On the marine gas turbine engine as shown in the illustration, the main lube oil system is cooled by ________. Illustration GT-0017

Correct Answer: Option B — reduction gear lube oil

The lube oil system utilizes a heat exchanger where the gas turbine lube oil is cooled by the reduction gear lube oil. This integrated cooling approach simplifies the auxiliary system architecture by using the existing reduction gear cooling loop to manage the thermal load of the turbine bearings.