Crowley looks forward to its first ‘Ocean’ class tug

To be named Ocean Wave, this vessel, due for completion before the end of the year, represents the first of a new generation of seagoing tugs equipped for long range towing, salvage and offshore support operations.

At a recent ceremony, Chris Bollinger, executive vice president of new construction at Bollinger Shipyards, presented a model of the new ‘Ocean’ class tug to Crowley’s, president, chairman and CEO, Tom Crowley. He said; “We are pleased to unveil this model of the new Ocean class design for Crowley, as they expand their fleet with additional high quality tugs to meet the needs of their clients. We look forward to the delivery and christening of the Ocean Wave and sister ships Ocean Wind, Ocean Sun and Ocean Sky”.

Tom Crowley replied, "We are continuing to make the investments necessary to address the needs of our customers, who are looking for best-in-class, modern and environmentally friendly equipment. Crowley has always been an industry leader in tug design, technology and performance, and these new vessels are a reflection of our continued commitment to that.”

Just a few weeks later the hull and all major steelwork for Ocean Wave was completed and fitting out well underway. This first tug is due for delivery during the last quarter of this year and the remainder scheduled for completion in 2012.

The Ocean class tugs are being built to a unique new design resulting from the combined efforts of Bollinger’s engineering department, Crowley’s subsidiary Jensen Maritime Consultants, and technical staff from Crowley Vessel Management Services.

Ocean Wave and its sister ships will be 44.4m in length, with a breadth of 14m and depth of 7.92m. The hull is double skinned with transverse frames and transverse and longitudinal bulkheads, including a collision bulkhead extending to the main deck, all of which is designed to prevent any accidental overboard discharges of fuel or other potentially polluting fluids.

The vessels will be classed American Bureau of Shipping (ABS) +A-1, Towing and AMS, Fi-Fi 1 firefighting, USCG, SOLAS, International Load Line Certificate and will be operated under the US flag. During construction, each vessel will be documented and receive Green Passport certification.

A twin screw propulsion system will be installed, powered by two Tier II compliant Caterpillar C-280-12 main engines generating a total of 10,880 bhp. The engines are capable of being upgraded at a later date to meet the requirements of Tier III or Tier IV. Power will be transmitted via Reintjes LAF 5666 reduction gearboxes to 3.9m diameter, four blade, controllable pitch propellers turning in fixed nozzles. High lift rudders will be fitted and, to enhance maneuverability further, one Berg VFD-850 electrically powered bow thruster will be installed.

The first two tugs Ocean Wave and Ocean Wind will be equipped for single lever control to DP-1 standards and the second pair Ocean Sun and Ocean Sky will have enhanced DP-2 systems.

Electrical power for the onboard systems will be supplied by two 1475 kVA shaft generators, one 340kW Caterpillar C-18 auxiliary generator and one 125kW Caterpillar C-6.6 125 harbour/emergency generator. Both diesel generators are Tier II compliant and upgradable to Tier III or IV.

A minimum bollard pull of 150 tons is anticipated along with a range of approximately 12,600 nautical miles at a free running speed 15 knots. The vessels will be equipped for long range, high performance ocean towing and incorporate features designed with personnel safety as a priority. Work on deck will be made easier and safer by installing a waterfall style winch, shark jaws and retractable pins, all controlled from the wheelhouse, keeping the deck clear of personnel and creating a safer working environment.

The accommodation has been designed using ergonomic principles and comfort levels will minimize fatigue and reduce injuries to the crew while at sea.

Once in service, vessels of the Ocean class will be capable of rig moves, platform and FPSO tows, emergency response, rescue towing, fire-fighting, and have the capability to support salvage under the US Navy's SUPSALV Contract.

Bollinger Shipyards, Inc. is a leading designer and builder of ocean going tugs, double hull barges, offshore oil field support vessels, rigs, lift-boats, inland waterways push boats and barges, fast military patrol boats and other steel and aluminium products from its three new shipyards. The organisation has 12 shipyards, all strategically located between New Orleans and Houston with direct access to the Gulf of Mexico. Interestingly, it was in the same shipyard, while in the hands of McDermott Marine, that 23 out of the 24 iconic Crowley ‘Invader’ class tugs were constructed during the 1970s. A large number are still in service following an extensive mid-life refurbishment.