Question 66 ONC03 - Master LT 500-1600 GRT

The Correct Answer is A. ### 2. Explanation for Option A ("Lashings are always required") When securing a stack of containers using **non-locking fittings** (such as stacking cones or certain types of bridge fittings that do not resist upward lift forces), these fittings primarily serve to prevent horizontal movement (sliding) and ensure alignment. They offer little to no resistance against the significant vertical (uplift) and tipping forces generated by the ship's rolling and pitching, even under normal weather conditions. Because containers are heavy and have a high center of gravity, instability and tipping are major risks. To meet international safety standards (like the IMO's Code of Safe Practice for Cargo Stowage and Securing (CSS Code) and cargo securing manuals), supplementary lashings are mandatory **from the first tier up** (i.e., upon placing the second container in the stack, or the first container if it is not secured by locking fittings to the deck) to provide the necessary redundancy and resistance against dynamic forces. Therefore, lashings are required regardless of how short the stack is. ### 3. Explanation for Incorrect Options * **B) One container, C) Two containers, and D) Three containers:** These options are incorrect because they suggest a threshold height (one, two, or three containers) below which the stack is stable enough to be secured *solely* by non-locking fittings. Since non-locking fittings do not provide adequate resistance against tipping and uplift forces, waiting until the stack reaches a certain height before adding lashings would compromise safety and violate standard cargo securing practices. Lashings must be applied immediately when using non-locking fittings to ensure the stack is secured against dynamic motion.