Question 113Motor Plants - Assistant Engineer

The correct answer is B) the angularity of the connecting rod against the crosshead during the power stroke. The side thrust on the crosshead in a large slow-speed propulsion diesel engine is the direct result of the angularity of the connecting rod during the power stroke. As the piston moves down, the connecting rod acts at an angle against the crosshead, creating a sideways force that pushes the crosshead laterally. This side thrust is an important design consideration, as it can cause wear and stress on the engine components. The other answer choices are incorrect because: A) the piston rod acts directly on the crosshead, not against it; C) the velocity of the crank pin does not directly create side thrust; and D) the cylinder pressure acts on the piston crown, not the crosshead.