The 185 ft freezer-trawler F/V Araho is being built at Eastern Shipbuilding
All-electric winches for new fishing trawler
app Hydema, Seattle, WA, has landed a contract to outfit the new trawler F/V Araho. The 185 ft freezer-trawler is being built at Eastern Shipbuilding, in Pensacola, FL, for O’Hara Corporation, with delivery scheduled for mid 2015. The owners had originally planned to retrofit the F/V Harvester Enterprise, but instead opted for an outright newbuild. Changes heralded by the American Fisheries Act encouraged such an approach. Long anticipated, the new trawler build could thus mark the first of several new trawler builds, to replace aging hulls throughout the Alaskan trawl fleet. “Rapp worked hard, and through several evolutions, to win the contract,” noted O’Hara Corporation’s Sewall Maddock s. “We have had a long-standing relationship with Rapp, and we have Rapp winches on all three of our trawlers in Alaskan waters. We were impressed with Rapp’s electric winches on the Icelandic trawler Thorunn Sveinsdottir, as well as the NOAA and other research vessels Rapp has outfitted,” Sewall added. The Rapp package includes a pair of TWS-22051RE electric trawl winches. Each achieves 45 metric tons line pull, at 45 meters per-minute line speed, at bare drum and speed step 1 (the winches feature two-speed capability). Each accommodates 2,830 meters of 32mm wire rope. Powering both these workhorse winches are Rapp’s own gearboxes, which have proven very durable since the first was introduced some 20 plus years ago. And three of Rapp’s patented liquid-cooled motors are mounted on each gearbox; such as the Rapp gearbox, this product has won very wide acclaim, including an innovative technology award (at the Offshore Technology Conference), in recent years.
58 MARINE LOG September 2013
The Rapp package also includes two electric GW-4000BE Gilson winches, which attain 32.2 metric tons line pull, at 30 meters per minute line speed. Three electric Rapp net drums were also included, with line pulls and speeds corresponding to the Gilson capability. Three GW-2300BE Codend/Outhaul winches were also ordered—these lifting 12 metric tons at 32 meters per minute line speed. Rounding out the deck machinery is a single SOW-502E/S6 Net-Sounding Winch, with a line pull of 3.5 metric tons at 80 meters per minute; Rapp is also providing two anchor winches and a hydraulic capstan. Rapp’s render-recover winch management system, the PTS (Programmable Trawl System) Pentagon Fisheries system, will provide local and remote winch control, including a variety of automated functions and read-outs on the bridge. The Rapp winches’ Drive System is based upon VFDs (variable-frequency drives) and a DC link system. The preference for electric over hydraulic is based on many factors, and spans offshore platforms and vessels in a variety of marine applications. Overall efficiency of the electric-driven winches is greater, owing in part to the fact that hydraulic systems have many steps in the power train and pressure losses in control valves and piping. In electric systems, the total grade of efficiency is 80-85%, versus 65-70% for hydraulic. This means that power requirements for electric systems are lower. Further, electric winches allow for regeneration of power during payout and trawling, providing additional energy savings compared to hydraulic systems. The next decade, therefore, should mark interesting developments, as the world’s largest factory-trawler fleet looks to update or replace a number of aged hulls. ■