A team of Crowley engineers and naval architects Guido Perla designed the Response, with input from Crowley's tanker handling and escort customer, Alaska Tanker Company.

The design is based on the successful 'skeg first' Boxer class vessels of Norwegian operators Bukser Bjergnings.

Response incorporates some of the best design features of the Boxer, along with the proven capabilities of the recently built Crowley tugs.

Response is powered by two Caterpillar 3608 DITA main engines of 7,268 bhp driving twin Voith Schneider 32G II/250 cycloidal propellers. The vessel has a unique streamlined, 'high lift' hull and skeg design needed to provide the indirect towing forces and speed demands by tankers operating in Puget Sound. Response is tug of 39.47m in length with a beam of 13.92m, designed to generate a static bollard pull of 67 tons and indirect forces in excess of 152 tons at 12 knots.

Response is fitted with a Markey Model DESS-52 high performance single-drum electric towing winch designed specifically for this vessel.

The winch drum accommodates 1,000 feet of 10 inch circumference AmSteel Blue high molecular weight polyethylene line with an average strength of over 445 tons. This main towline can be shortened in at forces double the tug's static bollard pull, a condition that can occur when escorting tankers at high speed.

A full outfit of fire fighting equipment is installed and the tug can carry 2,800 gallons of foam concentrate in dedicated tanks.

During tanker escorts Crowley tugs are tethered to, or shadow, tankers to provide braking or steering assistance when needed.

Last year, Crowley tugs in Valdez, Alaska stopped a tanker that was in danger of colliding with a fishing boat that had its nets set across the shipping channel. Effectively slamming the brakes on a tanker requires a powerful, well designed tug like the Response, which, with over 7,200-horsepower, can provide enough indirect towline force to get the job done quickly and safely.