|Equipment Class: Fishing technology||Equipment Type: Gear handling|
|Triple roller is a multiple power hauling system where the net is hauled by means of a synchronized triple roller net winch system known under the commercial name "triplex".|
Triple rollerTriple roller winch system or triplex
The triple roller net winch hauls the net simultaneously through three synchronously powered rollers. The central roller turns in the opposite direction to the other two. The rollers are tiltable in the vertical axis to allow the position of the floatline on the rollers to be changed. The hauling speed of the floatline can be increased by lowering the rollers towards the horizontal. The floatline will then slip outwards to a thicker part of the roller. To reduce the hauling speed of the floatline the rollers are angled upwards, leading the floatline onto a smooth and thinner part of the roller. There the floatline slips, thus reducing its speed in relation to the rest of the net. By further increasing the tilt, the floatline can be brought onto the main part of the rollers and be hauled at the same speed as the net.
The main advantage of a multiple power hauling system is that the main net hauling machine is mounted well forward and at a relatively low height. This make it easier to manoeuvre the purse seiner, particularly (European seiners) with the net well away from the vessel's stern and propeller and, with transverse thruster, eliminates the need for power skiff.