Abstract
Marine debris washed ashore causes serious environmental effects. It is both effective and efficient to catch and collect floating debris before it reaches shore. In this study, the authors examined a system to catch and collect marine litter floating on sea. The system is composed mainly of a floating fence, a towing line and a towing ship. The floating fence, which is laid without mooring on the sea current as the drifting debris, consists of a floating body, a catching net, and a n underwater brake. The underwater brake decelerates the floating fence drift speed so that floating debris can be caught and collected. The shapes and conditions of the floating body and catching net were selected based on the results of model basin tests in waves. The floating fence drift speed was estimated by considering the resistance characteristics of the floating fence obtained in model tests. Finally, the transportation and recovery system of the collected garbage was designed using a pusher-barge system.
