Propeller Shaft Inspection Kamsar
The propeller shaft passes through the stern tube, which is sealed to keep seawater out and lubricating oil in. If the seal fails, oil can leak into the sea or water can enter the stern tube, harming bearings and the shaft. A propeller shaft inspection in Kamsar lets an owner check the external parts of this system without dry-docking.
What a Diver Can See
A Diver can examine the propeller cone, the hub, the area around the aft seal and the visible parts of the shaft. Signs of oil leakage appear as a film or staining around the seal, and rope or netting wrapped around the shaft can damage seal faces. The Diver also checks that the propeller nut and cone are secure and that there are no cracks or corrosion at the hub.
Typical Findings
- Oil or grease staining at the aft seal, indicating possible leakage.
- Fishing line, rope or plastic wound between the propeller and the seal.
- Corrosion or erosion at the cone, hub or shaft.
- Loose or missing cone bolts and locking devices.
- Damage to the seal housing after contact with debris.
Why Environmental Compliance Matters
Oil leakage from stern tube seals is an environmental and regulatory concern, and many ports and charterers pay attention to it. Detecting a leak early allows the ship to correct it before it becomes a violation. Where the ship uses environmentally acceptable lubricants, owners still wish to avoid losses. A documented inspection shows that the ship was checked and that any leak was dealt with promptly.
Wear-Down and Clearance Checks
On some ships, a stern tube bearing wear-down measurement is part of the class requirement. Some measurements, such as poker gauge readings, can be taken from inside the ship, while some external checks can be made by a Diver. Where the class surveyor requires underwater confirmation of the shaft position or clearances, our team will follow the procedure agreed with the surveyor and the ship's engineers.
Clearing Entanglements
Rope or net around the shaft is a common cause of seal damage. A Diver can cut away the material using sharp tools, taking care not to damage the seal face. We photograph the shaft before and after, and we advise the engineers if signs suggest that the seal needs attention.
Arrange a Shaft Inspection
Contact us with your concerns, and we will plan the dive with the engineers.
Why Early Seal Checks Save Money
Replacing a stern tube seal normally needs dry-docking, so owners want to extend seal life as much as possible. Early detection of rope damage, oil staining or scoring allows a quick response and may avoid a larger failure. A regular underwater look at the aft seal area, combined with oil consumption monitoring in the engine room, gives a strong early warning. The cost of a short inspection is small compared with an unplanned dry-docking.
Shaft Earthing and Corrosion Checks
Besides the seal, a Diver can check the shaft earthing device and the condition of exposed shaft sections. A poorly earthed shaft can suffer electrical erosion of the bearing surfaces, while exposed shaft surfaces can corrode where coating or sleeves are damaged. We photograph the visible parts and note any signs of pitting, staining or damage, and we pass the findings to the chief engineer. These checks add little time to the dive but give the engineers early warning of problems that are otherwise only visible in dry dock. They also help to plan spare parts and the next maintenance window.
Frequently Asked Questions (FAQ)
Q1. What is the stern tube seal for?
It keeps seawater out of the stern tube and lubricating oil in, protecting the shaft and bearings.
Q2. How can a Diver detect an oil leak?
By visual signs of oil film or staining around the aft seal, and by checking for rope or damage that could cause leakage.
Q3. How long does a shaft area inspection take?
Typically 1 to 3 hours, depending on visibility and any entanglement to clear.
Q4. Can bearing wear be measured underwater?
Not usually. Wear-down is normally measured from inside the ship. A Diver confirms external condition and seal area.
Q5. How often should the shaft area be checked?
Many owners check at each underwater survey, normally every 6 to 12 months, and after any rope or net entanglement.