A grading panel inserted into a net is pulled up for inspection in the new, larger net bay at the W&J Knox premises at Kilbirnie, Ayrshire.

Net supplier Knox gears up to grow with the salmon sector

Firm is introducing innovative new products and has expanded capacity at its Ayrshire base as part of Norwegian parent company’s investment in the future


Scottish net manufacturer and servicing company W&J Knox Ltd has reported great interest in its novel net designs and solutions  during what it said was a reasonable first six months of 2023.

The most recent developments from the Ayrshire company include a glider system that provides improved operational tension of fish pen nets as well as ease of lifting. The system was introduced to Knox through its Norwegian parent company, Selstad AS, and further developed for the Scottish salmonid sector by the Knox engineering team led by Rhuaraidh Edwards, the newly appointed general manager at Knox.

“Matching of component interfaces is key to the success of this project. Our team in Kilbirnie have a wide experience and knowledge base when it comes to this,” said Edwards.

Several sites have successfully trialled the glider system ... one site manager described this as a ‘massive game changer’

Knox general manager Rhuaraidh Edwards

“Several sites have successfully trialled this system, which is due to be rolled out to other locations soon. One site manager described this as a ‘massive game changer’.”

Knox said its net service department is enjoying a busy period following recent investments in a larger capacity crane and Scotland’s first 70 cubic metre net washer and associated wastewater treatment plant. Part of the Kilbirnie factory has also been converted and mechanised to allow stretching out of much larger nets.

Larger nets

The company’s managing director, Finlay Oman, said: “We have an ongoing programme of investments to scale up our entire facility around our customers’ requirement to wash, repair and modify the functionality of larger nets.”

Knox’s manufacturing supply partner, Indian company Garware Technical Fibres, is continuing its programme of netting development. The latest evolution of Sapphire SealPro knotted netting for predation prevention and secure containment is called CFR Flexi. This has an improved mesh breaking strength for the equivalent twine diameter.

Knox said improved results are also being seen with strength to weight ratio, cut resistance and knot stability. The company said it has already brought many cage nets into Scotland made from CFR, with positive comments all round. A variant of this product is also coatable and has undergone successful initial trials and is being expanded to some more challenging locations.

Sustainability projects

Knox is working on several sustainability projects headed up by Ryan Ganfield, who joined the business two and a half years ago with an academic background. His primary focus is to establish multiple recycling routes for end-of-life fish cage nets, to the benefit of the Scottish industry, which led to him being shortlisted in the sustainability category of this year’s Aquaculture Awards.

Ganfield also assists across the Selstad Group on various projects of this type and with Garware Technical Fibres on design of new products.

With the retirement of former Knox managing director Dave Hutchens earlier this year, business development manager Alec Russell has taken on the role of technical adviser on the ‘Lift-Up’ system that removes mortalities from the bottom of fish pens. Knox, like fellow Selstad Group company Isfell in Iceland, has been an agent for Lift-Up since 2016.


Selstad increased global revenue to NOK 1.03 billion last year and is investing in capacity expansion at its net service stations in Norway and Iceland, as well as Scotland.

But profits for its business in Norway were reduced by higher costs and its investment in expansion.

The group’s Norwegian operations (Selstad AS) had a turnover of approximately NOK 625 million in 2022, an increase of just over NOK 50m from the previous year. But the pre-tax profit for the Måløy-headquartered supplier was just over NOK 13m, less than half of the NOK 33m booked in 2021.

“2022 was a demanding year with increased costs for raw materials, logistics and energy. This, combined with fierce competition in the market, resulted in reduced margins for us last year,” said chief executive Hans-Petter Selstad in a press release.

“The result is also influenced by the fact that we have also increased our capacity in 2022 through greater investments in equipment and personnel.”

Salmon tax slowdown

Selstad operates five net service stations in Norway and plans a sixth, in Troms, before the end of the year.

“For the current year, we still see increased activity despite the fact that we operate in a demanding market. The basic interest tax (a 25% extra tax on salmonid farmers’ profits in Norway) clearly slows down investment in the farming industry. We are looking forward to being able to open a new service station in Troms and will continue to invest in our capacity,” said Hans-Petter Selstad.

The Knox team will be travelling to the world's biggest fish farming trade show, Aqua Nor, in Trondheim next week and can be found around the Selstad stand (D370).