Course stability is one important factor while taking into consideration safety of navigation for towed vessels. Recently, the problem of towing operation, towing equipment etc. has been considered at the design stage.
Course stability will depend on various factors and especially in this paper emphasis has been placed upon the effects of wind on the two towed systems. A theoretical approach to the calculations is also elaborated. Calculations for three different types of systems, composed of cargo and tanker vessels, i. e. for the case when the towed vessels are identical, small and large, large and small respectively, are performed and the effects of wind on each system are as follows.
For higher wind velocity, the above mentioned systems have a tendency to become stable, however as the wind direction changes from the against wind to the following wind, there is a tendency for the systems to become unstable. Besides these, the tow line length, the location of the tow and towed points also influence the stability of the systems.