Lockout / tagout
Isolating energy sources before maintenance — locks, tags, verification.
Why it matters
Inadvertent re-energisation during maintenance kills and maims engineers regularly. Lockout / tagout is the discipline that prevents it.
Common hazards
- Electrical re-energisation by another department.
- Stored pressure (hydraulics, pneumatics, refrigerant).
- Gravity (raised loads, valves above closed pipework).
- Residual thermal energy (boilers, exhaust).
Practical checklist
- Identify every energy source feeding the equipment.
- Apply a physical lock and a personal tag for each isolation point.
- Test for zero energy at the point of work.
- Document the isolation log.
- Remove locks only in the reverse order, by the personal owner of each lock.
Mistakes to avoid
- Using a single 'departmental' lock instead of personal locks.
- Removing another person's lock without their consent.
- Skipping the zero-energy test.
Primary sources
- IMO MSC.1/Circ.1401 — Guidelines on safe access to tanker bows site unreachable
- OCIMF Marine Injury Reporting Guidelines · ocimf.org
High confidence
Last verified