On January 4, US shipyard Washburn and Doughty Associates began construction of a 28.3-metre, 4,475kW Z-Drive tug for Moran Towing of Connecticut.
This new in-house design is based upon their 28- by 9.8-metre design, of which there are 22 tugs in operation. Washburn and Doughty hopes the increased length and beam will allow for increased power, while maintaining the manoeuvring characteristics and handling capabilities of the original.
The vessel will be classed ABS Maltese Cross A1, Maltese Cross AMS, Towing Vessel, Escort Vessel, and be powered by two MTU M63L16 cylinder series 4000 main engines each rated at 2,250kW at 1,800RPM. The propulsion units will be Schottel model SRP 1515 FP drives, equipped with stainless steel propellers measuring 2,600mm in diameter and nozzles lined with stainless steel. Bollard pull is anticipated to be 70 tonnes ahead and 66 tonnes astern.
The tug will feature a machinery alarm system assembled by First Electric Motor Services and built from Siemens components.
The vessel will be outfitted with two John Deere model 6068TFM76, Tier 2 emissions certified 1,800RPM marine engines providing 99kW, 120/208 VAC, three-phase power. Under normal conditions, one generator will be on-line for ship's service and the other will be on standby. In the event that the on-line generator fails, the standby generator will automatically go on-line and the generator experiencing the failure will automatically shut down.
The main switchboard will be located in the engine room. It will be of the non-paralleling split bus type and be fitted for automatic transfer from the on-line generator to the standby generator. The switchboard contains PLCs to control generator shutdown, transfer and starting. Override switches will be provided to operate the circuit breaker in event of loss of 24 VDC power.
The vessel will be equipped with a Markey DEPC-48 electric hawser winch forward and a Markey CEWC-60 electric hawser capstan aft.
Bow fendering will be two courses of cylindrical fender up high along with soft loop and wing type sub fender below. A course of D-fendering will be fitted at the main deck extending from the bow fenders at the sides and around the stern.