Coast Guard Exams
Question 359Steam Plants - 1st Asst/Chief70% to pass

While a vessel is underway the low-pressure turbine high-speed pinion is damaged. The pinion is then removed from the gear train. Under these circumstances, the main unit is capable of which speed and direction?

AI Explanation
The correct answer is A) Reduced speed ahead only. When the low-pressure turbine high-speed pinion is damaged and removed from the gear train, the main unit is only capable of reduced speed ahead. This is because without the high-speed pinion, the gear train is no longer able to transmit the full power of the turbine to the propeller shaft, limiting the vessel's speed. However, the vessel can still move forward at a reduced speed, as the remaining components of the propulsion system are still functional. The other options, such as reduced speed astern or full speed in either direction, are not possible without the intact high-speed pinion.