Telescopic pipes which are attached to water cooled pistons of large, slow-speed, main propulsion diesel engines are designed to ________.

Correct Answer: Option C — allow piston cooling water to efficiently enter the piston despite its reciprocating piston motion without contaminating the engine lube oil

Telescopic pipes provide a dynamic, sealed fluid pathway that supplies cooling water to reciprocating pistons of large slow-speed engines while completely preventing the contamination of the engine crankcase lubricating oil.