Tail Shaft Survey
Propeller-shaft survey method, interval, withdrawal and any extension follow UR Z21 as incorporated in class Rules; condition monitoring creates no autonomous CMS tail-shaft regime.
Operational Explanation
Propeller-shaft survey method, interval, withdrawal and any extension follow UR Z21 as incorporated in class Rules; condition monitoring creates no autonomous CMS tail-shaft regime.
Regulatory Reference
IACS UR Z21 and applicable Classification Society Rules.
Scope of Application
Shaft type, lubrication/sealing arrangement, monitoring, results and Rules determine method/interval; Machinery Continuous Survey is distinct.
Procedure / How to Complete It
- Identify shaft arrangement and Z21 method.
- Check due date and withdrawal requirements.
- Collect oil analysis, bearing temperature and seal records where required.
- Use monitoring for modified method/extension only if Rules allow.
- Obtain surveyor acceptance before omitting withdrawal.
Practical Example
Quarterly oil analysis may be required evidence, but alone does not replace the due propeller-shaft survey.
What Typically Goes Wrong
Presenting Continuous Machinery Survey/CMS as an autonomous choice to avoid shaft withdrawal or using one five-year cycle.
Common Mistakes Mistake Library
| Mistake | Consequence | How to Avoid It |
|---|---|---|
| Presenting Continuous Machinery Survey/CMS as an autonomous choice to avoid shaft withdrawal or using one five-year cycle. | Non-compliant decision or treatment | Follow the approved arrangement and applicable sources |
What the PSCO Checks
Operational Tips
- Separate current requirement, class/maker, SMS and voluntary guidance.
- Do not improvise tests, thresholds or intervals.
- Record deviations and corrective action.
Preparation checklist
- Z21 method
- Arrangement
- Due date
- Monitoring conditions
- Surveyor acceptance
FAQ
Related Topics
Last substantive revision of this page: 31 August 2026 · page fingerprint 26b7bcc46570