CMU School of Drama


Friday, April 19, 2019

The Life Expectancy of a Chain Hoist

What BLUMANO Thinks About: We once had a chat with a rental company – who owned several hundred electric chain hoists about an accident that happened to them. The owner of the company told us that during an installation, part of the chain hoist’s lifting mechanism, which was part of its upper suspension, broke down and the entire machine (with the load lifted) shattered to the ground.

Fortunately, no one was injured or killed, and the matter was settled civilly between lawyers and insurance companies.

4 comments:

Cooper Nickels said...

This is a really important issue that I feel like people do not talk about enough in our line of work. It not only applies to big things like chain hoists that seem to have obvious, big ramifications for when they fail, but also with other things we use like hardware. There are many types of hardware that are only meant to be used once or for a short period of time that we will use for multiple applications and for much longer than they should be. It is hard to inspect all of this all of the time, but it is still important, because a failing bolt could be just as catastrophic as a failing chain hoist. This is difficult because a large part of me always wants to reuse things as much as possible to have a more green process with everything, but sometimes that is just unreasonable and can even be unsafe.

Chase Trumbull said...

It seems to me that we are coming to a time when hoist manufacturers should start implementing a clock of sorts that measure the various factors that move a hoist towards the end of its lifespan. I imagine it working like a “lamp hours” clock in a projector, except there are obviously many more factors at play. That said, there are a couple of issues I can identify with this idea. First, because of the complex nature of the task, the device would probably be expensive to develop and produce. Second, I imagine that it could not provide a guarantee, since there are likely some factors that cannot be measured. Due to this potential for inaccuracy, manufacturers would be risking responsibility for errors or failures caused by elements they could not predict. I think it is much more likely that we will start seeing compliance laws around tracking hoist use.

Margaret Shumate said...

This is kind of terrifying. I’ve never seen any documentation regarding the actual usage and records of chain hoist/chain motor usage at any place I’ve worked. I would imagine that that is partially because I haven’t been more than loosely involved in rigging for those organizations, but even so, I’ve never even heard the matter of life expectancy discussed. I’m nearly certain that non of those organizations were keeping records of use, which makes me think that they likely were not considering life expectancy at all. Chain hoists in our industry are usually viewed as long term investments to buy and forget about. They are treated as trustworthy as long as you obey the load limits. I’m surprised there haven’t been more high profile incidents, considering how abused these pieces of equipment are. The stakes when rigging such large heavy objects so quickly so often are staggering. It seems like only a matter of time before something goes wrong, especially when things like life expectancy aren’t even considered.

Mattox S. Reed said...

This is a big an scary issue that I think we see all the time in our industry. Thankfully when it comes to think like rigging hardware and overhead equipment most people are vigilant and carefully in what they choose to put over peoples heads and they look into this. That being said chain hoists not being made for our industry and the ways in which we use them worry me in our ability to judge the life span of a motor. I agree totally with what chase said about some sort of life time clock on the device these are not a device in which i would want even the slightest doubt in its abilities. And while this is definitely an imperfect system there needs to be more clear guidlines and landmarks for those of us using chain hoists in a entertainment industry. We don't have the option to wait for something to fail or to put serious back ups on it all the time we need to be sure in our tools and machines at all times.