Documented authorisation system controlling specific high-risk tasks (hot work, enclosed-space entry, electrical isolation, working aloft).
In practice
Issued by the chief officer or chief engineer for any non-routine work — hot work, enclosed space entry, work aloft. Validity typically 4-12 hours; signed off after work completion. PSC inspectors sample current and recent permits.
Regulatory detail & full definition
A permit-to-work (PTW) is a formal, documented authorisation system that controls specific high-risk shipboard tasks such as hot work, enclosed-space entry, electrical isolation and working aloft or overside. Required under ISM Code Element 6, each permit identifies the task, its hazards and controls, the persons authorised, the validity period and the post-work close-out. A permit cannot be self-issued: a separate authoriser - typically the Master, Chief Engineer or Chief Officer - must sign it off, and the PTW is normally used together with a Job Safety Analysis (JSA) as the standard pre-task workflow.