Question 515Steam Plants - Assistant Engineer

The correct answer is A) bull gear. The component labeled "IV" in the illustration is the bull gear, which is a large, slow-rotating gear that is part of the reduction gear system in a marine propulsion system. The bull gear transfers power from the high-speed pinion to the low-speed propeller shaft, reducing the rotational speed while increasing the torque. The other answer choices are incorrect because the high-speed pinion (B) is a smaller, faster-rotating gear that meshes with the bull gear, the first reduction gear (C) is the initial stage of the reduction gear system, and the low-speed pinion (D) is a smaller gear that is part of the final stage of the reduction gear system.