mikienorth Posted March 23, 2005 Posted March 23, 2005 Steels are generally harder wearing, which is important when the truss is landed on them. They generally have to be made to suit a particular truss and wrap, since they are not as flexible as spansets. They are generally easier to inspect than spansets, which are very good at hiding holes etc. Many venues will insist that trusses picked up with a spanset have a steel secondary between the truss and the motor, though more and more the safety will go straight to the roof, bypassing the motor as well (pointless dangerous exercise IMHO) <{POST_SNAPBACK}> Sorry to sound a little dumb here, but which is the pointless/dangerous exercise in your opinion, as I read the post I can't figure it out. Again sorry to sound dumb, I just need help on this.
Nick Evans Posted March 24, 2005 Posted March 24, 2005 The practice of putting secondaries on temporary lighting rig in the touring environment. Generally, safeties go on only after the rig has been flashed out and focussed, so local riggers are kept hanging around sometimes until 4 in the afternoon to do 30 minutes work (though they finished putting the points in at 11am). They then have to go away, rest and be back at the gig for a 10:30 load out. They have therefore probably been awake since 6 am when they then have to go back up to take the safeties off again (ie awake for 16.5 hours then go climbing) Whilst I am not aware of any rigger being seriously injured where fatigue was a factor, my personal experience is that if anything is going to get dropped it will be in the first half hour of the load-in or the load-out. Neither am I aware of any incident where a motor has failed and dropped the load since people stopped touring Verlindes. Furthermore, safeties deny rescuers the fastest way of getting to an unconscious casualty on a truss (e.g. a truss spot operator or truss monkey) and that is to drop the truss in. Safeties are also the cause of many an incident. I seen lighting trusses and PA clusters (esp with American crews) run down onto safeties on a few occasions. If you are not careful, ferrules can get wedged into the female lugs of trusses, this is a nightmare and it is often quickest and safest to cut the steel (only seen it done once but I have heard of other occasions) If anyone can put me straight on when a steel secondary fixed to a roof has provided a direct (as opposed to implied) benefit I am prepared to alter my opinion but personally I think that a truss with steel pick-ups lifted by a motor that uses steel fixings to the roof does not need a secondary support <<Puts on tin helmet, prepares for incoming fire>>
Bryson Posted March 24, 2005 Posted March 24, 2005 Neither am I aware of any incident where a motor has failed and dropped the load since people stopped touring Verlindes. I think the good people at Verlinde might thank you for at least qualifying that with a model number... Otherwise, very interesting point.
gareth Posted March 24, 2005 Posted March 24, 2005 Hmmm. IANA rigger, but what you say makes quite a lot of sense, Nick - especially the bit about dropping the truss being possibly the quickest/easiest way to gain access to someone who's up there and who needs urgent medical attention for one reason or another. That's not something which had ever occured to me before, but it sounds like a very valid consideration.
Nick Evans Posted March 24, 2005 Posted March 24, 2005 Good point Bryson:I think the good people at Verlinde might thank you for at least qualifying that with a model number...The older stuff, 54 / 104 / 108 / 204 etc. I don't have much experience of the newer stuff though I have heard that some of the newer stuff is better than the old stuff. I do seem to recall something that they sold that had no hooks though.....
mikienorth Posted March 25, 2005 Author Posted March 25, 2005 Thanks Nick, it is the use of safeties you disagreed with, not the way they are affixed, which is where I was confused.The points you make against their use are good ones, however, in the venue I work in, every flown truss tends to have safeties used, I thought it was a legal requirement, or if not, one that licensing will ask for.In my venue shows tend to be around for a little longer than a day, more often a week at the shortest, so rigger fatigue is less of an issue.Are they a legal/licensing requirement, and, knowing there are other options such as load arrestors and double braking, are either of those options a suitable substitute.Should I be asking this in a topic about roundslings?
