ENCLOSED SPACES (PERMIT TO WORK)
· Permit to work form must be used for any jobs which might be hazardous.
· It states work to be done and safety precautions.
· Safety instructions are written down and given to persons associated with the job.
· The permit should contain a checklist to identify and eliminate hazards plus arrangements for emergency procedures in case of any accidents.
· The permit should be issued by a responsible officer and must ensure that all checks have been properly carried out and signed only when he is satisfied that it is safe to work.
An enclosed space will include cargo tank, ballast tank, cofferdam, bunker tank, fresh water tank, duct keel etc., which may contain toxic vapours or insufficient oxygen to support life.
No one must enter an enclosed space without first obtaining permission from the Proper Officer.
Before making entry the following to be checked and approved by the Master.
1. Spaces to be visited.
2. Names of all personnel entering.
3. Details of communication system.
4. Anticipated time of completion of entry.
5. A proper communication system using portable VHF sets. ( communications to be effective between the OOW on the bridge and the person immediately outside the space).
O2 Analyser - oxygen deficiency
Explosimeter - measures explosive limits
Tank Scope - measures oxygen in inert atmosphere
Dragger Tubes - measures oxygen if correct tube fitted (also measures the presence of various toxic gases).
· Ventilation (either forced or natural) to be carried out before entry is permitted.
· If forced ventilation is used then minimum of two air changes must take place.
· If potentially dangerous spaces allow for between 10-20 air changes per hour.
· If natural ventilation is only available space must be allowed to “breathe” for atleast 24 hours prior entry.
· Full ventilation may be ensured by filling the tank with clean sea water and pumping out to ensure fresh air enters the space. (This should be coupled by forced ventilation).
· No one must enter a cargo pumproom without the permission of the Proper Officer.
REQUIREMENT FOR ENTRY INTO PUMPROOM
· A permanently rigged rescue line and harness should be at the top of all cargo and transfer pumprooms (part of life saving appliance) (SHOULD NOT BE USED FOR ANY OTHER PURPOSE).
· No fixed equipment fitted in the pumproom should be operated if the gas LEL is in excess of 40%.
· Gas generation caused by oil in bilge’s may be reduced/minimised by spreading a layer of foam over the pumproom bilge’s.
· Permission has been obtained from a Senior Officer.
· Ventilation should be provided for at least 15 minutes and remains in use throughout the period of entry.
· Means of communication must be established.
· Lifeline and Harness is ready for immediate use.
· A competent person is standby on top of the pumproom to call for assistance.
· Advice the officer of entry and exit.
· Obtain explosimeter reading from the Bottom platform that it is free of toxic vapours along with regular checks (incase of maintenance works)
· At least one compressed B.A set is ready for immediate use on top. (in case of maintenance works)
· Additional B.A set is ready for use close at work. (incase of maintenance works)
· Have resuscitation equipment ready for immediate use close at work. (incase of maintenance works).
· Chief Officer should personally supervise incase of an emergency.
THE OXYGEN CONTENT OF AIR IS 21%. IF THE LEVEL FALLS TO APPROXIMATELY 17% THE ATMOSPHERE IS UNSAFE.
SAMPLE OF AN ENTRY PERMIT FORM
1. Has the permission been obtained from the Chief Officer?
2. Is the tank clean?
3. Is the tank pressurised?
4. Has the tank been inert, then gas-freed?
5. Does the tank atmosphere contain at least 21% oxygen?
6. Is the hydraulic cargo system shut down?
7. Is the tank isolated from the inert gas main?
8. Have notices been placed at tank hatches?
9. Have notices been placed at the inert gas isolating valves?
10. Have notices been placed on the cargo control?
11. Is fresh air being supplied to the tank?
12. Is one man stationed at the cargo tank hatch?
13. Is breathing apparatus and a lifeline available?