New tug design for Moran from Washburn & Doughty

Due for a late 2011 launching at Washburn & Doughty Associates is a newly designed 93’×38’×15’6″ tug for Moran Towing Corp., New Canaan, Conn. This will be the first tug built to the East Boothbay, Maine, boatyard’s latest design.

The tug will be a step up in a lot of ways over Washburn & Doughty’s 92’×32′ model, from which 22 tugs are currently in operation.

The 92-footer was limited to 5,000 hp, but the new design, which is a foot longer, 6′ wider and 18″ deeper, can carry much larger and heavier Z-drives and thus produce more power. Moran’s newest tug will have two MTU M63L engines, each putting out 3,000 hp through Schottel SRP 1515 FP drives. The package will deliver 70 metric tons of bollard pull ahead and 66 astern.

“We were looking for something that could carry more power,” said the yard’s Bruce Washburn. In addition, some potential customers wanted to put a heavier towing winch on the tug’s stern, and the 92-footer couldn’t carry that weight.

Throw in an interest in having a tug in this size range that’s able to do escort work, which also requires more freeboard and a deeper keel.

The added beam also allows some crew quarters to be moved below deck. “We’ve given the crew extra room and put a head down below,” Washburn said.

If you visit the engine room, you might observe what looks like extra or unused space. While currently there are no fire pumps or monitors planned for the tug, they might be installed in the future.

So on the computer design program, the engine room was first laid out as if the pumps and piping were there. “In laying everything else out, we worked around that. If there are fire pumps in this one or a follow-up boat, we don’t have to rearrange the engine room,” Washburn explained.

Up on deck, there will be a Markey DEPC-48 electric hawser winch forward and a Markey CEWC-60 electric hawser capstan aft.

The 93-footer also features an “open-skeg” design that is a first for Washburn & Doughty. “We had the calculations run on escorting and it seems to give a little better performance,” Washburn said.

Reducing skeg area aft means that when doing escort work there is less drag and the stern can be pushed up easier into the current, according to Washburn. The open framing also provides docking structure. “In essence it gives a post for docking, and the boxed structure between the post and the keel, with top and bottom plates 1½”×12″ and 12″×1″ side plates, will support the tug.”   

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