Bering Sea trawler Araho installs 14 electric winches — but will it set a trend?
While hydraulic winches have earned their spot on commercial vessels, a trend among new construction boats is to outfit the deck gear with electric models for reliability and efficiency.
Take for example the trawler Araho, launched last year at Eastern Shipbuilding Group in Panama City, Fla., and put into service early this year in the Bering Sea for the Maine-based O’Hara Corp. (see “Araho arrives,” NF, May ’17, p. 28). A total of 14 winches were installed around the 194-footer, and all of them but the anchor winch have electric drives. The boat was designed by Norway’s Skipsteknisk, and Rapp Marine, also Norwegian, supplied the winches and technology to tie the systems together.
“Probably, in general, we are selling 70 to 75 percent electric winches. The trend is definitely there,” explains Johann Sigurjonsson, president of Rapp Marine USA, the domestic arm of the company. He adds that electric has become the mainstay of the unquestionably modern European fishing fleet.
Part of the reason for the switch overseas is that electric components, notably the power controllers, have come down significantly in price. That means a price drop across the board, and suddenly the product is more competitive. Across the board, even among small-boat owners, Europe has decidedly adopted electric.
“Purse seiners in Europe used to only have hydraulics, but now even they are going to electric,” adds Sigurjonsson.
There’s no doubt electric costs more, and there is a learning curve for both the installation and deck crews.
“This is all new to us, we have no other electric winches on our other boats,” says Sewall Maddocks, a quota manager at O’Hara Corp., who worked as the project manager on the Araho construction.
“We went with it for the efficiency. With hydraulic, you lose a certain percent of power as the fluid moves through the lines. With electric, all the power is there; it’s instantaneous.”
For the Araho crew, that meant a learning curve, too, and they traded in the tactile feel of fluids and mechanical feedback in the controls with those that rely totally on electrical contacts. Maddocks says the only way you can tell what percentage of power is engaged is to look at the winch control screen.
At Eastern Shipbuilding, Reeves England and Matt D’Isernia are project managers who worked on the Araho. But Reeves notes that the total electric outfitting of that boat wasn’t a one-off — they have another fish boat under construction using Rolls-Royce electric winches.
Installing these systems is a trade-off at the yard, and “a lot more cable instead of piping has to be installed,” says D’Isernia. “It makes electrical integration all the more fundamental. It’s one thing to get power to a winch using a single wire. Now we have these great big drive contacts and they have to integrate with the ship’s electrical.”
To accomplish this, a certain synergy between the yard, naval architect and system integrator needs to take place, and that takes a lot of upfront design work that England says is perhaps the most critical part of the project.
Sigurjonsson adds that the shipyards might save some of the upfront overhead on reduced installation costs, where wiring is run and connected instead of plumbing that needs to be routed then flushed clean.
The instant power of electric also reduces pressure valves needed on hydraulic systems. This can translate into lower operating costs, since peak power is always on demand, and engines don’t have to work harder to reach the operating RPMs needed to maintain load.
With power transmitted by variable frequency, energy is there no matter the load on the winch. For low-power draws, just the right amount of power is sent and the rest returns to the ships electrical system instead of a bleeder valve used to reduce pressure on hydraulics.
In the case of Araho and the 14 winches installed, a major amount of power needed to be generated, and an innovative solution was engineered.
“The prime mover is the shaft generator,” says D’Isernia.
While a huge 4,000-hp EMD 16-710G7 engine turns the 154-inch wheel, an equally massive shaft that connects the two takes advantage of a 1,700-kW ABB shaft generator. Although unlikely, should this unit fail, two 550-kW Caterpillar C18 generators are waiting in the ready.
The effectiveness of the system is through the Lufkin 7.20:1 reduction gear that slows the shaft down into sub 900-rpm range, an ideal spot for generating the right amount of power for the boat. As the Araho wheel is so big, and the shaft pitch is adjustable, operating speeds as low as 750-rpm can be easily compensated.
As a side note, adjustable-pitch shafts might also become common on new fish boats using electric winches in the near future. Used in other industries, most notably tugs for shipping, these systems were just taking off at the peak of high fuel prices before the market crash lowered fuel operating costs dramatically.
It turns out the shaft isn’t the only place on the boat where power can be generated; the winches themselves need to transfer that power once a brake is employed. In the case of the smaller winches, electric brakes are used, while on the larger winches, air or hydraulic brakes are also used as a fail-safe brake, especially for the big net rigs. When not regenerating power, it’s either burned off into a water-cooled brake resistor, or transferred back into the switchboard for other uses.
Controlling the flow of electricity requires more than just wiring, and that’s where custom software and electronics have their place. The home office in Norway designed and programmed the software used for Araho, and all communicate on the same onboard network. A set of master controls and monitors faces aft on the bridge, but a redundant set also was installed in the forward helm, so the skipper can choose how he wants to control the gear.
Getting all the winches dialed in and the crew familiar with the operation was an arduous task that started in Gulf of Mexico and wasn’t fully realized until the boat reached the fishing grounds.
“We did a few weeks of trials in Florida and then a few weeks of trials in Seattle. The Florida tests looked at the basic functions and looked at the ship’s machinery, propulsion and steering,” says England.
After a three-week transit, which included a trip through the Panama Canal, the Araho arrived at Fishermen’s Terminal in Seattle after a tight fit through the locks in Ballard. In Seattle, the crew installed the trawl doors, and then took the boat back out to deeper water to test how all the winches worked together, notably deploying the nets with the cod ends opened.
Testing also revealed a feature of the electric winches that doesn’t translate from the specifications sheet until an actual experience, and that’s low operating noise. “Part of the learning curve was the quietness; they are very quiet,” says Maddocks.
For new construction, D’Isernia says it’s a relatively small cost to upgrade to electric winches while building a boat like the Araho. But for conversions, it doesn’t often doesn’t make sense. Maddocks, speaking about the rest of the O’Hara fleet that is totally invested in hydraulics, says the cost and complexity to replace the gear would be significant.
And then there are those who are just hesitant to make the switch. Sigurjonsson says some people — mostly small-boat operators — still like hydraulic no matter what because they are comfortable with that system, even though those winches can be converted to electric without nearly the cost of converting a big boat.
“They’re more popular overseas because fishing boats haven’t been built here in forever,” says D’Isernia.
With a fisheries boatbuilding boom about to explode, it’s only a matter of time before finding out if the new American fleet will request electric deck gear the same way as the Europeans.