The Island Defender tugboat has had its share of jobs and homes since it was built in 1977. The tug was originally built as the Hamilton Bailey and was used for log towing n Vancouver, British Columbia, Canada. Later, the boat was shipped to the Great Lakes and renamed the Josee M. Eventually, the well-traveled tug made its way back to the Pacific Coast and sold to Vancouver’s Island Tug and Barge, where it was renamed Island Defender.
Originally, the tug was outfitted with a pair of 358 kW Caterpillar D346 main engines. When it was relocated to the Great Lakes, it was repowered with a pair of Detroit DDEC V16-92 engines rated 820 kW each at 2100 r/min. Now back in Vancouver and working for Island Tug and Barge towing 25 000 barrel fuel barges and 5500 tonne deck barges, the vessel received an overhaul complete with its third set of engines.
For its third set of engines, the 21 by 7.28 m Island Defender received a pair of Cummins KT19s rated 373 kW each. The reduced output from the previous Detroit engines will actually increase the tug’s profitability as Canadian crewing regulations require a full-time engineer in tugs with more than 746 kW, and the smaller engines use less fuel.
The engines are soft mounted and connected to the drivetrain via a Centa Link coupling, a design expected to reduce vessel noise. Cummins also supplied the engine montoring and control panels in the main wheel house. Also added were a Krill fuel management and monitoring system, new shafts and Kobelt shaft brakes, Rice nozzles and propellers and a pair of John Deere gen-sets. Island Tug opted to keep the existing ZF 5.037:1 gears and sent them out to be refurbished and adapted from the direct link they had to the old engines to a flexible link to the new Cummins engines.
The new Rice nozzles and threeblade propellers were installed with the trailing edge of the nozzles cut away to all the placement of the rudders within 15 to 18 cm of the wheels for improved handling. Even with the reduction in power output from the main engines, the new configuration is expected to produce improved performance.
Island Tug said that according to RAL predictive graphs, the new nozzles will produce a static bollard pull of 15 422 kg, and with a 5500 tonne barge, the vessel should run at 7 knots loaded and 9 knots empty an efficiency increase of 8%. In addition to the new powertrain, the tug received additional upgrades and fixes. The sponsons were opened up, blasted, painted inside and divided into four compartments before being resealed. The entire bulwark steel around the aft deck and stern was replaced, the towing pins were updated with new parts and the Burrard single drum winch was rebuilt.
Some of the bunk rooms and the galley were also refurbished, and the deck was refinished with a sound dampening system that includes layers of a cork-concrete mix and perforated aluminum topped with an acrylic flake finish. The entire project took about a year to complete.
Source: Diesel & Gas Turbine Worldwide