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PROPULSION

GROUP THINK

Renk opened one of Europe’s most modern test facilities for gear units in Augsburg

Collaboration early on between stakeholders can mean a more efficient, LOWER COST vessel

V

essel operators are still very much focused on reducing fuel consumption and lowering emissions. Collaboration early on in the design of a new vessel and its construction between the vessel owner, naval architects, shipbuilders, and propulsion manufacturers can payoff in optimizing the vessel’s hull, reducing costs of construction, and lowering operational costs during a vessel’s lifetime. “We work with naval architects early in the design process to help optimize the propulsion system, looking to meet all design requirements while minimizing the size and horsepower of the system,” says Elizabeth Boyd, PE, President, Nautican Research & Development Ltd. Boyd says collaboration early in the design phase “can result in significant savings because if the horsepower can be reduced due to efficiency gains, it can lead to size reductions in not just the horsepower and propellers, but also everything that goes along with it—shafts, bearings, etc.—sometimes it can even mean meeting the requirements with a smaller boat. We can quickly show performance and full system configuration for different sizes, allowing the naval architect to explore options very quickly.” Nautican’s foundation was built on efficiency. More than 40 years ago, company founder Josip Gruzling pioneered the use of hydrofoils to increase the efficiency of tugs and barges. Today, Nautican engineers and manufactures hydrodynamic solutions, including patented Integrated Propulsion Units, High efficiency nozzles and propellers, high aspect ratio triple rudders, pre-swirl stators, and also hydralift skegs for barges. It says independent tests show that its propulsion system solutions increase power and maneuverability, while significantly reducing fuel use and maintenance needs.

Compiled by Marine Log Staff

One of Nautican’s latest projects is fabricating the first two sets of 104-inch nozzle units for the 120 ft Kirby Offshore Marine line haul tugs under construction at Nichols Brothers Boat Builders, Whidbey Island, WA. According to Boyd, initially nozzle development was done using both Computational Fluid Dynamics (CFD) and physical testing in a cavitation tunnel and towing tank. “However,” she says, “our CFD efforts now are focused more on integration with the hull form. For these boats, CFD was not used as the design was already well developed and fairly straight-forward as far as placing the nozzles.” The designer of the ABS Class tugs is Jensen Maritime, Crowley Maritime Corp.’s Seattle-based naval architecture and marine engineering company. Each of the two tugboats will be equipped with two Caterpillar 3516C main engines, rated at 2,447 hp at 1,600 rev/min. Reintjes reduction gears, supplied by Karl Senner, LLC, Kenner, LA, will turn two Nautican fixed-pitch propellers with fixed nozzles. Other equipment onboard the tugs will include two C7.1 Caterpillar generators for electrical service, one TESD-34 Markey tow winch, one CEW-60 Markey electric capstan and one Smith Berger Town Pin. “Kirby owns many boats with Nautican systems, but most of these have been ATBs (Articulated Tug Barge units) to date,” says Boyd. “We worked recently with Nichols on a pair of Kirby 10,000 hp ATB tugs—this project went very well and these vessels are performing exceptionally well in service.”     Nautican designed larger 120 inch nozzle units for another tug for Dunlap Towing. “Dunlap is a Nautican repeat customer,” says Boyd. August 2016 MARINE LOG 47

August 2016 Marine Log  
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