The permit-to-work system

The permit-to-work system is an important operational safety measure in industries with severe hazards. It aims at ensuring that work is planned and carried ont under adequate safety precautions in cases where the exposed persons do not control the relevant energies themselves. 

Example 1 An installation worker should remove a flange during the commissioning of a process plant. He started by mistake to work on a system that was under pressure due to leak testing. When he had removed some of the bolts, the others were ripped off and the flange came flying and hit his leg. The leg was lost. 

Example 2 An instrument operator should mount a vibration gauge on a pump. While the man was doing the work, the pump was started from the control room. The rotating shaft caught his arm and he was severely hurt. 

An important safety principle behind the permit-to-work system is to ensure that the relevant parts of the system are de-energised during work in the danger zone. The challenge lies in designing and implementing a procedure that is simple and robust and that covers all relevant situations. 

The padlock system to avoid electrocution is a simple example. The electrician has his own padlock, which he uses to secure the main switch in a safe position and thereby de-energises the electrical system before he starts to work on it. 

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Are staff trained in the use of the permit-to-work system and its significance ... 

The root causes for this critical event both concern the operations department and the service department who ran the contractor maintenance team. The operations department (i.e., the day shift operations supervisor) failed to provide adequate supervision and instructions to the contractor team. Explanations of the nature of the permit-to-work systems (i.e., the need to report back at end of shift) should have been given, and the possibility and implications of work not being completed before the end of the shift should have been considered by both parties. 

Permit to work program. The basic training will include a thorough explanation of the permit to work system, including lockout/tagout, hot work procedures, and vessel entry procedures. The training should focus on the interface between operations and maintenance. It is essential that the operator trainee knows where the lines of responsibility lie. 

An important part of the permit to work system is the isolation of sources of hazards and energy before maintenance, repair or other activities requiring a permit are carried out. Such hazard and energy sources are ... 

The permit-to-work system must help communication between everyone involved in the process or type of work. Employers must train staff in the use of such permits and, ideally, training should be designed by the company issuing the permit, so that sufficient emphasis can be given to particular hazards present and the precautions which will be required to be taken. For further details see Permit to Work at www.hse.gov.uk. 

Statistics reinforced the preconceived idea that maintenance activities have an element of danger. A British publication by the Health and Safety Laboratory (2003) [1] stated that maintenance activities accounted for about 15.6% of all the 718 loss of containment incidents that were reported This study collected data over a period of 11 years. Of 112 loss of containment incidents that were attributed to maintenance activity, 57 were classified having do to with procedures (or the lack of them) or improperly implementing the existing maintenance procedures. Of 112 loss of containment incidents 37 were attributed to the permit to work system [1]. 

Cullen noted many deficiencies in the Permit to Work system on Piper Alpha, including the lack of any consistent practice of physically locking-off isolated equipment, and the absence of a review or discussion of permits at shift handover. 

Manage the permit to work system for hot works > Ensure effective arrangements for liaising with the fire service and other emergency service prior to and at the time of an incident. 

The permit to work system is more fully described in Chapter 8 specifically as it relates to the control of hot work. 

Ymer s platform management faces a number of SHE challenges, especially dnring the first period after start-np. The organisation is new and unfamiliar with the platform and the management system. Construction work on the platform has not been fully completed at start-up and continues in parallel with production and drilling. It is of major importance to avoid construction work on systems that have not been de-energised. Here, the permit-to-work system plays an important role. 

The documentation is reviewed yearly to identify the need for updating. Job-safety analyses are always performed before the start of new jobs that may be critical from a safety point of view. The supervisor reviews the need for such analyses as a routine procedure in the permit-to-work system. The following types of jobs have to be assessed in a job-safety analysis before they can start ... 

The conclusions are rather serious. Ymer s management has not adequately foreseen the SHE challenges involved in carrying out modifications in parallel with ongoing production. There is a need to upgrade the permit-to-work system so that it can handle a much higher activity level. Systematic risk assessments must be performed on all modification work and procedures need to be established on the basis of the results. 

Is it checked that the permit-to-work system is adequate for the needs during the tie-in of new systems to the existing plant and during commissioning and start-up of new systems ... 

Safety related activities should be properly planned to ensure that they can be carried out safely and effectively. Suitable and sufficient assessments of the risks to health and safety arising from particular activities should be carried out. The nature of the required risk assessment will depend on the extent of the risks involved and may be qualitative or quantitative in nature. The purpose of the risk assessment is to identify the acceptability of the proposed activity and the appropriate contfol measures required to ensure that risks are as low as reasonably achievable (ALARA). The results of the risk assessment should be incorporated into work instructions or control documentation associated with the activity, for example, the documentation for the permit to work system. 

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