Work around rotating machinery — Part 2
In Part 1, we looked at some of the hazards that arise when working near rotating machinery and how to protect yourself. In Part 2, we look at five other such dangers.
Being crushed, cut or maimed by a ram, blade or auger
Just because rotating equipment is electrically de-energized does not make it safe. You could be working under a hydraulic cylinder that still has potential energy because it is in the wrong position and the safety clamps are not engaged. If sharp edges, such as the blades and “teeth” of the grinder, cannot be blocked with a sheet of plywood, at least cover them with a tarp or other thick material.
Injuries from contact with the auger often occur due to falling into a feed chute. The most obvious solution is to walk around, not over, the chute. If this is not possible or if work must be done above the chute, cover the chute with a material sufficient to support your weight, such as a sheet of plywood. But make sure it’s in place.
Such barriers also prevent tools, parts, or other objects from being dropped into the auger and, thus, eliminate yet another safety hazard that can occur once the start button is pressed.
Rotating machinery often heats up; you can burn yourself on contact with a motor under heavy load. Sometimes it’s not the machines that present the burn hazard, but the material inside. Hot processes, such as extrusion, can present a significant burn hazard.
One solution is to wear long sleeves. But this presents the risk of being drawn into the machine if it is not locked all the time you are there. If people have to work near dangerous heat sources, insulating materials must be permanently installed to protect them. It may also be possible to temporarily cover hot surfaces with an insulating blanket.
In some cases, the machine will need to be artificially cooled until the tactile contact or ambient temperature targets are met. For example, to repair the feed system of an annealing furnace, you may need to lower the temperature of the furnace by forced air cooling for several hours.
To be dragged in a machine
Long sleeves that can protect you from a burn or electric shock can also catch on rotating equipment and cost you your arm. In many types of facilities, such as a power plant, the typical maintenance technician encounters all three hazards several times a day.
So you see electricians still wearing long-sleeved shirts with non-metallic cufflinks. With a tight cuff, there is little danger of being pulled into a machine. But as an added precaution, electricians may choose to roll up their sleeves before putting their hands near rotating parts of equipment. Obviously, a collar is out of the question.
During the COVID-19 shutdown in 2020, hair salons and barbershops were closed or people stayed away for fear of illness. Two menswear trends have emerged: one is a super short DIY haircut; the other is much longer hair.
Most guys who chose the second option eventually found the need to tie their hair back to keep it out of their eyes. If the ponytail is behind you and the machine is in front of you, is there a potential danger? Maybe not – if you always back away from a machine without turning your head and never turn your head when someone talks to you. Chances are, you’re not that person.
Having that ponytail in the back is like wearing a tie in the front. Enter it. Your shirt collar should hold it in place. One way to avoid choking around rotating equipment is to prohibit the wearing of ties around such equipment. You might want to consider this same strategy for managing your ponytail. In other words, snip-snip.
Getting hit by projectiles due to loss of structural integrity of the machine
Things break. In some cases, they fail spectacularly. At a coal-fired power plant, the windings of a generator broke while it was at operating speed. Damage to this end of the turbine deck was extensive. All damage was due to flying parts.
The most effective safety solution to this risk is to install vibration monitoring on all rotating equipment that may present a projectile hazard. Inexpensive wireless sensors make this very easy to do. With a PLC or other control system, the machine can be automatically stopped when the vibrations cross a predetermined threshold.
What can you do to protect yourself whether the sensors are there or not? Know where the two nearest exits are, wherever you are. That way you can run for one when you hear that last half minute of rumble before the bang. If you don’t have time to get to an exit from where you are, find something sturdy that you can use as a blanket.
Getting hit by work pieces that “have left their chuck”
Part of your lockout/tagout should include ensuring that no work in progress is left in the machine unless there is no convenient way to remove it.
Closely related to this is a method for finding lost tools. Check your tools before turning the power back on. A tool count is considered the most reliable way, but if you have an organized tool pouch, backpack, cart, etc., each tool will have its specific place. Check each location as well as the work area.
There seem to be a number of things to remember for being around rotating equipment. You can boil it down to three key actions on your part: thinking and planning carefully before doing the job, being careful while working, and cleaning up after the job.