# The Merchant Shipping (Cargo Ship Construction) Regulations 1997, Regulation 45: Closing of openings Requirements for tankers constructed on or after 25th May 1980 and to other ships constructed on or after 1st September 1984.

Extent: E+W+S+N.I.

(1) In every ship the number of skylights, doors, ventilators, openings in funnels for exhaust ventilation and other openings, to machinery spaces shall be the minimum compatible with the proper working and safety of the ship.
(2) The skylights to machinery spaces of Category A shall be constructed of steel and their flaps shall be capable of being closed and opened from a suitable position outside the space in the event of fire. Adequate arrangements shall be made to permit the release of smoke in the event of fire.
(3) Windows shall not be fitted in machinery space boundaries. This requirement shall not preclude the use of glass in control rooms located within the machinery space boundaries.
(4) Any machinery space of Category A which is accessible from an adjacent shaft tunnel shall be provided with a light-weight steel fire-screen door in addition to any water tight door. The fire-screen door shall be operable from each side and shall be located at the shaft tunnel side of the bulkhead.

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Source: https://www.legislation.gov.uk/uksi/1997/1509/regulation/45 (the official version)
Page: https://openlegislation.uk/merchant-shipping-cargo-ship-construction-regulations-1997/regulation-45
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.