Damage Stability of Ro-Ro Passenger Ships (SOLAS 2020)
SOLAS 2020 applicability follows three alternative triggers; regular services to or from EU ports also engage Directive 2003/25/EC as amended by Directive (EU) 2023/946.
Operational Explanation
SOLAS 2020 is determined by three alternative triggers: building contract from 1 January 2020; absent a contract, keel/similar stage from 1 July 2020; delivery from 1 January 2024. For regular services to or from EU ports, SOLAS and the EU regime apply cumulatively under the relevant limb, not as a binary choice.
Regulatory Reference
SOLAS Chapter II-1, SOLAS 2020 amendments, adopted by resolution MSC.421(98) of 15 June 2017 and in force since 1 January 2020: increase in the required subdivision index (R) and recalculation of the survival factor (s-factor) for flooding scenarios in the vehicle spaces/large open spaces of Ro-Ro passenger ships, at a global standard level comparable to the 1996 Stockholm Agreement. Regulation II-1/1 on application was amended by res. MSC.436(99) of 24 May 2018, also in force from 1 January 2020: the two resolutions must be cited together. The test for application is the one in regulation II-1/1.1.1, and there are three alternative conditions: “for which the building contract is placed on or after 1 January 2020”; or, in the absence of a contract, “the keel of which is laid… on or after 1 July 2020”; or “the delivery of which is on or after 1 January 2024”. Any one of them suffices. And the regime is not confined to ro-ro ships: it applies to all passenger ships, and to cargo ships of 80 m in length and upwards for regulations 6 to 7-3.
Scope of Application
Check all three SOLAS triggers. For the EU regime distinguish new/existing ship, service after 5 December 2024, any prior certification under the Directive and capacity above or not above 1,350 persons.
Procedure / How to Complete It
- Test building contract, keel/similar stage and delivery; one relevant trigger is sufficient.
- Apply the resulting international SOLAS regime.
- For regular EU-port service classify new/existing, entry date, prior certification and 1,350 threshold.
- Apply the amended Directive 2003/25/EC limb without reducing it to the original Stockholm Agreement.
Practical Example
A ship delivered on 10 January 2024 meets the delivery trigger even if the other dates are earlier. If entering regular EU service, also determine the EU limb from status, date, prior certification and capacity.
What Typically Goes Wrong
Common Mistakes Mistake Library
| Mistake | Consequence | How to avoid it |
|---|---|---|
| Applying the operational load limits of a sister ship with a different keel-laying date, assuming the stability regime is identical | Exceeding the specific ship's real operational limits, with a reduced damage stability safety margin | Always verify the applicable stability regime based on your own ship's specific keel-laying date, not that of a sister ship |
| Structural modifications to vehicle spaces not followed by a reassessment of the damage stability calculation | Stability documentation no longer representative of the ship's actual configuration | Always reassess the stability calculation in the event of structural modifications that alter the subdivision or vehicle spaces |
What the PSCO Checks
Operational Tips
- Know your ship's exact keel-laying date: it determines which damage stability regime applies, not the delivery or entry-into-service date.
- Do not assume a sister ship automatically shares the same stability regime: always verify the specific keel-laying date.
- Coordinate every structural modification to vehicle spaces with a reassessment of the damage stability calculation.
Preparation checklist
- Three SOLAS triggers checked
- International regime determined
- EU service checked
- New/existing and entry date identified
- Prior certification and 1,350 threshold checked
FAQ
Related Topics
Last substantive revision of this page: 19 August 2026 · page fingerprint 885acc09f4bf