Each year in the United States about 50 people are killed in crane accidents and hundreds more are injured. These incidents are frequently attributed to poorly inspected rigging equipment and improper or unsafe rigging techniques performed by inadequately trained riggers.
During the development of our own Wire Rope Safety training videos, we were fortunate to receive some expert feedback from Howard Kaplan, trainer and owner of Liberty Crane & Rigging Consultants in Phoenix, Arizona. We recently caught up with Howard again for a brief Q&A about wire ropes, rigging safety, and the importance of proper training.
I started my career way, way back in 1982 at a trade school, and the best part about that trade school was I had some instructors who just loved heavy equipment and they were great instructors simply because they had a passion for teaching. I was very, very lucky that I didn’t learn a lot of bad habits. I learned the right way to operate stuff right from the beginning. And since my instructors really liked teaching, it gave me a kind of sense for it as well. At the trade school you became a sort of mentor as you became more experienced. So as you progressed through the program it was your job to teach the newer people as they came on. I didn’t even know you were supposed to be nervous doing public speaking. I didn’t know any of that. I was just being a heavy equipment operator and helping other people out because they helped me out.
After that I went into construction for several years. I joined the military. I was in the military for almost 14 years. I was in the crane rigging field my last 7 years in the Navy. When I got out I went to work for a crane company. I’d been a crane operator in the Navy, and they’d sent me to all these schools to be a crane instructor.
Well, in 2010 OSHA came out and said every mobile crane operator needs to be certified. Truth be told, probably 70-80% of crane operators out there already were, but what happened was the little mom-and-pop shops, the folks with one or two cranes, find out that their crane operators need to be certified and they start freaking out. Most of those guys unfortunately are not crane operators. If you met one on the street he would tell you he was an electrician, he’s a plumber, he’s a welder, he is anything but a crane operator. But the mom-and-pop has a crane that they need to use incidentally, to pick stuff up and put it down, and they can’t for the life of them understand why somebody would need to be certified to run that thing when they barely even use it. And truth be told, those are the ones that need the certification and training far more than somebody who does it every single day. Those are the types of customers I’ve had the last couple of years.
Way back in 1970 the department of labor came out with the OSHA act that said everybody has to be trained to recognize the hazards associated with their particular field. The issue was, back then, they knew that there were going to be a lot of new tasks coming up, a lot of new jobs coming up, and people had to be trained on how to do all that. So, if you were just trained on how to be a rigger, being trained means you’re qualified.
There is a new requirement that stipulates that riggers do need to be qualified, and they spelled it out a little clearer in the crane standard, but the problem is, you take a guy who’s working underneath the hook of a crane with a sling — that guy needs to be qualified and they spell it out in a couple of different laws. You take that same guy, and now he’s working underneath an excavator or backhoe. Same sling, still picking up a load, but now it’s on an excavator. Now it’s not so clearly spelled out how that he has to be qualified. He does – it is written in the law, but it’s just not as clear and not as easy to find. So, people just say, “well, it’s only a backhoe, how bad can it be?”
The problem is if you grab hold of a sling — take a wire rope sling, for instance — and you throw it on a hook, and you motion your finger up and the crane operator picks up the load… If the load comes off the ground and the sling didn’t break… everybody’s happy. No harm, no foul. But, if you didn’t know what the capacity of that sling was; if you didn’t know the capacity of the hook, or what the load weighed… if you didn’t know all those things and you were successful, you were only successful because there’s a design factor built into that sling that prevents it from just failing immediately. But failures do still happen. Slings break all the time – people overload them, they misuse them, they don’t know what it is they’re doing.
Generally speaking it’s in the hitching – how they actually connect it to the load. There are often capacity reductions, and/or additional stresses put on the sling that a layman wouldn’t see. Let’s say you take a two-leg sling – what we call a two-legged bridle – and you put it on a hook. You were going to pick up a piece of steel culvert and you were going to pick it up from both ends, with really big hooks on either end. You have to factor in the length of the sling, and the length of the culvert. Let’s just say, for sake of analogy, that both ends of the sling just barely fit – the hooks just barely fit into the ends of the piece of culvert, so that the wire rope sling is very very close to the culvert all the way across the top, and when you pick it up, it’s a triangle, but it’s a very, very small triangle, and the hook itself is maybe a couple feet off the top of the culvert. That triangle is called a sling angle, and the closer that sling angle is to horizontal, the more stress is being introduced into the sling. That culvert weighs 1000 pounds. And you and I think that two 500 pound slings is going to do the job, because, hey, that’s half the load times two. But what happens is, at 30 degrees, that sling angle actually creates 1000 pounds of stress on each sling. And it’s not anything that you can see – you just need to be trained to know the stress that that angle introduces to the sling.
So what happens is, a guy grabs a sling that’s cleared for 500 pounds, he rigs it that way, makes the lift, and nothing happens. Well, nothing happens because there’s a design factor, a safety factor, built into that sling. And this guy keeps doing it, and doing it, and doing it, and every single time he’s done this he’s overloaded that sling. It’s like taking a paper clip and bending it back-and-forth – if you keep bending a paper clip back-and-forth enough, eventually it’s going to break. Certainly that sling is going to do the same thing. And then when that happens, and OSHA comes out, the very first thing that the rigger says is “I didn’t overload the sling, it was rated for 500 pounds and the load was only 1000 pounds and I had two slings.” And truth be told, he overloaded it a bunch of times, he just didn’t know it.
Generally, I have an 8 hour basic rigging safety program that introduces riggers to sling angle, to sling stresses and how they affect lifting. And I do training from that 8 hour course up to a 40 hour course which is an advanced rigging program. But there’s two problems with that. First, you can’t teach experience. And the other thing with sling angles is that you’re right, it’s physics, it’s geometry, and it’s trigonometry, because it’s the study of angles. You can’t be a dummy. I get guys that get really upset all the time at me when I start out our rigging class by handing out calculators. And they’re like “wait a minute, we thought this was a rigging class.” They want to know why they have to do math and my favorite answer is: “well, because you want to try and defy gravity and gravity is a known force. To calculate that force you need a calculator.”
The biggest problem with rigging is that you learn how to move the levers, and you manipulate the crane, and usually nothing bad happens. Why wouldn’t you think everything is ok? Truth is, you could have been within pounds of a catastrophic failure, but there is no way to physically see that. And it’s not until something does happen that people understand it could have happened years ago.
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