What is the correct position of the shut-off valves for the last trailer of a doubles or triples set?
A. Fully closed
B. Fully open
C. Partially open
D. Emergency shut-off valve open; service shut-off valve closed
The correct answer is: Fully closed. Shut-off valves (sometimes referred to as cut-out cocks) are located at the back of trailers used to tow other trailers. All valves
should be in the open position except on the last trailer which should be in the closed position.