Key takeaways
  • A generic LOTO procedure is not usable at the machine. Each piece of equipment needs its own energy sources listed and its own isolation points identified.
  • Verification of zero energy is the most safety-critical step and the one most often skipped under time pressure.
  • Group lockout and shift handover are where multi-person jobs go wrong.
The step that is skipped first
Verifying zero energy, when the job is already late

Every other step leaves physical evidence: a lock is on or it is not. Verification leaves none, takes a minute, and feels redundant when you are confident. That combination is why it is skipped, and why it is the step worth designing around.

The sequence

  • Prepare. Identify every energy source for this machine: electrical, pneumatic, hydraulic, thermal, chemical, gravity and stored energy in springs or capacitors.
  • Notify. Tell everyone affected before anything stops, including the next shift if the work will cross a handover.
  • Shut down. Using the normal stopping procedure, not an emergency stop, unless the situation requires one.
  • Isolate. Operate each disconnect, valve or breaker identified in the preparation step.
  • Lock and tag. One lock per person, each with a tag naming the person and the date. Never a shared lock.
  • Release stored energy. Bleed pressure, block or lower suspended parts, discharge capacitors, allow thermal cool-down.
  • Verify. Attempt a normal start, confirm no movement, and test with an instrument where electrical isolation is involved. Return the control to off.

Why generic procedures fail at the machine

A site-level LOTO policy explains the principle. It cannot tell a technician that this particular press has a second pneumatic supply behind the guard, or that the accumulator holds pressure for four minutes after isolation. That detail belongs to the machine, and without it the procedure is advice rather than instruction.

The practical answer is a short machine-specific sheet per asset: energy sources, isolation point locations, verification method, and any sequence that matters. Photographs beat descriptions.

Group lockout and handover

Multi-person jobs fail in two predictable places. First, when one person applies a lock on behalf of others, which removes each individual's control over their own safety. A group lockbox with every worker's personal lock on it solves this. Second, at shift change, where the incoming crew must apply their own locks before the outgoing crew removes theirs, with an explicit handover rather than an assumption.

Removing a lock that is not yours

You will eventually face a lock whose owner has gone home. Have a written exception process before you need it: verified attempts to contact the owner, physical confirmation the machine is clear, sign-off by a named senior person, and a record. Deciding this in the moment is how people get hurt.

Making the procedure available where the work happens

A procedure in a binder in an office is not available at 2am at the machine. The machine-specific sheet needs to reach the technician where they are. Sending it as a step they complete, with the verification recorded and photographed, both puts it in their hand and produces evidence the isolation was performed, which is the record you want after an incident.