Group Lockout, Shift Changes, and Lock Removal

A basic lockout with one worker and one disconnect is easy to follow. Real maintenance is often messier: a whole crew on one machine, a job that runs past the end of a shift, a contractor who brings their own locks, a worker who goes home with a key, or a technician who needs power back on for a moment. Those are the times when people get hurt. OSHA's standard, 29 CFR 1910.147, has specific rules for each of these cases. This is the depth an authorized employee or a lockout coordinator needs.

What You Will Be Able to Do

• Run a group lockout so that every worker has their own protection.
• Hand a lockout from one shift to the next with no gap.
• Coordinate lockout with outside contractors.
• Follow the legal procedure when a worker's lock is left behind.
• Test or position a machine during a lockout.
• Decide whether the minor servicing exception actually applies.
• Explain the periodic inspection, and what the employer's energy control program must include.

The Energy Control Program

Everything here sits inside your employer's energy control program, which has three required parts:

1. Written procedures for each machine, covering the purpose, the steps to shut down, isolate, block and secure, the steps to place and remove locks, and how to test for effectiveness.
2. Training for authorized, affected and other employees. Retraining is needed when the job changes, machines or processes change, a new hazard appears, procedures change, or an inspection shows gaps.
3. Periodic inspections at least once a year.

The written procedure can be skipped only when a narrow exception applies. All of these must be true: the machine has no stored or residual energy that could harm workers, it has one energy source that can be easily identified and isolated, locking that source fully shuts it down, one lock achieves that, the lock stays under the control of the worker, servicing does not create a hazard to others, and there have been no past accidents from unexpected startup.

Machines installed or rebuilt since January 2, 1990 must have isolating devices designed to accept a lock.

Group Lockout

A group lockout is required when more than one person works on the same machine. The rule is that each worker gets the same protection they would have with their own lock.

Group Lockout Hardware

• Hasp: a scissor-shaped clamp with several holes. It goes through the isolating device, and each worker puts their lock in a hole. The device cannot be turned on until the last lock comes off.
• Group lockbox: used when there are many isolation points. An assigned worker locks each point, puts the keys inside the box, and every worker then adds their own lock to the box. Nobody can reach the keys until everyone has taken their lock off.

How to Run It

1. Name one authorized employee as the primary for the job. The primary is responsible for the group.
2. The primary carries out the lockout, including isolating, locking, releasing stored energy and verifying.
3. Each worker adds a personal lock to the hasp or box before they start.
4. Each worker should verify that the machine is isolated, or watch the primary do it. You have the right to see for yourself.
5. Everyone keeps their own key.
6. Each worker removes only their own lock when finished with their part.
7. The primary removes the last locks after everyone is off, the area is clear and the machine is inspected.

Why must each worker apply their own lock? A lock protects the person who holds the key. Each worker is responsible for their own safety while exposed to the hazard. A single supervisor's lock protects no one if the supervisor forgets a worker is still inside. It is one point of failure with someone else's life on it.

Warning: Never let someone else lock on for you, and never lend your lock or key. If your name is on the lock, you must be the one who put it there and the one who takes it off.

Worked example: Four mechanics overhaul a press with three energy sources.

1. The lead mechanic, as primary, shuts the press down, locks the electrical disconnect, the hydraulic valve and the air valve, bleeds both lines and pins the ram.
2. The lead puts the three keys in a group lockbox and adds a lock to it.
3. The other three mechanics add their locks to the box after checking the isolation.
4. Mechanic 2 finishes first and removes his lock. The box stays locked by the others.
5. When the last mechanic is off, the lead inspects, clears the area, opens the box, removes the locks and tells the operators.

Shift Changes

If a job runs across shifts, the machine must never be left unprotected, even for a moment.

1. Incoming workers meet outgoing workers at the machine.
2. The outgoing crew explains the job status and any hazards.
3. Incoming workers apply their locks first.
4. Then outgoing workers remove theirs.
5. Incoming workers verify the isolation.

If the outgoing worker removes a lock first, the machine has a gap with no protection. Procedures may also use a coordinator's lock to hold the isolation during the handoff, as long as protection stays continuous.

Outside Contractors

When contractors service equipment at your site, each employer must know the other's procedures.

1. The host employer and contractor exchange lockout procedures before work starts.
2. The host tells the contractor about machine-specific hazards.
3. Each side makes sure its workers understand and follow the other's restrictions.
4. Both agree how to handle group lockouts, shift changes and removal of locks.

