Certain aspects of the present disclosure generally relate to the field of geophysical surveying and may have particular applicability to components used in marine settings.
In geophysical prospecting in a marine environment, sources and receivers of various types are used to understand the geography of the earth below the water. In a typical surveying configuration, the sources and receivers are towed by cables behind a vessel. The cables are typically maintained in relatively fixed orientations to provide clear interpretation of the results. A common method of maintaining the orientations of the cables is to attach them to a spreading device that extends laterally between the cables. Deflectors at the end of the spreading device, commonly called paravanes, provide an outward force as the assembly moves through water, to keep the spreading device extended.
The paravanes are often attached to the vessel using ropes or cables. In some cases the paravanes may be 10 meters or more in length. At times, forces on the paravanes, for example from rough seas, may produce a towing force on the ropes or cables used to tow the paravanes that exceeds a tolerance strength of the rope or cable. In some cases the forces may be of short duration, but damage is done to the rope or cable nonetheless. A technique is needed for managing stresses on ropes and cables used to tow paravanes for marine geophysical acquisition.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation.