paulears Posted August 28, 2014 Share Posted August 28, 2014 Just got a motor rigged from the grid for a production, that's going to have an aerialist dangling from it. It's not a self climber, so is happily and safely rigged, but the idea seems to be to lift up the performers kit to get it to clear the pros when not being used. Is it normal to use CM stuff for aerialists? I thought it would be a straight drop from the steelwork, rather than faffing around with motors? I figured you'd just use a second lightweight line to pull it up from the main suspension dead? Link to comment Share on other sites More sharing options...
top-cat Posted August 28, 2014 Share Posted August 28, 2014 Lifting performers? No. It says it explicitly on the side of a CM hoist that it is not to be used for lifting people. If you want to be backed up, you'll literally find it written on a black sticker on the body of the hoist. If it's being used for suspension only, it's one of those unclear areas. I would say there, it could be suitable, subject to thorough and competent risk assessment and calculation that the forces imposed by the aerialist are within the tolerances of the hoist. Your point about the second line is fine, I guess having it on a hoist means it's a button press that doesn't require a line running around the stage somewhere or somebody stood in the grid. You could still do it on a hoist, but the difficulty would be in ensuring you only ran out a little more chain than needed to put the weight on the steel. This would be easiest achieved by setting the hoist limits an running it from limit to limit. But yeah. If say, legit, if properly risk assessed and the hoist deemed suitable for the forces imposed. Link to comment Share on other sites More sharing options...
ImagineerTom Posted August 28, 2014 Share Posted August 28, 2014 It's highly unusual to have a performer directly hung from a chain hoist in this way, as you say the convention is to dead-hang a point and use a non-rated "brailing line" to move it out of the way the rest of the time. If this motor arrangement is specifically what the aerialist has requested then go with it but personally its not a configuration I would use, recommend or ever expect to see in use. I'd have to do the sums but I can't imagine it doing the hoist a lot of good either - they're designed for fairly sedate predictable loads operating in one fixed plane, almost any sort of aerial performance involves lots of snatches / load spikes, twists, turns and rapidly changing sideways loads which are all well outside the normal operating parameters of chain hoist. Link to comment Share on other sites More sharing options...
mackerr Posted August 28, 2014 Share Posted August 28, 2014 It's highly unusual to have a performer directly hung from a chain hoist in this way, This exact setup is used regularly with performers on hanging silk ribbons. They walk out on stage, grab the silks that have been lowered in and get lifted to performing height. The motors are generally rigged "motor up" to keep it out of sight. I don't doubt that CM (and other manufacturers) has tried to limit their product liability be specifying that the motors may not be used to lift personnel, but it is done every day. I have been on many events with these type of performers using this type of rigging. Mac Link to comment Share on other sites More sharing options...
Seano Posted August 28, 2014 Share Posted August 28, 2014 Is it normal to use CM stuff for aerialists? I thought it would be a straight drop from the steelwork, rather than faffing around with motors? I figured you'd just use a second lightweight line to pull it up from the main suspension dead? Not normal, but not very unusual either. A trick line exactly as you describe would be the more usual approach - quicker, cheaper and more convenient to rig (and you're not limited to striking the silk or whatever at a snail-like 4m/minute). Assuming there are no guy ropes (there aren't are there?) - regarding loads on the motor etc., (whether the performer is being lifted or merely suspended) while it's not 'best practice' exactly to use a bog-standard model L lodestar for this kind of thing it's definitely not something I'd be losing any sleep over. There's no way a single aerialist is going to apply more than a fraction of the hoist's SWL, even as a transient 'spike' type thing. Using the hoist to lift some kind of aerial rig and take up a strain against downward guy ropes definitely could overload it though, hence the question. Some things to watch out for that haven't been mentioned thus far: As with pyro, it's *essential* that whoever is operating the hoist during the show has a clear view. If it's a bog standard hoist on a bog standard controller there are safety features lacking that you would ideally want on a powered performer flying rig, so the vigilance of the operator is all you have left. Even with a bog standard controller it's often not hard to incorporate a remote e-stop - worth putting one with in reach of someone (stage manager?) who can bring a second pair of eyes to bear. It would be best if the motor is rigged in such a way that it can't rotate. (The usual way to do this is to use a hoist with a non-rotating suspension/hook, and to rig it with a beam-clamp or directly at the apex of a bridle.) If a hoist rigged motor-up does rotate there's sometimes a danger that it's cables could end up wrapped around the lift chain and subsequently get dragged into the chain port and eaten. Needless to say that would be bad. Ideally the motor should have a close-fitting (and amply sized) rectangular chain bag to mitigate against the risk of chain spillage. You definitely don't want an old-fashioned Klein bucket full to the brim. Link to comment Share on other sites More sharing options...
paulears Posted August 28, 2014 Author Share Posted August 28, 2014 That's pretty much how it's been rigged - the motor has a very large safety and cannot spin, and is hanging just 300mm or so from the steel. I appreciate the info guys. Looks like all is well. I've not interfered, as they seem to know what they're doing - but I'd not personally seen motors rigged for this, and had seen the stickers! Cheers\P Link to comment Share on other sites More sharing options...
top-cat Posted August 28, 2014 Share Posted August 28, 2014 It's highly unusual to have a performer directly hung from a chain hoist in this way,They walk out on stage, grab the silks that have been lowered in and get lifted to performing height. If this means the performer is being hoisted on the silk, then yes that is in breach of the manufacturer's regulations (and probably also of LOLER since that requires that equipment used for lifting people is designed for that purpose). Link to comment Share on other sites More sharing options...
ImagineerTom Posted August 28, 2014 Share Posted August 28, 2014 This exact setup is used regularly with performers on hanging silk ribbons. They walk out on stage, grab the silks that have been lowered in and get lifted to performing height. The motors are generally rigged "motor up" to keep it out of sight. I don't doubt that CM (and other manufacturers) has tried to limit their product liability be specifying that the motors may not be used to lift personnel, but it is done every day. I have been on many events with these type of performers using this type of rigging.<br style="color: rgb(28, 40, 55); font-size: 13px; line-height: 19.5px; background-color: rgb(250, 251, 252);"><br style="color: rgb(28, 40, 55); font-size: 13px; line-height: 19.5px; background-color: rgb(250, 251, 252);">Mac Perhaps I should have added the caveat "on this side of the Atlantic" to my statement then, as TC mentions it's also right on the fringes of the regulations / manufacturer's recommendations and just not "the way" aerialists are taught or generally work over here. I don't doubt there are exceptions but since there are very few training schemes and only a few dozen performer riggers/rigging designers over here the style and practices of the industry are fairly standard and homogonised. Link to comment Share on other sites More sharing options...
kerry davies Posted August 29, 2014 Share Posted August 29, 2014 Pedantry dictates that I raise the spectre of jobsworthism and point out that CM Lodestar safety instructions specifically say; "DO NOT use this equipment for lifting people. DO NOT leave suspended loads unattended. The operation of this equipment must at all times be done by trained staff." Or worms to that effect. That then raises the even more ghastly prospects of insurance and how to justify ones actions in any possible subsequent legal proceedings. Sorry to be an old fart but them's the realities. The practicalities are that there is a perfectly adequate, cheaper more effective way of doing the same thing so why use a hoist which specifically forbids the practice? NB; I may well have not fully understood what is actually being done here so bear with my misconceptions, please. Link to comment Share on other sites More sharing options...
