The Wall, by Tor-Net

Tor-Net has focused on hexagonal mesh pelagic trawl designs since the outset, producing trawl gear for customers around the world.

It’s one of those ideas that’s so obvious that you have to wonder why it hasn’t been done before.

Icelandic trawl manufacturer Tor-Net has adapted its trawl designs by extending the side panels of pelagic gears all the way forward to the doors, closing the gap between the upper and lower sweeps to extend the trawl’s fishing area.

“We call it the Wall,” Tor-Net’s Victor Strange said.

He explained that skippers have told him how they have struggled with jumpy fish, losing them from the area between the doors before they were far enough into the gear opening to be inside the trawl.

The idea of closing the gap seemed like a solution, although it may have seemed like something of a far-fetched one, and the first step was to build a model of Tor-Net’s standard hexagonal mesh 1440m trawl with extended wings. This was tested in the flume tank at Hirtshals and the results were promising enough to take the idea further, this time with an adapted 768m trawl in a Wall configuration for pelagic vessel Major, fishing from Dakhla in Morocco.

“There’s nothing to stop the fish escaping sideways between the sweeplines, so the idea is to close the gap. If you’re fishing at the surface, there’s no way for then to escape upwards, and experience shows that normally the fish want to go sideways to get out of the path of the trawl rather than diving downwards,” Victor Strange said.

The Wall trawl removes the conventional side lines from a standard design and the side panels are braided all the way forward, all the way to the trawl doors, using the same mesh size as in the front sections of the gear and with the sweeplines effectively becoming extensions of the headline and fishing line.

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“For the Wall trawls we have been producing for customers in Iceland who use Dyneema sweeplines, we have kept to Dyneema, but in Morocco where they are fishing close to the bottom in shallow water, the lower sweeps are chain all the way, which contributes to maintaining the gear’s vertical opening,” he said, commenting that on a test trip from Dakhla in Morocco with the 2600hp Major, the usual 768m gear showed a horizontal opening of 70m between the sidelines, with a 110m spread between the doors, so the Wall version extends that fishing area to the spread between the doors instead of the distance between the trawl’s sidelines.

“The 1440m trawl generally fishes with a 130m horizontal opening and a spread between the doors of 200m, so this gives it a fishing spread of an additional 70m,” he said.

“The conclusions were that the gear is no heavier to tow than usual, and there’s an idea that the doors could even be scaled down a size as the long side wings help provide spread. Shooting and hauling were no problem at all, with the gear going straight up onto the net drum as usual.”

“I was concerned that the doors could be skewed,” he admitted, adding that he joined Major for the first trials with the Wall trawl.

“But that wasn’t the case at all. The doors performed as usual and they didn’t seem to be affected. Most of the time they were getting from 50 to 150 tonnes in a haul, and Major has fished well with the Wall, taking 2900 tonnes of mainly sardine in 14 fishing days over a month.”

“The skippers have seen it and they like the idea,” Victor Strange said, admitting that it is still very new and there is still limited experience of the Wall in use. The company has orders for Wall trawls for this summer’s mackerel season in Iceland, with a 1440m Wall for Hoffell and Greenland trawlers Tasilaq and Tumeq have also ordered 1248m and 960m Wall trawls for this summer.

Looks promising

Skipper Helgi Ágústsson said that Major is new to fishing in Morocco, recently acquired by Silver Food to supply its production facilities, primarily canning mackerel and sardine for export.

Built as Geysir in Denmark in 1979, it passed into Norwegian ownership as Ligrunn and operated solely as a purse seiner before being bought by Silver Food and converted back to a trawler as the Major, including fitting a pump system so the fish can be pumped aboard at the stern instead of over the side.

It now fishes from Dakhla, mainly on sardine and mackerel. Helgi Ágústsson said that the initial trip with the Wall was a sardine trip and catches were favourably comparable to those of the boats fishing around them.

“The crew were so positive that they were happy to switch the gear over so we could have the Wall on the starboard drum where it’s easier to handle, and we used it for the whole trap, apart from a couple of tows.”

