​Consideration has been given to work being carried out from outside the confined space and has been considered not to be feasible.  The following safe system of work must be adhered to as it has been developed from the risk assessment carried out.

• ​1. All pipelines to and from the vessel will be isolated by means of spectacle blinds and any internal mechanical or electrical equipment will be isolated and locked off, (see piping and instrumentation and electrical drawings for locations).
  
  
• 2. A check will be made to ensure that the vessel is securely earthed to ensure any static electricity is discharged safely.
  
  
• 3. The drain valve will be opened and facilities put in place to contain all residues washed out of the vessel. (Identify means of disposal.)
  
  
• 4. The drain valve will be opened and facilities put in place to contain all residues washed out of the vessel. (Identify means of disposal.)
  
  
• 5. The vessel will be opened by removing all covers and vented to atmosphere by means of an external air blower fan and supply hose.  Care will be taken to ensure that the atmosphere being discharged is clear of any sources of ignition or incendive sparking. (Identify location.)
  
  
• 6. The external air blower fan will provide forced ventilation at all times to ensure the level of oxygen is maintained and a comfortable working temperature.
  
  
• 7. Care will be taken regarding the location of the blower to ensure it draws in no contaminants.
  
  
• 8. The interior will be washed down using high pressure washers and detergent, paying special attention to the base of the vessel where hydrocarbon sludge or residue may collect. (As for item 3.)
  
  
• 9. A portable gas detector will be tested in the open air to ensure it is functioning and then the atmosphere in the vessel will be tested for residual hydrocarbon gas and oxygen content. This operation will be carried out from the outside using a probe attached to the intake of the instrument. (Identify type of gas detector.)
  
  
• 10. Emergency escape equipment will be positioned and tested, in readiness, prior to a confined space permit to work being issued. (List types of equipment.)
  
  
• 11. Two trained individuals will undertake the work, they will be familiar with and understand the hazards and control measures identified by the risk assessment. They will have been suitably trained and authorised for confined space work. (Name the individuals and cross refer to the confined space permit)
  
  
• 12. They will be familiar with the emergency escape equipment and be wearing personal protective equipment (PPE) suitable for the work to be carried out. One will be on standby outside the vessel and the other will enter the vessel to carry out the work. (List types of PPE.)
  
  
• 13. The operative entering the vessel will wear a harness attached to a lifeline and hoist.
  
  
• 14. Suitable low voltage explosion proof lighting will be provided to illuminate the interior of the vessel while work is being carried out.
  
  
• 15. The operatives will be in radio contact with each other at all times.
  
  
• 16. On ensuring that all conditions of the permit to work for confined spaces entry have been met. The confined space permit will be issued by the relevant Line Manager or Supervisor who must be familiar with the conditions of work.
  
  
• 17. The operative entering the vessel will take the portable gas detector with him into the vessel along with the emergency breathing apparatus.
  
  
• 18. In the event of an audible alarm signal from the portable gas detector he will don the emergency breathing apparatus and leave the vessel.
  
  
• 19. In the event of the operative inside the vessel not responding to radio contact or not appearing after the alarm from the portable gas detector has sounded, a rescue attempt will be made by the standby man after the alarm has been raised using the pre-programmed mobile phone to summon the emergency services.
  
  
• 20. On completion of the work, the operative will leave the vessel.
  
  
• 21. The work completion section of the confined spaces permit to work will be filled in and the permit handed back to the supervisor for cancellation.
  
  
• 22. The drain will be closed, the entry manhole closed and all isolations removed ready for the vessel to be put on line.

NB. In the event that the work is not completed within the time identified by the confined space permit to work, the operative will leave the vessel and the means of access/egress will be secured to prevent any unauthorised entry until a new confined space permit has been issued.