Technology: New Nozzles Improve Northern Tug
Northern Transportation Company Ltd. of Hay River, Canada, recently completed a major refit of one of their quad screw pusher-towing tugs, the Edgar Kotokak. Vancouver's Robert Allan Ltd. provided design and engineering services for the refit which improved the operational efficiency of the tug. The refit included new CAT 3512B engines and replaced the open propellers and rudders with integrated Nautican Nozzles and Triple Rudders. Although total engine power increased from 4,500 to 5,640 hp on the Edgar Kotokak, and obviously bollard pull trials showed improvement, anecdotal evidence from the first month or so of operation seems to indicate that both the nozzles and Triple Rudders together with the new engines have improved the overall fuel efficiency.
Integrated Improvement for Tug
Young Brothers, Ltd.'s tug, the Hoku Ke'a, has returned to service after being fitted with Nautican Research and Development Ltd.'s new Integrated Nozzle and Rudder Units at Foss Shipyards in Seattle. Mark Houghton, Vice-President, Maritime Operations, of Hawaiian Tug & Barge, Young Brothers reports that on the return trip to Hawaii, "the Hoku Ke'a was able to run at reduced r.p.m. and still averaged between 9.5 and 10 knots for the Pacific transit, towing a 340 x 78 ft. barge." This is the first installation of the Nautican Integrated Units on an ocean-going tug. Prior to the conversion, the Hoku Ke'a was fitted with conventional open propellers and rudders. The 108 x 34 ft., 3,900 hp tug's bollard pull went from 88,853 lbs with open propellers to 132,810 lbs with the Nautican Nozzles.
Hydralift Skeg Use Gaining Speed
A device that increases the efficiency of barges is gaining in popularity on the West Coast, especially for Seattle to Alaska and Southeast Alaska runs. Many people report that Hydralift skegs substantially increase the efficiency of towed barges. This results in either increased towing speed or reduced fuel consumption because the horsepower required to tow at the same speed decreases. The Lynden Companies, Alaska Railbelt Marine (ARM) and Alaska Marine Lines (AML), have several barges with Hydralift skegs and another currently under construction. They are using the barges on Seattle to Alaska runs and runs within Southeast Alaska. Western Towboat Company, Inc., which does all the towing for ARM and AML, has two gravel barges with Hydralift skegs themselves.
