The Bering Sea Pollock fishery is the largest volume fishery in the world. Pollock are similar to cod though much smaller at about 10% of the size of the larger Pacific Cod. Both fish are abundant in the Bering Sea.
The Pollock are almost entirely harvested by trawl nets. The Outer Trawl nets used in this fishing can be as large as 1000 feet across the opening. The otter trawl net features wing foils that are towed by warp lines and it is these foils that hold the net open.
The task of towing these large nets is done by vessels ranging from 60 feet to 300 fee with most being 100 ft to 200 ft in length. Some boats can deliver 1,000,000 pounds at a time. Most of the boats are equipped with “Kort Nozzles’ which duct the propeller. These nozzles always hamper the maneuverability therefore encumbered by the largest net possible it becomes difficult to maneuver with currents, other vessels, and the desire to tow back through a productive area.
At DMR we have refit a number of vessels in this large powerful fleet with our rudders. The response has been enthusiastic. The operators of one large vessel report that they were able to pay for the cost of the installation within the first year. The ability to turn 180° and tow back through an area was reduced from 5 miles to .8 tenths of a mile. The captain reports that he could now tow on autopilot entirely and hold tracks along bottom contours that he would have been swept off of before. One other comment of Capt. Brian is that regardless of the weather while in transit the boat tracks so straightly that the RAI can barely be seen to move.
Speaking to the officers of the Bering Defender another similar sized trawler, the response was similar. In fact they stated that the DMR rudders were essential to their productivity. We are presently quoting and scheduling work to replace the rudders on other boats in the fleets of both B & N Fisheries and Global Seas.
Bering Defender Please Click any image to enlarge