What is Lockout Tagout (LOTO)?

The most dangerous moment in maintenance is not the work itself but unexpected start-up during it: someone else restoring power, a control system resuming automatically, or stored energy releasing suddenly. Lockout tagout exists to make that physically impossible rather than merely agreed verbally.

The energy most often forgotten is not electrical but residual: pressure trapped in a line, a suspended weight that can drop, a compressed spring, retained heat, or fluid that can flow in from another direction. This is why isolation does not end at opening a breaker — it ends at verifying that the energy is actually at zero.

That last step is the most frequently skipped and the most important. Verification is what turns isolation from an assumption into a proven fact.

On sites where maintenance is carried out by contractor crews, a recurring challenge appears: overlapping lock ownership. Equipment is isolated by one crew and worked on by another in a later shift, leaving responsibility for lock removal unclear at handover. This is why a record of who applied each lock and when, together with documented shift handover, is part of the procedure rather than administrative overhead on top of it.

• Permit to work
• Confined space
• how risk is assessed
• JSA

Isolated equipment remains an area nobody outside the authorised crew should approach for the full duration of the work. Defining the equipment perimeter as a zone during the maintenance window turns any unexpected entry into a case someone is alerted to at the time, and leaves a record of who entered and when. Read about the platform.