🔍 Key Concepts

• Contamination risk to turbine bearings and lube oil coolers from using seawater directly • Typical shipboard central cooling systems for sensitive equipment (gas turbines, electronics, lube oil) • Separation between main turbine lube oil and reduction gear lube oil systems

💭 Think About

• Which cooling medium would engineers avoid routing near fine turbine bearings because of corrosion and contamination? • Does the illustration (and your shipboard experience, if any) suggest that the turbine lube oil cooler ties into a shipwide cooling loop, or into the reduction gear system? • Is hot compressed bleed air a sensible choice for cooling oil, or is it normally a heat source?

✅ Before You Answer

• Eliminate any option that would increase risk of salt contamination in the turbine lube oil system. • Ask whether the turbine and reduction gear normally share one common lube oil system or two separate, independent systems. • Confirm which system on most gas‑turbine ships supplies cooling to sensitive equipment: central seawater directly or a freshwater cooling loop cooled by seawater.