3 phase, 60Hz power output.

By JACK GASTON