Question 955 Deck General

The correct answer is D) one half the ullage of the tank and one meter below the tank top. This is the correct answer because the regulations require measuring the oxygen content at two points in a cargo tank - one at one-half the ullage (the empty space in the tank) and one at one meter below the tank top. This ensures that the entire tank volume is checked for proper oxygen content before loading cargo that requires vapor recovery. The other options are incorrect because they do not fully align with the regulatory requirements. Option A checks only the bottom and top of the tank, missing the critical middle section. Option B checks at regular intervals but does not specify the key locations required. Option C checks the bottom and middle, but not the top, which is an essential measurement point.