USCG Exam PracticeMaintenance, machine tools, drawings, and tables
During steam turbine operation, loss of lubricating oil pressure is treated as a trip-level casualty. Which combination of factors makes this the correct response?
- ✓ High turbine speeds and small blade-to-casing clearances mean a bearing will fail within seconds without oil flowCorrect
- B. Loss of oil pressure causes the gland sealing steam system to fail, admitting air into the condenser vacuum
- C. The overspeed trip cannot function without oil pressure to actuate the steam admission valve
- D. Loss of oil pressure causes uneven rotor heating, which bows the shaft and triggers the low-vacuum alarm
Why A is correct
NAVEDTRA 14104 §5-2 states that because clearances are small and speeds high, a turbine depends absolutely on continuous, clean, cool lubricating oil; loss of lube-oil pressure is a trip-level casualty because a bearing will fail in seconds. The other options conflate separate protective systems described in the same source.
Cited:NAVEDTRA 14104 §5-2