"It is exciting to see our vessels coming and going through the harbor, I particularly enjoy that fact that we appear to be one of the busiest, and best looking fleets on the water," says Island Tug and Barge Ltd. President Bob Shields
of the view from his harbour side office in Vancouver, BC. Capt. Shields has built a reputation as a boat proud innovator in the already innovative British Columbia towboating industry. This reputation was furthered last year when Shields and his partner, Capt. Jack Davies
, retrofitted an Intercon connector to their handsome 41.5 by 9.75-metre 3000 HP twin-screw tug Island Monarch. Now, a year later, Vancouver waterfront watchers are seeing the company repower their classic raised-focsle style Island Crown with a pair of Cummins (CMI)
KTA38. This is an engine package that is winning followers around the world from China and India to Louisiana and the United Kingdom. Recently, in British Columbia, a pair of new tugs with Cummins KTA38 engines attracted attention that was redoubled when that owner followed up with a KTA38 repower. Now with Island Tug and Barge choosing the same power package it has become a leader on the coast. The 23.7x7.32-metre Island Crown is one of those distinctively Canadian tugs whose raised focsle design resulted from a requirement that all crews' quarters must be above the waterline. Built in 1974 to a Robert Allan design, she was first Christened the Gulf Julia. Later, renamed the Seaspan Defender she has more than earned her keep over the past three decades towing along the Pacific coast. But this was a well designed and well built boat and her owners felt secure in doing a routine repower to extend her life. An old pair of 725 HP engines pulled out and replaced with the new Cummins KTA38M0 engines. The new engines have been de-rated to 500 HP each at 1600 RPM but are designed capable of 800 HP each at 1800 RPM. The existing Twin Disc TD540 7:1 marine gears were sent out for rebuilding and reinstalled. The three-blade propellers in nozzles were kept to their original 74X78-inch dimensions. Shields explains, "We had Robert Allan Ltd. do a complete engineering study for us on the re-powering and were amazed to discover that the propellers were an absolute perfect match for the two ratings of the Cummins engines."
The real measure of a tug is pulling power and experienced owners know that translates to earnings. "We didn't do a bollard pull test, but believe we are getting slightly better performance than prior to the re-power. We estimate the bollard pull at 36,500 lbs at the 500 hp rating and 57,750 lbs at the 800 hp rating," explains Shields.
While the engine selection and preparation was a detailed and intense process, the actual lowering of the two 9,000 pound engines was accomplished in a solid morning of work. A well coordinated team that worked with a rented crane to lower the machinery through a hatch in the top of the fiddley. The engines, lifted with a specially designed jig, were stood on their head to fit through the hatch with bare inches to spare. The gears followed and were mated to the engines and shafts.
Port Engineer Andy Farmer is pleased with the installation and is looking forward to the operation of the engines with their Eliminator and Centinel options that effectively eliminate the need for oil changes. The two systems combine to reduce operating and maintenance costs while creating an environmentally friendly operating regime. The Cummins-designed Eliminator removes all disposable lube oil filters. The Centinel Oil Management, an oil burn system, works in conjunction with the Eliminator to virtually negate the need for oil changes and costly waste oil disposal. A lot has changed in engine and vessel design since the Island Crown (ex Gulf Julia, ex Seaspan Defender) was launched in 1974, but the confidence that her owners have shown with her repower will assure her many more years of service.