Dry Dock Scheduling for Sister Ships (Sister Ship Scheduling)
Evidence from a sister ship can improve the next docking, but every data point and work item must be revalidated against the individual ship’s configuration, condition, due dates and history.
Operational Explanation
Ships in one series may share drawings, equipment and failure modes, but modifications, operation, corrosion, incidents and survey history create differences. The previous ship’s dossier is an input to risk review, not a scope to copy.
Staggering can support learning, but actual sequence depends on individual due dates, yard availability, commercial requirements and risk. HSSC does not impose one identical “five-year cycle” on every sister ship.
Regulatory Reference
Each ship retains its own certificates, windows and survey status under applicable statutory instruments and Rules. Fleet management and reuse of lessons learned are Company processes, not a separate IMO regime.
Risk assessment within the safety management system considers the ship’s actual conditions. To apply this principle across a fleet, use a matrix recording the first ship’s finding, equivalent component, differences, required verification, responsible person and outcome on the second ship. This is a Company working tool, not a mandatory IMO form. IMO: ISM Code.
If a finding may compromise safety, assess verification on other affected ships promptly rather than automatically waiting for their next docking. Record the technical decision and any temporary measures in the Company system; update the repair specification with the evidence obtained.
Scope of Application
Fleets with ships of a common or similar design. Reuse depends on design identity, modifications, equipment, operating profile, age, condition and documented history.
Procedure / How to Complete It
- Compare design baseline, modifications, equipment and survey status.
- Transfer findings as hypotheses to verify on the next ship.
- Adapt scope, quantities, spares and criteria to individual condition.
- Plan sequence around due dates and actual constraints.
- Record confirmed, unconfirmed and ship-specific lessons.
Practical Example
Corrosion found on the first ship triggers a targeted inspection on the second. Renewal enters the scope only after evidence or as a priced option, considering the second ship’s own coating history and thickness.
What Typically Goes Wrong
Common Mistakes Mistake Library
| Mistake | Consequence | How to avoid it |
|---|---|---|
| Specification copied | Scope over or understated | Revalidate every item |
| Fixed sequence | Due dates or capacity ignored | Optimize within individual constraints |
What the PSCO Checks
Operational Tips
- Use a difference matrix across ships.
- Separate common and ship-specific findings.
- Retain evidence of verification on each unit.
Preparation checklist
- Design and modifications compared
- Individual survey status checked
- Findings revalidated
- Scope adapted to condition
- Lessons tracked
FAQ
Related Topics
Last substantive revision of this page: 15 September 2026 · page fingerprint fe37fe2920c5