ROV tool to repair fish cages

Abstract

This thesis deals with one of the main challenges the aquaculture industry is facing today: escapes from fish cages. To avoid or limit the impacts of such events a Remote Operated Vehicle (ROV) mounted tool is proposed and designed. This tool can fix the damaged nets rapidly before escapes can occur. The use of smaller ROVs is growing in the aquaculture industry and this thesis proposes combining an ROV as an observational platform and a repair platform. After evaluating two different methods for the repair, one with the use of cables ties and the other with steel wire, a prototype is described, designed and evaluated. How the tool should be mounted on the ROV depends on the maneuverability of the ROV. Therefore, the degrees of freedom of the chosen ROV is important and addressed in this study. A simulation of the drag coefficient of the tool is carried out to evaluate its characteristics in the water, followed by calculations to determine the necessary performance of the actuators in the tool. The finished design and prototype is functional and shows promise.