What is a permit to work (PTW) system on ships?

<p>A permit to work system on ships is a formal written control that a responsible officer issues for hazardous or non-routine jobs, such as enclosed space entry, hot work and electrical isolation, after the risks are assessed and precautions confirmed.</p>A permit to work is a formal, written control system used aboard ship for hazardous or non-routine work, built on the simple principle that a dangerous job should never start on the strength of a verbal go-ahead alone, only after its specific risks have been assessed and the necessary precautions confirmed in place and checked by someone other than the person doing the job. It is issued by a responsible officer, typically the chief officer or chief engineer for their respective departments, to the person or team carrying out the work, and it describes the task, the location, the hazards identified, the controls required, and the time period for which it is valid.

Permits are used for the categories of work where accidents most often happen: entry into enclosed spaces such as tanks, cofferdams and void spaces; hot work such as welding, gas cutting and grinding, which needs a fire watch, cleared combustibles and often continuous gas monitoring; work on electrical systems, which needs proper isolation, lock out and proving dead before anyone touches live equipment; work aloft or over the side, which needs harnesses, lifelines and a stand by person; and work on pressurized, energized or otherwise stored-energy systems, where isolation has to be physically confirmed rather than assumed.

The permit ties the individual precautions together into one accountable document. Before it is signed, a risk assessment specific to the job has to have been carried out, isolations completed and tagged, and where relevant the space tested and certified safe by gas measurement covering oxygen, flammable gas and toxic gas as appropriate; a fire watch or stand by person is posted where the work demands one, and communication and emergency arrangements, including how to raise the alarm and who responds, are agreed before work starts, not improvised afterward.

Every permit is time limited and specific to the conditions described, so if the weather changes, the isolation is disturbed, the space atmosphere shifts, or the shift changes and a new person takes over, the work stops and the permit is reviewed or reissued rather than simply continued on the strength of the original signature. When the job finishes, the permit is formally closed out, isolations are removed only once confirmed safe to do so, and the area is left in a safe condition for normal operation to resume.

As a core part of the ship's safety management system required under the ISM Code, the permit to work system exists precisely because so many serious shipboard accidents trace back to a hazardous job that was started informally, without the checks the permit forces, so treating it as paperwork rather than as the actual safety barrier it is has been the direct cause of real deaths on real ships.