Document ID: chunk:federal_register_of_legislation:F2018L01173:body:0:p36
Version: federal_register_of_legislation:F2018L01173
Segment Type: other
Provision Reference: 
Character Range: 93232–95907

times against unauthorised entry. Signs should also be erected at each entry to warn against unauthorised entry.
A door or hatch cover which is opened to provide natural ventilation of a confined space may, wrongly, be taken to be an indication of a safe atmosphere. Therefore the use of a mechanical barrier, such as a rope or chain positioned across the opening with an attached warning sign, could prevent such accidental entry.
Care should be taken to avoid the effects of a possible release of pressure or vapour when opening the entrance to the space.
Flammable vapours may still be present in cargo or other tanks that have contained oil products or chemical or gas cargoes. Cofferdams and other spaces that are adjacent to cargo and other tanks may contain flammable vapours should there have been leakage into the space.
Hydrocarbon gases or vapours are flammable as well as toxic and may be present in fuel or cargo tanks which have contained crude oil or its products. The gases or vapours may also be present in pump rooms and cofferdams, duct keels or other spaces adjacent to cargo tanks due to the leakage of cargo.
The space should be isolated and secured against the escape of dangerous substances by blanking off pipelines or other openings, or by closing valves. Valves should then be tied, or some other method used to show that they must not be opened.
The space should be cleaned or washed, if necessary, to remove as much as possible of the sludge or other deposit liable to give off dangerous fumes. If an empty tank or other confined space has been closed for a time the oxygen content may have been reduced.
The space should be thoroughly and continuously ventilated by natural or mechanical means, to ensure that all harmful gases are removed and no pockets of oxygen-deficient atmosphere remain. Compressed oxygen should not be used to ventilate any space. All persons in the space should leave immediately if the ventilation system fails.
Officers on watch, or persons in charge, on the bridge, on the deck, in the engine-room, or the cargo control room should be informed as necessary that a space is to be entered so that, for example, fans are not stopped, equipment not started or valves not opened by remote control.
Appropriate warning notices should be placed on the relevant controls or equipment.
If necessary, pumping operations or cargo movements should be suspended when entry is being made into a dangerous space.

7.4              Procedures and arrangements before entry
Access to, and lighting within, the space should be adequate.
Sources of ignition should not be taken into the space.
Persons entering enclosed spaces should be