The stern shaft sealing device is a key equipment in the main propulsion system of a ship

The stern shaft sealing device is one of the key components of a ship’s main propulsion system. For vessels using oil-lubricated stern shaft seals, oil leakage caused by fishing nets entangling the stern shaft during navigation occurs frequently. In minor cases, immediate dry-docking is required; in more serious cases, oil pollution may lead to hefty fines imposed by port state authorities, resulting in significant direct economic losses. Furthermore, the operational downtime of the vessel also leads to considerable commercial losses. For a long time, this issue has been a persistent challenge in the shipping industry, one that has yet to be completely resolved. The following is an overview of our company’s experience and perspective on addressing this issue, which we hope will contribute to solving this long-standing problem.

Except for water-lubricated stern bearings, all oil-lubricated aft stern bearings must be equipped with a sealing device. There are mainly two types of sealing devices: radial seals, such as the J0-type skeleton seal and the German Simplex 0-type seal; and face seals, such as the Swedish Cedervall 0-type seal and the Deep Sea Seals 80-type seal from the United Kingdom.