3.1 The six steps of applying lockout

1 The six steps at a glance

1. 1
   (d)(1) Preparation for shutdown — know the type and magnitude of the energy, its hazards, and the means of control, before anything is switched off.
2. 2
   (d)(2) Machine shutdown — shut down using the established procedure for that machine, in an orderly way.
3. 3
   (d)(3) Machine isolation — locate and operate all the energy isolating devices needed to isolate the machine from its energy sources.
4. 4
   (d)(4) Device application — affix lockout or tagout devices to each isolating device, by the authorized employees.
5. 5
   (d)(5) Stored energy — relieve, disconnect, restrain or otherwise render safe all potentially hazardous stored or residual energy.
6. 6
   (d)(6) Verification of isolation — before starting work, verify that isolation and deenergization have actually been accomplished.

Around those six, two more actions come from elsewhere in the standard: the notification of affected employees before the controls are applied, required by 1910.147(c)(9), and the fact that only the authorized employees doing the work may apply the devices, required by (c)(8). Appendix A folds the notification in as step 1 of its sample sequence, which is where it belongs on a real procedure.

2 Step 1: preparation is a knowledge requirement

1910.147(d)(1) says that before an authorized or affected employee turns off a machine, the authorized employee "shall have knowledge of the type and magnitude of the energy, the hazards of the energy to be controlled, and the method or means to control the energy."

Three details are worth catching. This is the only step that happens entirely in someone's head and on paper — nothing is touched. It names the affected employee too, so the requirement holds even when an operator does the shutting down. And it is the paragraph that makes the written procedure operationally necessary: knowledge of type, magnitude, hazards and control methods for a machine you service twice a year does not live in memory, it lives in the document you are about to follow.

3 Steps 2 and 3: orderly shutdown, then isolation

1910.147(d)(2) requires the machine to be turned off or shut down using the procedures established for that machine, and adds a clause that matters more in process plants than in a machine shop: "An orderly shutdown must be utilized to avoid any additional or increased hazard(s) to employees as a result of the equipment stoppage."

Slamming a main disconnect open on a running line can create hazards of its own — product left in a heated zone, a partially formed part jammed in a die, a pump deadheaded against a closed valve, a conveyor dumping load at the transfer, an exotherm with no cooling. The normal stopping procedure exists for a reason and the standard asks you to use it. Appendix A step 3 puts it plainly: if the machine is operating, shut it down by the normal stopping procedure — depress stop button, open switch, close valve.

Then, and only then, 1910.147(d)(3): all energy isolating devices needed to control the energy shall be physically located and operated so as to isolate the machine from its energy sources. "Physically located" is the phrase that sends you to the isolation-point list from Part 2, Chapter 2. Operating a disconnect from a screen is not operating an energy isolating device.

4 Step 4: applying the devices

1910.147(d)(4)(i) requires lockout or tagout devices to be affixed to each energy isolating device by authorized employees. (d)(4)(ii) requires lockout devices to be affixed in a manner that will hold the isolating devices in a "safe" or "off" position — a lock hung on a handle that can still be moved has not met this.

Where tags are used instead, (d)(4)(iii) requires them to be affixed so as to clearly indicate that operating or moving the isolating device from the safe or off position is prohibited, and adds two placement rules. Under (d)(4)(iii)(A), where the isolating device is capable of being locked, the tag attachment shall be fastened at the same point at which the lock would have been attached. Under (d)(4)(iii)(B), where a tag cannot be affixed directly to the device, it shall be located as close as safely possible, in a position immediately obvious to anyone attempting to operate the device.

"Immediately obvious to anyone attempting to operate the device" is a good test to apply to your own locks and tags. Stand where the person who might energize this machine would stand, and look. If they would not see it, it is in the wrong place.

5 Steps 5 and 6, and why they are last

Part 2, Chapter 3 covered stored energy in detail; the thing to notice here is purely about sequence. 1910.147(d)(5)(i) starts with the words "Following the application of lockout or tagout devices" — the bleed comes after the lock, so that nothing can refill what you just emptied. And (d)(6) comes after the bleed, because a verification performed before the stored energy is relieved proves nothing about the state you will actually be working in.

1910.147(d)(6) itself is one sentence: "Prior to starting work on machines or equipment that have been locked out or tagged out, the authorized employee shall verify that isolation and deenergization of the machine or equipment have been accomplished." The next chapter is entirely about how that verification is done, because it is the step most often reduced to a glance at a handle.

6 The sequence as a card in your pocket

Most experienced crews carry a mental version of this list, and it is worth writing yours down in the standard's own order so that it survives a bad night. A compact form that maps one-to-one onto 1910.147(c)(9) and (d):

Eight tiles, seven of them before a tool comes out. That ratio is the point of the whole standard, and it is why a lockout on an unfamiliar machine takes twenty minutes and a lockout on a machine with a good written procedure takes five. The difference is not skill — it is whether somebody already did the walkdown for you.