Last year Thyborøn Trawldoor introduced the ‘Flipper’ doors, as a technical design change to the existing Type 15 VF - this year the company has moved this design change with its adjustable foils to its Type 14 VF.

The world patented Flipper trawldoors from Thyborøn 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 and allowing customers to have two sizes of trawldoors in one.

Type 20 VF Flipper (15 VF)
With the four adjustable foils, the doors 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 - for example, trawling with full size doors/closed foils for blue whiting and trawling with reduced size doors/open foils for 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 to fish for blue whiting, herring and mackerel.

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.