The hybrid tug is planned to be delivered in the first quarter of 2019, and will feature the same ship assist and tanker escort capabilities of existing Valor class harbor tugs, but with additional operational modes.

The new hybrid system by Rolls-Royce enables the vessel to operate direct-diesel, diesel-electric or fully-electric while assisting the large containerships and tankers operating in US West Coast ports.

This is expected to save fuel and reduce emissions. Moreover, the new system will allow loitering and transit at up to 7-8 knots in electric-only mode, then a bollard pull of 90, or nine short tons, in combined diesel-electric mode.

The tug will have two Caterpillar C3516 C Tier 3 diesel engines, each rated at 1995 kW at 1,600 rpm, supplied by Peterson Power of Portland, Ore., and two Rolls-Royce supplied 424 kW electric motors. The Z-drive system, two Rolls-Royce 255FP units, are powered from diesel engines, electric motors and from both power sources.

"The tug will have eight berths, and the major equipment on board will include a Rapp Marine electric hawser winch and a single drum tow winch. The tug is designed to carry up to 71,000 gallons of fuel and 4,300 gallons of fresh water," Jensen Maritime said.