Experimental study on the course stability of a towed barge model

Abstract

The course instability problem of towed objects is discussed in the paper. It is noted that many non-selfpropelled vessels do not have directional stability, as a result of which they make oscillatory movements relative to the course of the towing ship. Increased yaw rate leads to a decrease in towing speed, an increase in loads on the elements of the towing device and a significant increase in the width of the running lane. These factors can lead to an emergency and significantly complicate the towing process, especially on inland waterways. Two main ways to increase directional stability are considered. These are towing “on V-line”, that is a system in which the towing rope is divided into two parts and attached to two points of the towed barge, located symmetrically relative to the centerline, and the installation of skegs in the stern. To determine the effect of these methods, tests of a model of the mixed riversea navigation oil barge 2731 are carried out in calm deep water conditions in the experimental tank of the Admiral Makarov State University of Maritime and Inland Shipping. The root end of the towing rope is attached to the pylon of the towing tank trolley and, thus, the reverse influence of the barge on the characteristics of the tug movement is not taken into account. Sixteen options are considered. The half-width of the running lane is taken as a criterion for the stability of barge movement. As follows from the test results, with increasing towing speed and towing rope length, the width of the running lane increases slightly. The installation of end washers on the skegs has no effect on the stability of the barge. To reduce the width of the running lane occupied by the barge, it is recommended to use towing “on the V-line” and use skegs with fixed flaps.