Dynamical response characteristic of warp tension and ship's motions while towing a trawl net.

The authors considered the towing system of a trawler as consisting of the ship body, towing warp, trawl net and otter boards. In order to effectively control this system, it is necessary to know the characteristics of its dynamical response to waves, based on the dynamical relation between the ship's motions and the warp tension. For this purpose, experiments were performed using a self-propelled model of a 124 GT trawler 2 meters long and two kinds of fishing gear.The results were analyzed and discussed. It was noticed that the dynamical relation between the ship's motions and the warp tension was the most important factor in relation to the twoing system of a trawler engaged in a fishing operation.