Chris Higgs Posted March 25, 2005 Posted March 25, 2005 For what it's worth....There is no 'best' way to sling a truss, be it with steel or fibre slings.They all have pros and cons, slings and trusses."...when you land a truss on them...." was mentioned. I would suggest a roundsling will be less damaged than a steel, actually. Generally we avoid landing things on slings, chaps... The question was if there was a correct or incorrect way to sling a truss with a roundsling. Answer, there is; when the sling won't damage the truss (off-node loading, typically) and when the truss won't damage the sling (sharp edges, little gaps which the sling may get dragged into and compressed or cut).The question of heat is a moot point. There is no doubt polyester melts and around 80 Celcius is the typical figure quoted. Steel is about 10 Celcius higher, but how quickly does a fire increase in temperature?Aluminium loses around 45% of its strength when heated to 200 Celcius and if it is laden at the time, I wonder which is nearest to the flames?Steel is combustible and will burn rather well at the right temperature.As far as I can gather, the steel/roundsling thing is a hangover from heavy metal pyro extravagansa, North American colleagues reckon we "started it" in Wembley. Secondary suspensions are one way of stopping a two motor truss (for example) falling. Redundant suspensions are another (enough stuff to hold up said truss should one point fail).IMHO it is rarely the kit that will fail, it is usually the twerp who thinks he knows how to carry out a lifting operation.A completely independent suspension is undoubtedly the best practice.If the secondaries prevent a truss being lowered in a rescue situation why haven't you got another means of rescue? Not using secondaries (unless there is sufficient redundancy) because it makes the rescue thing difficult is not a valid excuse.You shouldn't really be clambering around on trusses routinely unless it is a safe system of work, either. The Work at Height Regs may well effectively outlaw the practice. I think Bryson is quite right about what was said about Verlinde.Nick, what a statement! Sold without hooks? Older stuff "dropping" loads - you mean the motors weren't ordered, prepped or serviced properly, presumably? Or perhaps the guys using them didn't really know how to use them. Like "eating" chain, presumably? (No they don't, when you use them right. You can easily jam a Lodestar, too.) I am not aware of the installation of 'safeties' ever being dangerous.Sounds like an excuse to me.I suspect that this comes from the same school as pulling up steels and wrapping them around beam or truss until they are 'tight' and choking them back with a shackle?Copying what you see rather than learning the trade.As for fatigue, well that's a personal call, but any responsible person will either plan to avoid getting tired (you don't expect to be putting on safeties?) and make the work as easy as possible to avoid fatigue. Tell me I'm wrong...
Nick Evans Posted March 26, 2005 Posted March 26, 2005 The question of heat is a moot point. There is no doubt polyester melts and around 80 Celcius is the typical figure quoted. Steel is about 10 Celcius higher, Are you suggesting that steel melts at 80+10=90°C? Not sure about that. I was refering to research (which I had heard about, therefore anecdotal) which was done on loaded steels and polyester roundslings subjected to heating and combustion, where the alloy crimps were seen to expand thus releasing the load. Steel does not melt at 90°C.Steel is combustible and will burn rather well at the right temperature. Not quite sure but I believe that would be somewhere beyond 1400°C (and therefore I contend, beyond the scope of this discussion). The core of a steel wire rope may well degrade long before that, and any oil on the steel will certainly burn off, but to burn through a steel wire rope you need a gas axe.Generally we avoid landing things on slings, chaps... And back in the real world, it happens all the time. If the truss is picked up by the bottom chord and it has no wheels what else are you supposed to do? Run around and put bits of timber underneath the truss? I am sorry but truss lands on slings all the time.Secondary suspensions are one way of stopping a two motor truss (for example) falling. Redundant suspensions are another (enough stuff to hold up said truss should one point fail). IMHO it is rarely the kit that will failAs I said, I have no knowledge of this ever happening due to failure of the hoist or rigging.it is usually the twerp who thinks he knows how to carry out a lifting operation.As I said, I have seen numerous occasions where safties have caused an incident.If the secondaries prevent a truss being lowered in a rescue situation why haven't you got another means of rescue? Not using secondaries (unless there is sufficient redundancy) because it makes the rescue thing difficult is not a valid excuse. Would you argue that it is best to rescue someone from a truss which is up or down? In the time it would take the IRATA rescue technician to don harness and check kit, and ascend to the truss, you could have the truss on the floor. If the casualty is unconcious and non breathing, breathing must be restored in 4 minutes. How is this to be achieved if the casualty has fallen from the truss and is now suspended from the horizontal safety line by a 1 metre lanyard the wrong side of a lamp bar? Rather easier if the truss is on the floor. I know it is quite often not as easy to get the truss to a working height, because of set, backline etc but if the casualty is hanging below the truss then you don't need to get the truss to working height.Nick, what a statement!Sold without hooks? Yes as I said, I seem to recall some type of newer verlinde that has an eye (for a shackle) but no hook, however I stand to be corrected. The sort of fixing that is