People forget things. Often, they'll even forget vital things. It happens especially when they're distracted, busy, or in a rush. It's normal, but when it's combined with powered equipment, it's also highly dangerous.
That's why implementing and following a carefully planned lockout/tagout (LOTO) procedure is so important.
Case Study: A LOTO Procedure Gone Wrong
Lockout/tagout procedures can sometimes seem burdensome, and it can be tempting for workers and supervisors to skip a step or set aside the checklist. But following the process to the letter is critical.
To see why, consider this case study:
Employees were performing repairs on an 8-ft-diameter pipeline that carried hot oil. They had properly locked and tagged pumping stations, pipeline valves and the control room prior to beginning repairs. When the work was completed and inspected all lockout/tagout safeguards were removed and all elements were returned to their operating state. At this point, control-room personnel were alerted that the work was completed, and they were requested to start up the system five hours earlier than was scheduled.
Two supervisors not aware of the early start-up decided to inspect the repairs themselves. They were required to walk inside the pipe with lights in order to perform the inspection. They did not perform any lockout/tagout procedures for the inspection process. They also neglected to notify control-room personnel of their last-minute decision to inspect. As the control-room operators started the system as instructed, oil began to flow through the pipe killing the two supervisors.
In this scenario, it could be argued that the lockout/tagout procedures were conducted properly up to and including the conclusion of the repair job. The two supervisors who tragically lost their lives performed their inspection after the repairs had been completed. However, they were also performing their inspection within the originally posted repair window (remember, the job was wrapped up five hours early). In fact, the supervisors likely believed that the pipelines were still in a state of repair and would be for a few more hours.
There is, unfortunately, a lack of foresight hardwired in human thinking. It is very difficult for people to stop and say to themselves something like, “Hey, wait a minute, we finished the job early, so let’s put up warning signs in case someone performs an unplanned inspection.” We're just not built to think like that. Proactive actions like this must be drilled in us through repetition, regulation, and checklists, which is why procedures like lockout/tagout exist in the first place.
How Lockout/Tagout Works
Lockout/tagout ensures that a machine or tool of any sort is made impossible to use when its authorized operator is not around. This is especially important for:
- Machinery that uses some form of energy, such as electricity, fuel, or compressed air
- Tools or materials that pose an injury hazard, like cutting or falling
- Any device like a control panel or tool cabinet that gives access to other dangerous equipment or dangerous situations like explosions or asphyxiation
Basically, the rule applies to any piece of equipment that has the potential to cause injury or death if it's left in a state where it could be used by an unauthorized individual or where it could re-engage by itself.
Like the name implies, locking out a machine means applying a device to it that keeps it in an inoperable state.
Once the equipment is locked out, it also needs to be tagged out. Tagging out means attaching a tag that displays a warning about unlocking the device without authorization.
Only one person should be authorized to unlock or reconnect a piece of equipment that has been locked out, and that's the person who locked or disconnected it after it was last used.
Your Lockout/Tagout Checklist
Those basic LOTO steps were followed in the case study outlined above. The lesson here is that lockout procedures also need decision tree questions built into the steps.
To ensure a correct and safe LOTO procedure, you should follow these seven steps:
- Prepare a clear, detailed, and unambiguous written procedure for closing down and restarting the equipment
- Notify employees that a shutdown or start-up procedure is happening, and again when the procedure has been completed
- Perform the shutdown and start-up exactly according to the written procedure
- Disconnect all primary energy sources, such as shutting off electricity or gas and disconnecting conduits (like power cords), properly and in the correct order
- Secure secondary sources of energy, such as residual gas, spring tension, or even applying parking brakes to a vehicle
- Verify and seal – after shutting down, test the equipment to confirm that it is indeed off and in a safe, inoperable state, then apply the lock and tag
- Communicate the LOTO status to the team as well as to incoming shifts
As you can see, there are opportunities to respond to changes of scope or timeline at steps 1, 2, 3, and 7.
A yes/no or if/then line item could be included at these steps. It could read: “if the LOTO status changes earlier than planned, follow these additional steps.” The additional steps must include sending clear announcements to all relevant parties that the machine will be back online earlier than originally planned and require clear confirmation that this message has been received.
A Proper LOTO Procedure Is a Proactive Step
It's easy to think of these types of solutions in hindsight. But as every project manager and engineer knows, yesterday’s hindsight becomes tomorrow’s foresight. Proactive, checklist-based activities such as LOTO will help you save more lives on the job.