Question 23Motor Plants - 1st Asst/Chief

The correct answer is C) allow piston cooling water to efficiently enter the piston despite its reciprocating piston motion without contaminating the engine lube oil. Telescopic pipes attached to water-cooled pistons of large, slow-speed, main propulsion diesel engines are designed to allow the piston cooling water to enter the piston effectively while it is in motion, without the cooling water contaminating the engine's lubricating oil. This design prevents the mixing of the piston cooling water and the engine's lubricating oil, which would be detrimental to the engine's operation. The other answer choices are incorrect because they do not accurately describe the primary purpose of the telescopic pipes. Option A is incorrect as the telescopic pipes do not overcome crankcase pressure. Option B is incorrect as the telescopic pipes are not designed to prevent excessive lubricating oil temperature. Option D is incorrect as the telescopic pipes are designed to prevent the contamination of the cooling water, not the other way around.