Abstract
When a large vessel is approaching to a berth or a wharf, the support of tugboat is indispensable for it to be controlled in safety, such as stopping and berthing control. However, assisting forces produced by tugboat, especially the braking force, have been scarcely examined and little data on the proper characteristics of the braking force can be obtained. Therefore, it is necessary to investigate the braking performance of tugboat. In this paper, the braking force characteristics of tugboat-self in braking condition are obtained and the related unstable phenomena is pointed out and analyzed according to the results of model experiments. Furthermore some new understanding on the braking co-operation by using tugboat is suggested.
