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.

Last verified 15 days ago