What method is commonly used to lubricate main propulsion turbine reduction gears?

The most effective method for lubricating main propulsion turbine reduction gears involves spraying oil through nozzles at the point of gear mesh. This approach ensures that the oil is directly delivered to the areas where friction and wear are most likely to occur, specifically at the gear teeth where they make contact during operation.

This method has distinct advantages, including minimizing the amount of oil needed and maximizing the effectiveness of lubrication, leading to improved wear protection and cooler operation. Spraying oil also allows for a more uniform distribution across critical contact surfaces, which is vital for reducing metal-to-metal contact and extending the lifespan of the gears.

While other lubrication methods such as pouring oil directly into the sump, circulating oil through a closed-loop system, or manual injection may have their applications, they do not target the gear mesh as effectively or may not provide the same level of immediate lubrication to the most critical areas of the reduction gears. Using nozzles to spray oil takes advantage of precision and efficiency, proving to be the most suitable option in this context.