“We weren’t catching any less and my feeling was that we generally did better than most with this gear, and there’s plenty of interest from other skippers in what we were doing,” he said, commenting that the next trip, after a stopover for drydocking in the Canaries, will be interesting as he expects to start targeting mackerel that hug the bottom more than the sardine that can be higher in the water and which tend to keep to tight shoals.

“The thinking behind the Wall is similar to adding long bridles to a bottom trawl to herd the fish more efficiently,” he said.

On sardine, they often fish at depths of only 35-40m, so the trawl virtually fills the available space.

“You can see the footrope just off the bottom and the sweepline legs hitting the surface, so there’s nowhere for the fish to escape upwards or downwards,” he said.

“We’re fishing mackerel at this time of year, April-May-June-July and even into August at 65-80m depths, almost scraping the bottom. In winter the mackerel shift northwards to 90-130m. We don’t normally get the big bags of mackerel that we can have with sardines. But it’s a shoaling fish, and it can happen,” he said.

Major’s fishing activities are managed to fit in with the parent company’s production requirements, so trips are short – frequently no more than 24 hours – and the skipper has to watch the codend sensors carefully to not overload the gear.

“Tow length depends on the catch. If there’s nothing making its way into the gear and the codend sensors haven’t indicated anything, then it’s all right to lengthen the tow. But if there’s fish in the bag early in the tow, then we’ll keep it short.”

“The main difference shooting way is taking care to keep straight, so the sounder cable stays between the wings and doesn’t have a chance to tangle with the wing meshes. But handling the gear hasn’t been any more of a problem than it usually is, it just needs  a little care as the gear is shot away until the kite squares it and the wings start to spread.”

“It promises great things and I’m optimistic that this is going to work very well,” he said.

Dakhla outlet

“Now we’re opening a store in Dakhla in Morocco and have taken on Hadre Mahfout to run it. Close to 90% of the pelagic fleet in Dakhla is using our gear now so we need to be able to supply them with spares and gear,” Victor Strange said.

“Often we are supplying trawlers with the complete package of trawl, codends, sweeps, warps and doors, and even hoses for pumping the fish on board, so it’s time that we were able to offer this in Dakhla itself. The store carries all the equipment the boats need, although we’re not producing gear there. That will continue to be done in Iceland or at Las Palmas and we can ship from the Canaries to Agadir and from there the gear is trucked south to Dakhla.”

Big gear

The mainstay of the two net lofts’ activities remains the hexagonal mesh trawls that Tor-Net revived and updated with modern materials, and the company is busy with orders for this year.

“Huginn is now using one of our 2208m trawls for blue whiting and did well on the first trip a long way south in the international zone west of Rockall before heading up to Faroese waters to continue the season there,” Victor Strange said.

“They’re getting a 210m by 110m opening with this trawl, squaring it with a pair of 15m2 doors and and 160m sweeplines with a warp tension at the winch of around 20 tonnes.”

Faroese pelagic vessel Tróndur í Gøtu is using a Tor-Net 2400m trawl for the same fishery, also using the same gear for pairing on mackerel.

“We’ve been busy with these big trawls and we’re also supplying gear for Royal Greenland Pelagic for mackerel, plus our customers in Iceland have been coming to use for the summer mackerel season.”

“These are trawls that we’re now making in overbraided Super-12 rope that is manufactured for us by Euronete. They produce, splice and overbraid the bars to standard lengths and we can use these to assemble the gear using Dyneema connectors to construct the meshes.”

He explained that this is the standard Super-12 that Euronete has produced for some years, but the PE overbraiding is done to Tor-Net’s specifications, giving the bars a stiffness that is not lost with use.

“We’re using this for the big meshes in the front sections, and this is better for the crew as well as making shooting the gear easier. These are long meshes and the bars are easier to handle. As the bars are stiff, there is less chance of tangling as the gear is shot, so there are fewer delays getting the gear into the water and less chance of lost time,” he said, adding that the bars are made with colour coded flecks in the overbraid, red and green for port and starboard, as well as blue for upper panels and white for the lower panels.