top-cat Posted August 29, 2014 Share Posted August 29, 2014 Pedantry dictates that I raise the spectre of jobsworthism and point out that CM Lodestar safety instructions specifically say; "DO NOT use this equipment for lifting people. Kerry, as I alluded to in my first post, the reason that this situation can be a bit blurred is that whilst CM do prohibit the lifting of people on their Lodestar hoists, they don't explicitly prohibit the static suspension of people from their hoists. LOLER is the same - it covers lifting activity, but not static suspension. People being suspended on entertainment chain hoists is reasonably common - Riggers climbing on a mother grid - that is people supported on hoists. Albeit several, but it's still kit which fundamentally states it is not for lifting people. Lampies doing a climbing focus - same situation. As I said, I think it's one of those things which is subject to risk assessment by a competent person and looking at what the alternatives are, and what inherent risks they possess. I mean if the options are climbing up and down truss ladders all day, or riding the truss... I think your risk assessment could account for the fact that whilst your motors are not explicitly for lifting people, the risk of a fall from height presented by riding a truss suspended on several hoists with an 8:1 safety factor is genuinely less than that of continually climbing truss ladders which, whilst designed for purpose, will present issues such as fatigue and the fact that fall prevention is not really available, only fall arrest - and that falling onto an inertia reel would then require a rescue which would be a hazardous operation to both the fallen and the rescuer. As you know as well as anyone, the HSE are supportive of genuine risk assessment procedure and finding the safest way of doing something; and sometimes you may be in a situation where using a piece of equipment slightly outside it's scope of purpose, but still well within what is known to be a safe environment; is safer than following the rules to the letter and creating greater inherent dangers by doing so. And in these instances I hope that the HSE would support your genuine aim of reducing the dangers in the workplace. Link to comment Share on other sites More sharing options...
Seano Posted August 29, 2014 Share Posted August 29, 2014 .. LOLER <snip> requires that equipment used for lifting people is designed for that purpose Not true, there's no such requirement expressed in the regulations. Pedantry dictates that I raise the spectre of jobsworthism and point out that CM Lodestar safety instructions specifically say; "DO NOT use this equipment for lifting people. DO NOT leave suspended loads unattended. The operation of this equipment must at all times be done by trained staff." a) The subject of this thread (kinda sorta)b) Happens all the time, on every gig everywhere, and nobody ever turns a hair. Funny old world innit. Mackerr is quite correct. In a way CM have been having their cake and eating it for decades, cheerfully selling countless thousands of Lodestars as the good old model L came to totally dominate the live events industry worldwide and packing each one off with an owners manual that says "you cant use this for that!". Link to comment Share on other sites More sharing options...
top-cat Posted August 29, 2014 Share Posted August 29, 2014 .. LOLER <snip> requires that equipment used for lifting people is designed for that purpose Not true, there's no such requirement expressed in the regulations. I didn't say it has to be designed explicitly for that purpose. But it has to be designed in such a manner that it meets the criteria laid out in Paragraph 5 of LOLER. It is not safe to assume that all lifting equipment does so. It's irrelevant though, my post was mainly about the sensible stance for lifting people with hoists not explicitly designed for that purpose and clearly there are times when it is acceptable. Link to comment Share on other sites More sharing options...
mackerr Posted August 29, 2014 Share Posted August 29, 2014 Pedantry dictates that I raise the spectre of jobsworthism and point out that CM Lodestar safety instructions specifically say; "DO NOT use this equipment for lifting people. DO NOT leave suspended loads unattended. Does that pedantry also require you to point out that apparently you must lower all motor suspended equipment to the ground each night? I know we don't do that over on this side of the pond. Mac Link to comment Share on other sites More sharing options...
top-cat Posted August 29, 2014 Share Posted August 29, 2014 Does it say "do not leave suspended loads unattended" ? I've never seen that. It would be quite impractical for any show which goes on for longer than a single night, or even house trusses. Link to comment Share on other sites More sharing options...
david.elsbury Posted August 29, 2014 Share Posted August 29, 2014 If it does, surely the best option is to bypass the motor with a steel. Of course, how practical this is would vary depending on your situation. Link to comment Share on other sites More sharing options...
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