The ‘Secrets’ Behind Stern Shaft Seal Maintenance

The stern shaft sealing device is divided into forward and aft sealing units. The purpose of the forward seal is to prevent lubricating oil in the stern tube from leaking into the engine room, while the aft seal prevents both the leakage of lubricating oil into the sea and the ingress of seawater into the stern tube, which could emulsify the lubricating oil. Before the introduction of stern shaft sealing devices, ships equipped only with traditional oil seals often experienced large-scale oil leakage. Such leakage not only caused failure of the main shaft oil seals but could, in severe cases, pose a safety risk to the entire vessel.

If technicians install an additional stern shaft sealing device alongside the oil seal, similar failure issues can be effectively avoided. With this auxiliary component, ships using large-scale oil seals could potentially save a significant amount in annual maintenance costs.