ideal when hanging a motor "motor up" as one would do in a factory using a beam trolley for work placement, where you do not want the motor to spin because of entanglement in the power cable.I am not aware of the installation of 'safeties' ever being dangerous. When safeties are put on they cannot all be adjusted to exactly the right length because it is a fixed length of steel with a shackle on the end, wrapped around the PA or lighting truss. The top of the safety will be taken to the most suitable beam above the suspended structure. I have never seen anyone bridle a safety. Therefore, when something is lowered onto a safety (yes, a muppet on the buttons) it will be a) not level and b) if it is curved, pulled out of alignment. Therefore the structure is subject to bending in the horizontal and vertical planes. The most graphic example I can think of in my personal experience is when an American PA system which uses large aluminium structures was dropped onto its safeties. The 2 halves of the bumper were lifted by 2 motors each, but the 2 halves were held in alignment by a small ratchet strap. When the load was applied to the safties, the bumpers were pulled out of alignment such that the ratchet strap broke, and fell 50' into a cable trunk. My point, safeties can cause incidents.I suspect that this comes from the same school as pulling up steels and wrapping them around beam or truss until they are 'tight' and choking them back with a shackle? How do you apply a safety then? Yes you can use clutch chains, or deck chains, or chains of shackles but what tour carries a deck chain per point to do safeties with? I have never seen anything else but wrapping it until it is tight. I am always willing to learn.Copying what you see rather than learning the trade. What an arrogant statement. From whom? When I started rigging, the way to learn was by watching others, seeing what worked, who was an idiot, and developing the ideas of others and by doing the work, because that was how you learned. How else could one learn at the time? I worked for rigging companies (the big 2 at the time, both of whom used truss steels all the time) and lighting companies (also the big 2 at the time) as a rigger. By listening to my elders and betters I learned what was good practice and what was not. By asking questions I found out the reasons certain practices were frowned upon. I still use this method of learning today, and so I am still learning from what I see. I am smart enough to know that there is always a different way, and that others can show me things (no matter how long I have been doing this). Too much wine methinks. Apologies, from this point forward the quote function refused to work.. "As for fatigue, well that's a personal call, but any responsible person will either plan to avoid getting tired." Not always practical. Promoters have their favorite riggers, they will quite often book the same guys to do 2 or 3 different venues on the same tour. The touring bloke walks in, who has had a nights sleep on the bus, only to discover the same faces as he said goodbye to not 6 hours (and 200 miles) ago. Not safe. Furthermore, it is highly unlikely that promoters will start booking different crews for the in and the out, half the time they struggle to get enough guys together in the first place. My point is that the rigging points are normally up and finished by 11 or 12, the riggers then have to hang around until 3 or 4 to do 30 minutes work, rather than leaving the building to get adequate rest. And yes, you can expect to put on safeties, a reasonable time after the truss has been trimmed, not 4 hours later. Verlindes and uncommanded moving loadsA long time ago the only Verlindes available in the entertainment world were the 54/104/108/204 type motors. These all had a nut which was readily accesible on the outside of the motor which adjusted the load a motor could carry. On more than one occasion I have seen Verlindes slip. It was probably due to knowless people adjusting said nut to perform a particular lift, then adjusting it again (back down) before the motor went back to the yard. Generally motors were proof loaded once a year, as part of the certification process. A motor could therefore go a very long time with it's load calibration incorrectly set.When you move a big truss, especially something like a multiple span box truss with multiple motors per span, the heaviest points move the fastest (not by a lot, but it does not have to be) In this case, the loads on the individual points are changing. It is possible that a motor which has happily held the load all day (because when it was going up it was slipping ever so slightly) will end up carrying more load than it can lift, even though the load is below its rated capacity, because someone has tampered with the motor in the past. Under these circumstance, as soon as the weight is greater than the static friction of the clutch, the load will descend (dynamic friction being somewhat lower than static friction.) It will continue descending until the load is less then the dynamic friction (this occurs because the load that the motor was carrying is now being borne by the rest of the motors on the grid. Note: this has nothing to do with the people currently operating the kit, it due to the actions a) of the individual who messed about with the kit, and b) the company, which did not load test the motor every time it went out of the door. I am not familiar with modern Verlinde products, every tour or show I have worked on in the last 6 or 8 years has used Lodestars. By the comment"motor has failed and dropped the load since people stopped touring Verlindes." I was refering specifically to the 54/104/108/204 range of motors. I do not even know if these motors are still in manufacture. I am in no way saying that the current range of Verlinde products is unsuitable for the entertainment industry.
