When One Lock Isn't Enough: Lockout Tagout for Teams
Most lockout tagout training starts with the same picture: one worker, one machine, one lock. It’s a good place to start. It’s also not what a real maintenance day looks like.
A planned outage can put mechanics, electricians, and a contractor crew on the same line at once. A repair that starts on day shift gets finished by nights. Someone needs a machine powered back up for a few minutes to check alignment. The lock owner leaves for the weekend with their key in their pocket. Each of those moments is a hand-off, and every hand-off is a place where energy control can quietly slip.
OSHA’s hazardous energy standard, 29 CFR 1910.147, has specific requirements for these situations. Here’s what they say, and what they look like on the floor.
1. Group Lockout: Every Worker Still Gets Their Own Lock
The core rule of lockout doesn’t go away when the crew gets bigger: each person exposed to the hazard is protected by a lock they control. Group lockout is how that rule scales to a job with ten isolation points and eight workers.
Under 1910.147(f)(3), a group lockout must give each authorized employee a level of protection equal to a personal lockout. In practice, that means:
One person is accountable. A primary authorized employee takes responsibility for the group working under the protection of the group lock, and confirms the exposure status of each person.
Each worker locks on. Every authorized employee attaches their own personal lock to the group lockout device, usually a lockbox holding the keys to the isolation locks, when they begin work, and removes it only when they’re done.
Multiple crews are coordinated. When more than one crew, craft, or department is involved, one authorized employee is assigned to coordinate the overall job.
Where it goes wrong: the “I’m just helping for a minute” worker who never locks onto the box, or a crew that treats the lead’s lock as covering everyone. A simple floor rule fixes both: if any part of your body goes into the hazard zone, your lock is on the box. No exceptions for short jobs.
2. Shift Changes: Never Leave a Gap
When a job outlasts a shift, the risk isn’t the work itself. It’s the minutes between one person’s lock coming off and the next person’s going on. If the equipment sits isolated with nobody’s personal lock on it, it isn’t really locked out. It’s just off.
Section 1910.147(f)(4) requires specific procedures for shift and personnel changes, including an orderly transfer of lockout or tagout protection between the off-going and oncoming employees. A good handover looks like this:
Lock on before lock off. The oncoming worker applies their lock before the off-going worker removes theirs. Protection overlaps; it never pauses.
Talk face to face. A note on a whiteboard isn’t a handover. The two workers walk through which points are isolated, what’s been verified, and the state of any stored energy.
Write it down. A short handover log, with isolation points, verification status, and names, gives the next shift something better than memory to work from.
Re-check before reaching in. The oncoming worker confirms isolation for themselves. They inherited the job, not the certainty.
3. Outside Contractors: Agree on the Rules Before Anyone Shows Up
Contractors bring their own people, their own locks, and often their own lockout program. That’s fine, as long as everyone knows whose rules apply. Under 1910.147(f)(2), the host employer and the outside employer must inform each other of their respective energy control procedures, and the host must make sure its own employees understand and follow the restrictions of the contractor’s program.
Questions to settle at the pre-job meeting, not on the floor:
Whose procedure governs each piece of equipment, and who signs off on isolation?
How are contractor locks identified, so your people can tell them apart from your own?
How do the two groups share a lockout when both are working on the same system?
Who has to be told before anything is re-energized?
Your own employees need one clear message too: a contractor’s lock is just as untouchable as your own.
4. When the Lock Owner Has Gone Home
It’s Friday night, the job is finished, and a lock is still hanging on a disconnect. Its owner left two hours ago. Cutting it off may feel like common sense, but without a defined process it’s a citation and a real hazard. That lock may be there for a reason nobody else knows about.
OSHA allows removal by someone other than the employee who applied the lock only under the direction of the employer, using a specific written procedure and training. Under 1910.147(e)(3), that procedure must at least include:
Verifying that the authorized employee who applied the device is not at the facility.
Making all reasonable efforts to contact that employee to let them know their lock has been removed.
Making sure the employee knows about the removal before they resume work at the facility.
Spell out who can authorize the removal, how the equipment is checked before the lock comes off, and how it’s documented. When that procedure exists before you need it, nobody is making it up at 11 p.m.
5. Testing and Positioning: The “Just for a Second” Re-Energize
Sometimes a machine has to be powered up mid-job to test a repair or jog a component into place. That brief window is exactly when people get hurt, because everyone’s focus is on the fix, not the energy.
Section 1910.147(f)(1) lays out the sequence for temporarily removing lockout devices to test or position equipment:
Clear the machine of tools and materials.
Remove employees from the machine area.
Remove the lockout or tagout devices following the standard’s removal requirements.
Energize and complete the testing or positioning.
De-energize and reapply energy control measures before work continues.
If your written procedure doesn’t cover this step, crews will invent their own version under time pressure.
6. Electrical Work: Simple vs. Complex Lockout
For electrical work, NFPA 70E adds a useful distinction. A simple lockout tagout involves a qualified person de-energizing equipment for their own work. A complex lockout tagout applies when the job involves things like multiple energy sources, multiple crews or crafts, multiple locations, multiple employers, or unusual disconnecting means or sequences. Complex jobs call for a written plan and a qualified person placed in charge of the whole lockout.
If your outage involves several of the situations above at once, assume it’s complex and plan it that way from the start.
A Quick Self-Check for Your Program
Can you answer “yes” to each of these?
Our written program covers group lockout, including who acts as the primary authorized employee.
Shift changes use a lock-on-before-lock-off handover, not a verbal “it’s locked.”
We exchange lockout procedures with every contractor before work begins.
We have a written, trained procedure for removing a lock when its owner isn’t on site.
Our procedures include the testing and positioning sequence.
Our authorized employees have practiced these scenarios, not just read about them.
If any of those gave you pause, that’s where to start.
Frequently Asked Questions
Does each worker need their own lock during group lockout?
Yes. Under OSHA 1910.147(f)(3), each authorized employee affixes a personal lockout device to the group lockout device, such as a lockbox, when they start work and removes it when they finish. Group lockout extends personal protection to a crew. It doesn’t replace it.
Can a supervisor remove another employee’s lock?
Only under the employer’s direction, following a specific written procedure that employees have been trained on. At minimum, it must verify the employee isn’t at the facility, make reasonable efforts to contact them, and make sure they know about the removal before they return to work.
Do contractors have to follow our lockout program?
OSHA requires the host and the outside employer to inform each other of their energy control procedures, and the host’s employees must understand and follow the contractor’s restrictions. Which program governs a given task should be agreed on in writing before work starts.
How should lockout be handled at shift change?
OSHA 1910.147(f)(4) requires procedures that ensure continuous protection during shift or personnel changes, including an orderly transfer of devices between off-going and oncoming employees. The safest practice is for the oncoming worker to apply their lock before the off-going worker removes theirs.
Get Help Building Lockout Procedures for Real-World Jobs
Herzig Engineering helps facilities write lockout procedures that account for crews, shift changes, contractors, and the jobs that don’t fit the one-worker, one-lock picture, and trains the people who carry them out.
Learn more at herzigengineering.com/services/lockout-tagout-programs or contact our team: 816.734.8300 · Hello@HerzigEngineering.com
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