Question 368Steam Plants - 1st Asst/Chief

The correct answer is A) provide reduction gear tooth inspection. The jacking gear on main propulsion turbines is used to manually rotate the turbine shaft, allowing for inspection of the reduction gear teeth. This is an important maintenance and safety procedure to ensure the proper functioning of the reduction gears, which transmit power from the turbine to the propeller. The other answer choices are incorrect. Option B is incorrect because the jacking gear is not used to provide propulsion in emergencies. Option C is incorrect as the jacking gear is not used to reduce turbine speed during maneuvering. Option D is incorrect as the jacking gear is not used to lift the reduction gear casing.