Technical Circular No.17 | 2016

Subject: SOLAS Chapter XI-1 Special Measures to Enhance Maritime Safety.

  • IMO vide Resolution MSC.350(92) adopted SOLAS regulation III/ relating to enclosed space entry and rescue drills and entered into force on 1 January 2015.
  • As per MSC 350(92), while carrying out enclosed space entry and rescue drill as per SOLAS regulation III/, carriage of atmospheric testing instrument was not explicit.
  • MSC 380(94) adopted amendments to SOLAS chapter XI-1 introducing new regulation 7- "Atmosphere testing instrument for enclosed spaces" which requires ships to carry an appropriate portable atmosphere testing instrument(s), capable of measuring concentrations of oxygen, flammable gases or vapours, hydrogen sulphide and carbon monoxide, prior to any entry into enclosed spaces.
  • The SOLAS regulation XI-1/7 requires all ships of 500 gross tonnage and above engaged on international voyages to carry portable atmosphere testing equipment/s on board the ship from 1 July 2016.
  • Enclosed spaces are spaces that have limited openings for entry and exit, inadequate ventilation and are not designed for general occupancy. The atmosphere in an enclosed space may be oxygen-deficient or oxygen-enriched and/or contain flammable and/or toxic gases or vapours, thus presenting a risk to life. Enclosed spaces covered by this regulation could among others include cargo spaces, double bottoms, fuel tanks, ballast tanks, cargo pump rooms, cofferdams, chain lockers, void spaces, duct keels, inter-barrier spaces, boilers, engine crankcases, engine scavenge air receivers, sewage tanks and adjacent connected spaces.
  • The selection of portable atmosphere testing instrument for enclosed spaces as required by SOLAS regulation XI-1/7are detailed in MSC.1/Circ.1477.
    • Personnel gas detector that is intended to be carried by individual whilst inside the enclosed space cannot be considered meeting the requirement of portable atmospheric instrument.
    • MSC.1/Circ 1477 (guidelines to facilitate the selection of portable atmospheric instrument for enclosed spaces as required by SOLAS regulation XI-1/7) and Resolution A.1050 (27) (Revised recommendation for entering enclosed spaces on board) do not constitute a performance standard for such equipment.
    • The equipment to be selected and should be as per MSC.1/Circ.1477.
  • Portable gas measuring instrument required by SOLAS or other Conventions/Codes as applicable to the ship type and which also comply with MSC.1/Circ.1477 may be used to satisfy above requirements.


  1. MSC.1/Circ.1477 - Guidelines to facilitate the selection of portable atmosphere testing instruments for enclosed spaces as required by SOLAS Regulation XI-1/7.

  2. A.1050(27) - Revised recommendations for entering enclosed spaces aboard ships.


This Technical Circular and the material contained in it is provided only for the purpose of supplying current information to the reader and not as an advice to be relied upon by any person.
While we have taken utmost care to be as factual as possible, readers/ users are advised to verify the exact text and content of the Regulation from the original source/ issuing Authority.

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