Question 7 AT01 - Assistance Towing Endorsement

The Correct Answer is D **Explanation for D (Correct Answer):** When towing, the connection between the tug and the towed vessel (or object) is subject to sudden changes in tension caused by waves, changes in speed, or course adjustments (known as 'snatch loading' or shock loading). A wire hawser (steel cable) is strong but has very little elasticity (stretch). If a direct connection were used, these sudden shocks could easily exceed the breaking strength of the cable or severely stress the towing points. A chain bridle (or spring/surge chain) is introduced specifically to act as a *spring* or *shock absorber*. The weight and the natural sag/catenary curve of the heavy chain allow it to stretch or lift slightly under sudden strain, absorbing the shock and cushioning the load before the full force is transferred to the less elastic wire hawser. **Explanation for Incorrect Options:** * **A) It does not chafe:** While the chain itself is highly resistant to chafe, this is not the *main* operational reason for its use in this specific setup. Chafe protection for the wire hawser is usually achieved through chafing gear or specific fairlead designs, not primarily by the bridle itself. * **B) It eliminates the necessity of a swivel:** A chain bridle does not replace a swivel. Swivels are necessary to prevent the wire hawser from twisting under load, particularly during long-distance tows where the towed vessel might yaw or the wire is spooled incorrectly. The function of the bridle and the swivel are separate. * **C) It makes for an easy connection:** While connecting the hawser to the chain bridle might be straightforward, the primary function of the heavy chain bridle is related to shock absorption and load distribution on the towed vessel's bitts, not merely ease of connection. Other, lighter materials could be used if ease of connection were the only goal.