Question 15 TK01 - Tank Vessel Assistant - Dangerous Liquids

The Correct Answer is A. **Explanation for Option A (Final topping off is occurring):** Final topping off (or "stripping") is the most critical time during bunkering because the rate of flow is typically reduced significantly, and the tanks are nearly full. If the flow is not managed precisely or if communication fails, the margin for error is extremely small, and the risk of the tank overflowing onto the deck (a "bunker spill") is at its absolute maximum. This phase requires intense attention from the bunkering crew, monitoring tank levels minute by minute, often switching flow to the final tank, and coordinating the final stop with the supply vessel. **Why the other options are incorrect:** * **B) Hoses are being disconnected:** While there is a risk of a small residual drip or spill when disconnecting hoses, modern equipment (quick closing couplings, drip trays) is designed to minimize this hazard. This is a manageable localized spill, whereas a tank overflow during topping off (A) results in a massive, widespread spill. * **C) Hoses are being blown down:** Blowing down (using compressed air or nitrogen to clear residual fuel from the hose) is done under controlled procedures, usually back into the delivering tanker's system. Although it requires attention, the risks associated with pressurized systems are generally lower and more manageable than the risk of exceeding tank capacity inherent in topping off. * **D) You first start to receive fuel:** When starting to receive fuel, the flow rate is slow, and the tanks are empty, providing maximum capacity and a large margin for error. The primary focus is checking lines and connections for leaks. While important, it is not the **most critical** time for an accidental pollution incident compared to the final minutes when the tanks are full.