Question 680Steam Plants - Assistant Engineer

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 will only be capable of reduced speed ahead. This is because the damaged pinion is responsible for transmitting power from the turbine to the reduction gears, which in turn drive the propeller. Without the pinion, the full power of the turbine cannot be transmitted to the propeller, limiting the vessel to a reduced speed ahead. The other options are incorrect because: B) and C) would require the vessel to have additional means of propulsion, such as a separate astern turbine or gear train, which is not the case here. D) is incorrect because the main unit cannot achieve full speed astern without the pinion.