What is the criteria for securing the main lube oil pump after securing the MRG?

The criteria for securing the main lube oil pump after securing the Main Reduction Gear (MRG) is that the lube oil temperature must be within 10 degrees F of the engine room ambient temperature. This is important because maintaining a temperature close to the ambient level indicates that the lube oil has sufficiently cooled down. Running the pump when the oil is still too warm can lead to issues such as increased viscosity, which can hinder proper lubrication and potentially cause damage to the bearings and other moving parts in the system. Therefore, ensuring that the temperature is within the specified range helps to protect the equipment and maintain its longevity.

Other factors, such as the lube oil level or pressure gauges, while relevant in operational scenarios, do not specifically address the thermal conditions that must be met before securing the pump after the MRG is shut down.