- Any space that has been closed and unventilated for some time
- Any space contaminated by cargo or leaking through a bulkhead, pipeline or cargo residues in the cargo pump.
- Any space because of cargo carried contained harmful gases
- should always suspected in an enclosed space that cargo residues may remain on the internal surface of the tank even after cleaning and ventilation.
- Any space which may be deficient in oxygen
- should always suspected in all an enclosed space particularly if they have contained water, have subjected to damp, or connected with other inerted tank
Example of an enclosed space onboard
- Ballast tank
- Cargo tank
- Double bottom
- Fuel oil tank, etc.
Many fatalities onboard tankers have resulted from entering the space without proper supervision. And in almost every cases the fatality would have been avoided if the guidance had been followed.
Atmosphere test prior to entry an enclosed space
- Any decision to enter should only be taken after the atmosphere has been tested from outside with test equipment that has recently been calibrated and checked for correct operation.
-Essential that all atmosphere testing equipment used are;
- Suitable for test required
- An approved type
- Correctly maintained
- Frequently checked against standard sample
- Maintenance work and calibration test, period of the validity should be record
- Testing carried out only by personnel who have been trained in the use of the equipment in other word competent person.
-Enclosed space should not be entered without correct authorization from ship master or officer in charge. As per CSWP entry should made under a ‘permit to work’ system or monitored by a safety checklist