Currently at the stage of evaluating the new concept using computer flow dynamics, Norwegian company ECO Trawl has developed a set of ideas that are aimed at replacing trawl doors with steerable propulsion units.
According to ECO Trawl’s general manager Mads Bjørnenak, the venture started in Kristiansand in 2016 with the intention of drawing on experience in offshore technology to make trawling more efficient and more environmentally friendly.
A central pillar of the concept is using steerable thrusters instead of trawl doors, shifting the towing power needed to tow the trawl from the catching vessel to the fishing gear itself, effectively turning the trawl into a remotely operated vehicle.
ECO Trawl’s concept contains largely existing technology from the offshore sector – which is where Mads Bjørnenak and the ECO Trawl team have their background.
While a fishing vessel deploying its gear opened with ECO Trawl’s thrusters would not need the engine power that a conventional trawler needs, it would still need to generate the electrical power supplied to the thrusters via high voltage cables, either with a bank of generators or from a shaft generator on board.
‘Two to three hundred metres is not that much of a distance for high voltage,’ he said, adding that the main element that requires specialised development is the control system for the thrusters, with a wired control link alongside the power delivery.
‘Most of the technology already exists,’ he said. ‘The motors, propellers, nozzles and cables are almost available off the shelf, but we are putting these into a new package. We expect to have to produce propellers and nozzles in new sizes, but this is still all known technology.’
‘This technology enables the trawl to be closer to the vessel, almost directly aft of it,’ he said.
‘When the trawl is directly aft of the vessel there is a shorter distance from the echo sounder beam to the trawl and shorter time from when you actually see something on the echo sounder until the trawl passes. This means that the trawl can be steered more accurately and quickly than before.’
Go to the latest issue of Hook & Net for the full story on ECO Trawl.
