Question 69 ONC02 - Second Mate/Third Mate Unlimited Tonnage

The Correct Answer is B **Explanation for B (15%):** The stud, or stay, placed transversely across the center of a chain link (forming a stud-link chain) serves two primary structural purposes: 1. **Prevents Distortion and Collapse:** It maintains the link's shape under high tension, preventing the sides from collapsing inward and the ends from opening up (a phenomenon known as "nipping"). 2. **Distributes Load:** By holding the shape, it ensures the load is borne uniformly, preventing localized high-stress concentrations at the crowns (ends) of the link. Standard maritime and engineering calculations demonstrate that the addition of the stud typically increases the breaking strength and Proof Load of the anchor chain link by approximately **15%** compared to a common or open-link chain made from the same material and dimensions. **Why other options are incorrect:** * **A) 10%:** While close, 10% underestimates the standardized increase in strength and Proof Load attributed to the stud. Classification societies (like ABS, Lloyd's Register) rely on the higher 15% figure when calculating the minimum breaking strength requirements for stud-link chain vs. open-link chain. * **C) 20%:** This significantly overestimates the structural benefit derived solely from the stud. While 20% might be achievable in very specific, optimized designs or under certain test conditions, the conventional, accepted engineering standard for the strength increase provided by the stud is 15%. * **D) 50%:** This is a drastic overestimate. A 50% increase in strength would require a substantial change in material quality or diameter, not just the addition of a simple stabilizing stay (stud).