Operational guide · Operational procedure

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.

SOLAS 2020damage stabilityRo-Ro passenger shipsStockholm Agreement

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, without automatic equivalence to every limb of the EU regime. 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.

Under the EU regime, keel/equivalent stage before 5 December 2024 makes a ship existing; others are new. The threshold is certified persons, including crew. New ships: above 1,350, SOLAS 2020 II-1 part B; up to 1,350, a choice of Annex I section A or B. Existing ships introduced into service after that date and never certified under the Directive: above 1,350, a choice of SOLAS 2020 or section A plus SOLAS 2009; up to 1,350, section A or B. Ships already in service by that date continue under the previous Annex I. Check certification and national implementation. Directive (EU) 2023/946, Articles 2 and 6 as amended.

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

The MV Estonia disaster, in which the loss of the bow visor caused rapid flooding of the vehicle deck and the sinking of the ship with the loss of more than 850 lives, remains the reference case that motivated both the 1996 Stockholm Agreement and, more than two decades later, the global raising of the standard with SOLAS 2020.

Common Mistakes Mistake Library

Mistake	Consequence	How to avoid it
Determining the regime from keel date alone or from a sister ship’s date	A vessel caught by the delivery trigger or another SOLAS 2020 trigger may be classified incorrectly	For the specific ship, verify all three alternative triggers: building contract, keel laying or equivalent stage, and delivery
Structural changes to vehicle spaces without reassessment	Documentation no longer represents the actual configuration	Reassess the calculation after changes affecting subdivision or vehicle spaces

What the PSCO Checks

PSCOs may check consistency among approved documentation, configuration and operating limits. Applicability of the SOLAS 2020 regime must be demonstrated against all three alternative triggers, including delivery from 1 January 2024, together with any applicable EU regime.

Operational Tips

Collect the building contract, keel-laying or equivalent-stage date, and delivery date: any applicable alternative trigger is sufficient.
Do not transfer a sister ship’s classification automatically.
Coordinate every structural change with reassessment of the approved 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

Does keel date alone determine the regime?

The keel/equivalent-stage limb applies only in the absence of a building contract. A contract from 1 January 2020 and delivery from 1 January 2024 remain alternative triggers; keel date is not an unconditional third test. MSC.436(99).

Did SOLAS 2020 replace the EU regime?

No. Services within the Directive also follow the applicable EU limb.

Damage Stability of Ro-Ro Passenger Ships (SOLAS 2020)

Operational Explanation

Regulatory Reference

Scope of Application

Procedure / How to Complete It

Practical Example

What Typically Goes Wrong

Common Mistakes Mistake Library

What the PSCO Checks

Operational Tips

Preparation checklist

FAQ

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