Nichols Brothers Boat Builders (NBBB) Freeland, Wash., reports that it successfully trialed and delivered Baydelta Maritime’s new 100’ x 40’ Delta class hybrid tractor tug Delta Teresa, April 16,
The vessel is the seventh tractor tug NBBB has built for Baydelta and its affiliated companies, but the first hybrid.
The tug is powered by two Caterpillar C3516 C Tier 3 diesel engines each rated at 1,995 kW @ 1,600 rpm and by two 424 kW electric motors.
The Z-drive system, two Kongsberg (formerly Rolls-Royce) 255FP units, can accept power from the diesel engines, electric motors and from both power sources.
The electric motors are powered by three CAT C9.3, 300 kW each, 480 V 3-phase @ 1,800 rpm generators, and one harbor generator a C7.1 150 kW 480 V, 3-phase @ 1,800 rpm.
The hybrid system allows for the vessel to operate in different power modes, direct-diesel, diesel-electric or fully-electric. This deliver fuel savings and reduced exhaust emissions, while suppling Baydelta with the power and vessel characteristics needed for its operations.
On trials, the tug’s performance met or exceeded all expectations. Free running speeds, under full power, of 14+ knots were obtained along with almost 10 knots on electric motor power only.
The tug has seven berths.
Major equipment on board includes; Rapp Marine electric hawser winch, and a single drum tow winch, and the drivetrain is connected with Centa carbon fiber shafts.
In addition to the drive units and hybrid system, Kongsberg supplied the control system and main switchboard, electric motors and their control cabinets.
Designed by Seattle-based Jensen Maritime Consultants, the tug carries an ABS loadline certificate and complies with USCG requirements.
Currently under contract at NBBB’s shipyard are an ATB tug for Island Tug and Barge, four 100’ tractor tugs for Foss Maritime, two high-speed catamaran ferries for Kitsap Transit alongside repair work for Golden Gate Ferries and Kelly-Ryan Services.