News from Thyborøn Trawldoor
Last year Thyboron Trawldoor introduced the “Flipper” doors, as a technical design change of the existing Type 15 VF. This year we moved this design change with its adjustable foils to our Type 14 VF.
The world patented “Flipper” trawldoors with adjustable foils from Thyborøn Trawldoor change their type numbering. The new Type 20 VF “Flipper” is based on the Type 15 VF and the new Type 21 VF “Flipper” is based on the popular Type 14 VF.
Four adjustable foils were added to the classic blue flying trawldoors resulting in the new “Flipper” trawldoors. Now you can have two sizes of trawldoors in one.
With the four adjustable foils, we are able to reduce the spreading power up to 17 % and the door’s water resistance up to 24 %. Changing the angle of attack allows for further reductions. Reducing the spreading power to such a degree makes it is possible to use the same doors for different types of fisheries: Trawling with full size doors / closed foils after e.g. blue whiting and trawling with reduced size doors / open foils after herring and mackerel.
Since the introduction of the Type 20 VF “Flipper”, it has been tested with great success in the Netherlands, Denmark, Greenland and Iceland.
Two sets of 13m² Type 20 VF “Flipper” are in use in the Netherlands at the company Cornelis Vrolik on F/V “Carolien” and at the company W. van der Zwan on F/V “Alida”. Both vessels are using them for blue whiting, herring and mackerel fishery
A set of 8.5m² Type 20 VF “Flipper” is in use on the trawler HG 306 Tobis in Denmark. The trawler is twin rigging for shrimp in the North Sea with closed foils. When the trawler is twin rigging for cod and saithe all the foils are open to reduce the spreading power.