New materials – new possibilities

When designers at Faroese fishing gear manufacturer Vónin were looking for a new braided rope to replace the Euronete Super-12 that has long been their mainstay in making the large meshes of its pelagic trawls, they went to the Portuguese manufacturer with their ideas and requirements.

“A few years ago we started using overbraided twine, but we weren’t sure that simply overbraiding standard Super-12 was the answer,” Jógvan S. Jacobsen of the company’s pelagic gear division said.

 

“There are plenty of factors to take into consideration, including hardness and softness. If it’s braided to hard, then the twine becomes too heavy and this also pushes up the price.”

 

He explained that getting just the right qualities is a balancing act and after a lot of experiments, Euronete came up with Capto, a version of Super-12 with a PE cover that meets all of the requirements and without sacrificing any of the qualities of Super-12 that has served well for many years and which is still in regular use alongside the new product.

 

Capto is manufactured in port and starboard red and green colours, yellow for the top sheet and in blue for the lower panels, all with white flecks, and with the blue rope also manufactured with a lead content to provide negative buoyancy and to help open the gear.

 

Unlike the traditional arrangement of ordering ropes and splicing these at Vónin’s net loft in Fuglafjördur, instead the company has sought a different solution from Euronete.

 

“When we have an order for a trawl with the front sections made in Capto, we send an inventory of the materials needed, including the number of individual bars to Euronete, who supply these measured, spliced and overbraided.

 

“We connect the bars with a 6 or 8mm Dyneema rope connector looped through the eyes of four bars and tied securely,” he said.

 

 

The new Capto rope’s dimensions is larger than conventional Super-12 as the overbraiding adds slightly to the bulk, but the rope also maintains a rounder shape.

 

As a result, a trawl made in Capto looks bulkier on a net drum, partly due to Capto rope being a stiffer material.

 

“There is no change in the gear’s performance, and in developing this new rope we weren’t looking for something that would fish more effectively, as the trawls already catch well as they are.

 

“Instead, we were looking for ease of handling for the crew and a longer working lifetime. So far we have found that this material is very stable. But it’s still very new and if the trawls fish better with it, then that’s a bonus.”

 

Groundfish breakthrough

 

According to Søren Havmand, a new Dyneema-based netting made for Vónin by Euronete has been something of a breakthrough in groundfish gear, solving problems encountered when Dyneema netting becomes soft with long use.

 

“We went to Euronete to formulate something new and the solution was to make the twine with a core,” he said, explaining that the core of a twine is normally where the strength lies, but Dyneema’s strength makes this unnecessary.

 

“Usually twine has a strong core with a protective jacket. But as the Dyneema is also so abrasion resistant, we felt we could use a core that provides stiffness, while relying on the Dyneema in the jacket to give it its strength,” he said.

 

The result is Fortis, a Dyneema-based netting with an integral stiffness that is not lost with extended use, and bolstered by a heat treatment that also ensures additional twine stiffness.

 

This is a new product that has been thoroughly trialled, with two years of hard use on shrimp and a year’s use on groundfish to give it the exhaustive testing required, also with some unexpected results.

 

He said that initially Fortis was thought to be ideal for shrimp gears with small meshes and high resistance, and it was almost a surprise when simulations indicated that it would make a significant difference to Bacalao fish trawls with 160-200m meshes.

 

“This wasn’t just the bellies. It also made a big difference in the wings, so we started making these trawls in Fortis throughout. It made these trawls are much, much lighter to tow.”

 

Norwegian trawler Atlantic Star has successfully switched from its old twin 500 mesh trawls to a pair of 630 mesh Bacalao trawls for twin rigging and a single 850 mesh trawl to replace its 720 mesh gear for saithe, made possible by the opportunities offered by the Fortis netting.

 

“The owners of another Norwegian trawler, Ole-Arvid Nergård, came to us with a problem as they were struggling on saithe due to propeller noise frightening the fish away whenever the pitch went over a certain level, so they needed a trawl that was light enough to tow at a propeller pitch of less than 60%,” Søren Havmand said.

 

 

“So we designed a pair of trawls that put them back on saithe, and since then they have ordered two more trawls.

 

This is what Fortis has made possible, allowing us to redesign gear for better size or spread and height, but without needing bigger doors or burning more fuel,” he said, adding that these trawls have been especially successful on saithe and Greenland halibut.

 

“There’s so much cod in Norwegian waters at the moment that you don’t need anything special to catch it, but it’s a different story with saithe and Greenland halibut.”

 

He said that customers in Greenland were looking for shrimp trawls with more wing spread and height, while keeping their doors and fuel bills unchanged.

 

“This new netting has made this possible,” Søren Havmand said. “We were able to redesign the existing 3900 mesh trawls by adjusting cutting rates and hanging ratios in ways we would not have been able to with existing materials.”

 

“The result is trawls that are easier to spread and which lift higher that we couldn’t have produced in older materials.

 

“Initially this was a project with Royal Greenland, but now the whole fleet there has switched to these trawls made with Fortis.”