Question 1 of 2921866636ef128f7522a1c521b34

While a vessel is underway, the low-pressure turbine high-speed pinion of the main reduction gears is damaged. After the damaged high-speed pinion is removed and the main engines are placed back into operation, what would be the speed and direction capability of the main propulsion engines?

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Question 1 of 29218
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While a vessel is underway, the low-pressure turbine high-speed pinion of the main reduction gears is damaged. After the damaged high-speed pinion is removed and the main engines are placed back into operation, what would be the speed and direction capability of the main propulsion engines?

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🔍 Key Concepts

• Double-reduction main reduction gears and how high-speed and low-speed pinions share the load • How steam (or gas) turbine main propulsion trains split power between ahead and astern elements • What happens to available power and gear train capability when one high‑speed pinion in the ahead train is removed

đź’­ Think About

• Is the damaged low‑pressure turbine high‑speed pinion normally used for ahead power, astern power, or both? • If one high‑speed pinion in the ahead train is removed, can the remaining turbine and gear elements still provide some ahead or astern thrust, and in which direction would the train be structurally complete? • Think about which direction (ahead vs astern) usually has less power capability in turbine plants, and how losing one part of the ahead train would affect maximum usable speed in each direction.

âś… Before You Answer

• Identify which turbine(s) and pinion(s) drive the ahead gear wheel versus the astern gear wheel in a typical main reduction gear setup • Verify whether the astern turbine usually has its own pinion and gear path separate from the low‑pressure ahead high‑speed pinion • Confirm which direction (ahead or astern) would be limited to reduced speed if one of the ahead high‑speed pinions is removed from the gear train