Watertight Integrity – Amendments to SOLAS Chapter II-1

Watertight Integrity – Amendments to SOLAS Chapter II-1

Amendments to B-1 to B-4 of SOLAS Chapter II-1 were adopted to align criteria for watertight integrity in parts B-2 to B-4 with the probabilistic damage stability approach in parts B and B-1.


Amendments adopted to following regulations:

  • 6.1 to simplify the requirements for any valve which is installed at the collision bulkhead. The amendment does not specify the type of valve (e.g. screw down or butterfly) but instead provides a number of functional requirements.


“The valve shall be remotely controlled valve capable of being operated from above the bulkhead deck of passenger ships and the freeboard deck of cargo ships. The valve shall normally be closed. If the remote-control system should fail during operation of the valve, the valve shall close automatically or be capable of being closed manually from a position above the bulkhead deck of passenger ships and freeboard deck of cargo ships.”


  • Various regulations regarding doors and hatches above the bulkhead deck that might be allowed to be open during navigation have been changed to standardize requirements.


These amendments provide clarity to the requirements and affect the subdivision arrangements and design of vessels.


The amendments are a result of experience with revised SOLAS Chapter II-1 after the probabilistic damage stability approach was introduced in the 2009 update SOLAS.  The approach assesses the probability of survival for a ship in case of damage, related to the extent and location of the damage.  The probabilistic approach is perceived to give a more realistic representation of the condition of a ship in damaged situations, and to allow more freedom regarding, for example, the placement o watertight bulkheads.






  • PMDS surveyors are requested to read the applicable amendments to be familiarized with the requirements.
  • The amendments will apply to new cargo and passenger ships constructed on or after 1 January 2024.
  • Amendments will apply to existing ships only for modification cases for above regulations.
  • Compliance date 1 January 2024
  • Refer to the resolutions:
    • 429(98) Rev. 1
    • 429(98) Rev. 2
    • 474(102)

For additional information contact us : corporate@panamamaritime.com