Crowley Complete Massive Rebuild Programme

After more than 25 years of dependable service and millions of nautical miles of ocean towing, the majority of Crowley’s ‘Invader’ class tugs have received a new lease on life via a $30 million fleet refurbishment programme.

Sentry , the final vessel in the rebuild program was completed earlier in the year at North Florida Shipyards in Jacksonville.

Crowley has 25 Invader-class tugs in all, and the series have been at the forefront of the company’s ocean towing and ship assist and escort business for decades. Conventional twin screw vessels of 41.45m in length, powered by 20 cylinder turbo-charged 7,200bhp main engines and with 67 tons bollard pull, these tugs have seen action from Prudhoe Bay, Alaska to San Juan, Puerto Rico and other locations around the world. They are known for their versatility, manoeuvrability, and ocean towing capabilities. Triple rudders are fitted for quick response and double-drum towing winches for single or tandem towing. They were originally built for Crowley between 1974 and 1977 by J.R. McDermott & Company.

Recognising the value of these tugs, in July of 1998, Tom Crowley Jr, Chairman, President and CEO of Crowley Maritime Corporation, issued a directive to return 15 of them to a like-new condition. This was expected to extend the working lives of these vessel by 15 years but after re-evaluating the work and performance of the refurbished tugs to date that is considered a conservative estimate.

As part of the programme the tugs had their engines, gearboxes, and auxiliary engines completely removed and rebuilt to the manufacturer’s original specifications. In addition, the vessels’ interiors, exteriors, and hulls received a complete facelift under the guidance of Crowley engineers and crew members.

Wheelhouse instrumentation has been upgraded and the layout of bridge equipment reinstalled using ergonomic principles.

Engine room alarms have been replaced with new and more reliable digital electronics systems. The vessels’ interiors were upgraded to include new impervious white wallboard materials to improve cleanliness and a new rubber coating was used on the interior decks and rubber tiles in the cabins to replace layers of ageing concrete.

This not only reduces noise levels but also provides extra shock absorbency for crews who are standing for much of the day.

Lighting throughout the tugs was also changed to reduce power consumption and improve light levels.

Since the refurbished tugs have been back in service, maintenance and repair costs have been dramatically reduced. This has also increased vessel utilisation and overall reliability. The tugs continue to provide towing and ship assist and escort services on the West Coast and in Alaska.

They are also key components in Crowley’s triple-deck Ro/Ro barge services between the US East Coast, the Gulf, Caribbean and Puerto Rico, and they are being used in several offshore energy projects where they are paired with Crowley’s flat-deck barges to move production components, jackets, topsides and other cargoes.