Contractors keep their own locks on. If the two lock systems differ, a shared hasp keeps both protected. The host must not start anything until the contractor confirms that its people are clear.

When a Lock Is Left Behind

Only the person who applied a lock removes it. There is one exception, for when that worker is not available. It must be spelled out in the written program, and it must give the same level of safety as the worker removing it. OSHA requires at least these steps:

1. Verify that the worker who applied the lock is not at the facility.
2. Make all reasonable efforts to reach the worker and tell them their lock will be removed.
3. Remove the lock under the direction of the employer's designated person, following the program.
4. Make sure the worker knows that the lock was removed before they start work again at the facility.

In practice, sites add steps: check the machine, confirm with a supervisor, inspect the area as if starting a return to service, record the event, and review why it happened. A bolt cutter is never the first move. If someone keeps leaving locks on, that is a training issue.

Testing and Positioning

Sometimes you need power back for a moment, such as to test a repair or move a part into position. OSHA's rule allows this only by this sequence:

1. Clear the machine of tools and materials.
2. Remove workers from the area.
3. Remove the locks, following the release procedure.
4. Energize, and run the test or position the part.
5. De-energize, and reapply all energy control measures before you continue.

There is no such thing as "half locked out." Once you start the test, nobody is protected by lockout until it is reapplied and verified.

Minor Servicing

Minor tool changes and adjustments that happen during normal production are not covered by the standard if they are routine, repetitive and integral to using the machine, and if the employer uses other measures that give effective protection. Examples may include a quick die adjustment using a guarded tool, or using a special tool to clear a jam from outside the guard.

Run through this check before you rely on it:

Being fast is not enough to qualify. Reaching into a press because it is quicker does not meet this test.

Cord-and-plug equipment is also excluded when the machine is unplugged and the plug stays under the control of the worker doing the service. Keep the plug in sight, or use a plug lockout.

Special Situations

• Capacitors and batteries. On drives, solar and battery systems, energy can remain long after the disconnect is open. Follow the maker's discharge procedure and wait time, then verify with a rated meter.
• Machines with two or more isolating points on different levels. Walk the whole path, because a label on a panel may be out of date.
• Piping. Closing one valve may not be enough for hazardous fluids. Your procedure may call for double block and bleed, or blinding the line.
• Mobile equipment. Remove keys, set brakes, chock wheels and block raised attachments.

The Periodic Inspection

At least once a year, each energy control procedure must be inspected. This is not a paperwork exercise. The inspection must:

• Be done by an authorized employee who is not using the procedure being inspected.
• Check that the procedure is being followed and that it is adequate.
• Include a review of each authorized employee's responsibilities. For tagout, it also includes affected employees.
• Be certified with the machine, the date, the workers included, and the inspector's name.

Common findings include procedures that no longer match the machine after changes, missing isolation points, and workers who cannot describe the steps. Each gap must be fixed.

Common Mistakes

Check Your Understanding

1. A maintenance lead tells the crew, "I've got my lock on, so we're all covered." Is that acceptable?

No. Each exposed worker needs their own lock on the group hasp or lockbox.

2. A job runs into the night shift. The day crew is ready to leave and the night crew is late. What should happen?

The day crew stays locked on until the night crew arrives and locks on first, or the employer's coordinator procedure keeps the isolation continuous. The machine cannot be left with no protection.

3. On Monday morning, a machine still has a lock from a worker who is on vacation. What are the required steps?

Confirm that he is not on site, make all reasonable efforts to reach him, remove the lock under the employer's specific procedure, and make sure he is told before he resumes work at the facility.

4. A technician needs to jog a machine to line up a coupling, then keep working. What is the sequence?

Clear tools and people, remove locks, energize and jog, de-energize, reapply all locks and verify. Then go back to work.

5. An operator clears a jam from a wrapper about 20 times a shift using a tool made for it, without reaching past the guard. Does that require lockout?

It may fall within the minor servicing exception, if it is routine, repetitive, part of production, and the method gives effective protection. If she must reach past the guard, lock it out.

Key Takeaways

• In a group lockout, each worker has a personal lock on the hasp or lockbox, and one primary is in charge.
• At a shift change, incoming locks go on before outgoing locks come off.
• Exchange lockout procedures with contractors before work starts.
• Removing someone else's lock needs a written procedure: verify they are gone, try to reach them, remove it and tell them before they return to work.
• For testing, follow the clear, remove, energize, then re-lock sequence.
• Minor servicing must be routine, repetitive, integral and effectively protected.
• Each energy control procedure is inspected at least once a year.