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

Under USCG National Maritime Center examination standards, the accepted correct answer is: allow piston cooling water to efficiently enter the piston despite its reciprocating piston motion without contaminating the engine lube oil.