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One lock, one key. Always.

You may have interpreted through organization surveys or transformational change exercises on the subject of safety, that the organization tends to put production over safety. Simply search for testimonies of organizations that may have demonstrated these types of actions and you conclude there is not just one industry that has singularly embodied this opinion. Each industry seems to surface this opinion as a lagging indicator of unfavorable safety performance.

I am a big believer that safety performance changes from the top down, and the leadership style of the likes of Paul O’Neill (former CEO of Alcoa) is an example of how organizations become successful by starting with a foundation on safety. I also believe that Paul O’Neill has it right in that a single change can become a catalyst for a safety transformation. There is one example of a catalyst that you can use to embed this transformation, but you may face an uproar like no other. Let’s see if you are up for it.

Every year, numerous Alcoa workers are injured so badly that they miss a day of work,” O’Neill continued. “I intend to make Alcoa the safest company in America. I intend to go for zero injuries. - Paul O’Neil, former CEO of Alcoa

Favorite conversations

I love talking to people in all types of manufacturing regarding their safety programs. I love to engage in these types of conversations because I always leave richer with new solutions or strategies to accompany a moral obligation to never become content regarding safety. I tend to allow our conversation to explore OSHA’s Control of Hazardous Energy regulation (1910.147), with one question. “For personal and or department energy control, when you utilize safety locks, is it one lock and one key, or do you have one key that goes to multiple safety locks?”

On the surface, this question might look innocent, but individuals tend to become passionate about their answers. You too might have just sat a little higher in your seat. I tend to find that individuals use safety locks in lockout strategies in one of three ways:

  • Keyed Different - Each individual’s lock has a single key to unlock. Each department’s lock has a single key to unlock it.

  • Keyed Alike - Each individual has a single key that unlocks multiple personal locks. Department locks have one key that unlocks multiple locks intended for group lockouts.

  • Hybrid - A hybrid of Keyed Different and Keyed Alike for personal or groups lockouts.

*it is understood that an individual could have several locks, all of which have a single key for each lock

When the type of locking strategy is discussed for energy control, I am passionately in the camp of all safety locks are to be keyed differently. Because of this passion, I tend to explore the reasoning when someone indicates that they manage differently. What happens when you lose the key? Or what happens when you lose one lock in a group of twenty needed to complete a lockout?

What I usually hear is a hidden cost that is justified by perceived efficiency gain. If you lose a single key intended for a group of locks, you typically have to replace the group of locks or take time to make a new key. Sometimes, you may even hear that a second key magically exists in someone’s office drawer. From the lock’s perspective, if you lose/damage one lock in a group that requires a specific quantity, you will most likely require this lock to be special ordered. Regardless if the key or the lock fails, you have a clerical burden to keep the energy control program in control. There are even markets that provide service in anticipation of you losing the key or damaging an individual lock and demand that it is replaced in kind.

I like then ask, what is the advantage of having a single key go to multiple locks? The argument always stresses that obviously, it is faster to place all the locks on and take all the locks off with one key serving multiple locks.

Wait!? Didn’t you say earlier that you don’t want to have an organization that views production over safety? But… uh.

Perceived value

This single value of framing speed is the reason why I have remained to favor one lock and one key for personal and departmental safety locks. I struggle with weighing the value of speed over the value of accuracy. The approach of a single key matched to a single lock emphasizes the importance of planning a lockout is just as important as planning the steps of a job.

Too often I have seen departments attempt to justify the ease of having one key serving multiple locks, and I have always loved the argument. If you are wanting to transform into a "one lock and one key" organization and get rid of all applications of keyed alike, here are some of your bullet points.

  • Less inventory. If you have one lock and one key, you only need one type of spare.

  • If you have multiple examples of keyed alike, you will require multiple spares of unique units of measure (e.g. box of 20 locks keyed alike)

  • If you have one key serving twenty locks to perform a lockout, and you see one key in a group lock box, how do you know all twenty locks got placed?

  • You can neatly hang all of the keys in a shadow box showing what is individually locked out. 5S program

  • Get a key ring indicating the label of the lock. Whereas, if the key is lost or the lock is damaged, you place the label on a new lock

  • Keyed alike locks can lead to errors when used with partial lockouts

  • One lock with one key for group lockouts forces more effective planning processes when locking out

  • One lock with one key for group lockouts forces more effective planning processes when unlocking

These types of bullets tend to get people to realize that they could be leading with hypocritical strategies when explaining the logic of having keyed alike scenarios. They could be interpreting OSHA’s Control of Hazardous Energy regulation (1910.147) primarily for speed of the energy control versus the intent of the energy control. I remain in the camp where all safety locks have a single key.


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