UK publishes the Damage Stability SOLAS 2020 Amendments with explanatory notes

UK Maritime and Coastguard Agency on April 25, 2023, published the Damage Stability SOLAS 2020 Amendments with explanatory notes.

The basis text in this document is extracted from the SOLAS Consolidated Edition 2014, which incorporates all SOLAS amendments in effect from July 1, 2014.

Of particular importance is the December 2006 Annex 2 amendments, adopted by IMO resolution MSC.216(82), which came into force for passenger ships and dry cargo ships with keels laid on or after January 1, 2009.

These amendments, known as the SOLAS 2009 amendments, significantly revised SOLAS 90 Part 1 Chapter II-1 Parts A (General), B (Subdivision and Stability), and B-1 (Subdivision and Damage Stability of Cargo Ships).

Chapter II-1 was reorganized and revised as follows:

  • Part A, titled "General," saw substantial revisions to regulations 1 and 2 on application and definitions.
  • Part A-1, related to the structure of ships, remained unchanged.
  • Parts B and B-1 underwent complete changes. A new Part B, consisting of a single regulation 4, introduced sub-paragraphs on application, alternative methodologies, degree of subdivision, and the effectiveness of subdivision. The previous regulations 4 to 7 regarding the determination of subdivision for passenger ships using floodable lengths, factor of subdivision, margin line, etc., were entirely removed. Regulations 8, 8-1, 8-2, and 8-3, which dealt with the deterministic assessment of damage stability for passenger and ro-ro passenger ships, were replaced by new probabilistic regulations and placed in a new Part B-1 under the heading "Stability."

Part B-1 now contains subsections on intact stability and the provision of stability information to the master, along with the integrated probabilistic regulations for passenger and dry cargo ships.

The old dry cargo ship probabilistic subdivision and damage stability regulations, as well as the provision of stability information to the master, were harmonized into the new Part B-1.

It's essential to note that the probabilistic damage stability regulations in the SOLAS 2009 amendments (Chapter II-1 Part B-1 regulations 6, 7, 7-1, 7-2, and 7-3) apply to internationally trading passenger ships of all sizes and dry cargo ships with gross tonnage ≥ 500 and a length of 80 (or 100) meters and above, which do not already comply with subdivision and damage stability regulations in other IMO instruments listed in the new Part B.

Other regulations in new Parts B-1, B-2, B-4, and C (35-1) are applicable to all passenger and dry cargo ships with gross tonnage ≥ 500 constructed on or after January 1, 2009, unless otherwise specified.

Furthermore, several amendments were made to SOLAS 2009 after January 1, 2009.

These amendments, known as the SOLAS 2020 amendments, are applicable to passenger and dry cargo ships constructed on or after January 1, 2020. Amendments to the accompanying explanatory notes were also made and appeared in IMO Resolution MSC.429(98).

The amendments and explanatory notes are highlighted accordingly in this guidance document.

Please note that this text represents a condensed summary of the original document.

For the complete and official information, refer to the SOLAS Consolidated Edition 2014 and subsequent amendments and resolutions adopted by the IMO.


For more information, please see the documents below (available only to subscribers):


Damage Stability SOLAS 2020 Amendments with explanatory notes

MSC.216(82): Amendments to the International Convention for the Safety of Life at Sea, 1974, as Amended

MSC.429(98)/REV.2: Revised Explanatory Notes to the SOLAS Chapter II-1 Subdivision and Damage Stability Regulations