What are the benefits of water lubricated stern tubes?

At MIT we champion environmentally sound sustainable solutions for our customers. We understand that careful consideration is required to apply the right solutions to a given application and operating profile. Once installed we support our customers throughout the operational life of the equipment.

One area that we have a good deal of experience in is stern tube seals and bearings. When matched to a suitable application, a seawater-lubricated system is the optimum environmental solution for a vessel’s stern tube. This solution can provide high reliability and minimum maintenance; in addition, the risks of aft seal damage and oil loss to the marine environment are completely removed.

Previously one of the disadvantages of seawater lubrication over oil for classed vessels was the necessity for regular tail shaft withdrawal inspections, which require additional time and expense in dry dock. As is widely known, special notations now exist within most major class societies’ rules to allow for an extended or indefinite period between tail shaft withdrawal inspections for water-lubricated stern tubes. In general the various society’s rules aim to manage the risks by stipulating specific design requirements, condition monitoring and in situ inspection.

At MIT, we can support vessel owners with condition monitoring along the entire drivetrain, including providing inspections of the stern tube. One such project was recently completed in Hamburg for a leading cruise vessel operator. Our experienced engineers visited the vessel while it was in dry dock to conduct an in situ stern tube wear measurement and shaft liner borescope inspection. When the inspection was completed and the data was collected and collated, the examination revealed that the water-lubricated system was in excellent condition. In fact, as part of our report, a prediction was made on the expected remaining wear life of the bearing. The data indicated that the bearing was about halfway through a predicted wear life and would likely exceed the vessel’s life. This is an excellent example of the right solution providing the owner with a fantastic return on investment and MIT being there to support our customers.

Talk to us today about how we can support you with condition monitoring and in situ inspections worldwide.