Garth & Lindsey Foss Enhanced Tractor Tug Design

Client:

Foss Maritime Company
Completion Date:

1994
Key Collaborators:

ARCO

Halter Equitable
Project Type:

Vessel Design & Modification, Tugs & Workboats
Service Categories:

Naval Architecture

Marine Engineering

Owner Services & Onsite Support
Vessel Overview:

Two 150-foot, 8,000-horsepower enhanced tractor tugs
Challenge:

Design first-of-its-kind firefighting tanker escort tugs.

THE FIRST PURPOSE-DESIGNED ESCORT TANKER TUGS.

After the Exxon Valdez oil spill and the passing of the Oil Pollution Act of 1990, Foss Maritime and ARCO joined forces to provide mandatory tanker escort services to the oil refineries in North Puget Sound. Foss envisioned a first class, highly capable Voith tractor tug that could operate stern-first at 12 knots while tethered to a tanker, generating a towline pull force that would far exceed its bollard pull when in indirect mode at speed. Foss came to Glosten with their concept and styling—aesthetics were very important—and hired us to lead the design and engineering of a new vessel type: the escort tug.

SETTING THE STANDARD.

Glosten’s engineers packed 8,000 horsepower, firefighting pumps, and giant Voith propellers into the hull of what would become the two largest and most powerful tanker escort tugs in North America. Their size and power would allow for the close escort of tankers at higher speeds, while providing quick response and high maneuvering forces for emergencies. Our ocean engineers demonstrated the effectiveness of the design by modeling steering and braking performance to simulate tanker steering or propulsion failure in the sensitive areas of Rosario Strait, and Noise Control Engineering provided state-of-the-art noise control features. After completing the preliminary and contract design, Glosten was retained as onsite construction representative during construction at Halter Equitable in Louisiana.

The Garth and Lindsey Foss entered service in 1994 and have operated successfully ever since, escorting tankers from Port Angeles to the Northwest refineries. They set the standard for escort tug design and continue to be some of the best-looking, most distinctive tugs on the water.