Chris Higgs Posted March 27, 2005 Posted March 27, 2005 Interesting and vociferous points.I don't agree with much of it, but I take your point in some cases and respect your opinion in any case.The temperature information was not clear, sorry. The figures I quoted are the figures usually used by manufacturers as maximum operating temperatures. The expansion of the ferrule is one of the reasons, I have met a rigger who actually saw this happen in a fire in Israel a few years ago.(qv Dr. Randall Davidson's stuff for USITT/ESTA) In the 'real world' roundslings are less damaged by having trusses land on them than steels. In either case, you don't expect the slings to last very long, so manage them accordingly. A rescue plan doesn't have to be snatch rescue from above. It could be one of several methods, including powered access where possible.The Work at Height Regs will have impact here, too.One well known manufacturer quotes a clearance of 9m for horizontal fall arrest lines.I can't go into it here because I work for and have shares in a company that markets an alternative, but a horizontal line may well not be suitable on a flown aluminium truss. The fall arrest components are fine enough, check the end anchorage requirements against the truss spec.. I have spent nearly the last 10 years trying to help people learn about rigging, hard graft, many miles travelled, many hours spent researching, writing, etc.. I hope it isn't arrogant, and I resent the too much wine comment, I have to say.The safety profession refer to what I called "copying what you see" learning as 'sitting with Nellie'; the idea being that because it is seen to be done, it is safe/acceptable/tolerated, etc. and one is less likely to discard information thus gained unless it is plainly crazy. Because there has been little formal training either available or taken, there is a huge amount of ignorance about rigging matters in general. Much of the information coming to our attention is from manufacturers who are catching up with what we are doing with their gear. Personally, I asked CITB to tailor a course so I could be 'certified' by them for anything relevant which stood me in good technical stead. Any additional training I could find along the way I took, inspection, PPE, work at height, etc..I have to say that in many, many cases, what I learned conflicted with what I knew from experience (in other words what I had seen on site).30 something years later, here I am trying to pass this knowledge on for a living... Like you, I worked for most of the rigging companies at one time or another (I still carry out training for many of their antecedents) and with hindsight strongly dispute they were good places to learn. I gained a lot of experience but not too much knowledge.I have seen supposedly good riggers drop shackles from heights onto concrete and re-use them, choke a steel off node on a single chord and call it a safety, use loadstraps as secondaries, rig inertia reels under a truss on a choked roundsling from a single chord, use PVC tape instead of R pins - I could go on. The reason? They had guessed, used 'common sense' and luckily never had need to rely on the safety of any of them. In many cases I shudder to think what may have happened on many jobs in the late 70's and 80's if it all went horribly wrong. As far as the idea of hours being monitored, no matter how silly you may think it, the law protects us from being pressured into doing things we shouldn't do, including hours worked. If you believe it is 'part of the job' then you are responsible for taking on the work in the knowledge you may be too tired.The new Regs will help here, too. Riggers should know that what you describe (and I'm not for one moment saying it doesn't happen, but it need not IMHO) is not safe, not fair and technically illegal. If they had an accident they would find out. Another example of 'sitting with Nellie'. If you accept "that is what happens in the real world", there will be no progress. You're either an employee, in which case you should not be expected to do what you describe (poor planning and not a safe system of work) or self employed, in which case you need to plan the work better yourself. The Verlinde point is fair, there were many numpties who would adjust the clutch nut. But I am sure you agree it wasn't the fault of the manufacturer. but the user. The Litachain range is no longer manufacturered, you're right.The higher profile 'accidents' were generally hook or chain related AFAIK, and again not the fault of the manufacturer. The hoist was not designed for the use we made of it, of course, any more than the Lodestar was. The lug type of suspension is most common, I believe, on the Liftket/Chainmaster/Logiclift motor, although I'm sure most hoist manufacturers can supply something similar.(I understood you to mean that the hoists had been sold without hooks)
Nick Evans Posted March 28, 2005 Posted March 28, 2005 A rescue plan doesn't have to be snatch rescue from above. Though I am not rescue trained, I know of 4 methods for rescuing a suspended casualty1) Rescue from above by recovering the casualty to the truss. Very hard work for the rescuer, the casualty may be the wrong side of the lamp line.2) Rescue from above by abseiling to the casualty, securing same and detatching from safety line, abseil to ground. Very dangerous for rescuer and rescuee. Time consuming, takes a long time to set-up. 3) Rescue from below. Powered access from below may be the quickest way to reach the casualty. If the machine is in the building, and if seating has no already been laid out, barricade erected, the audience are in etc. More difficult when the arena is full of set carts, flight cases, the snake pit is open etc. Very little relevance if the casualty is downstage of any backdrop in a venue which has fixed seating or a raked floor or a sprung floor. Tours would need to carry their own access, since local suppliers cannot always be trusted or are able to match requirements, the lack of powered access would preclude assembling the lighting rig because there is no means of rescue from same.4) Rescue from below by moving the floor up ie bringing the truss down.I would say method 3 is best, where practical, followed by method 4. 1 and 2 do not allow the casualty to be treated in under 4 minutes.In the 'real world' roundslings are less damaged by having trusses land on them than steels. Personally as I stated earlier I believe that steels are harder wearing (which is why we use them to fix points to the roof, not spansets) and they are also more easily inspected (because you should be doing this every time they are used). A problem with a prescribed system of learning is that it is rarely very practical. Students very rarely attend courses to seek knowledge these days, they go to get a qualification. They do not try to understand something, they try to gain the knowledge required to pass the assessment. There is very rarely any assesment of a candidate's attitude and approach, so long as the boxes get ticked. Furthermore, training systems can sometimes provide a false sense of security (I have the piece of paper, of course I can do that), or where the training has been funded by employers, " we have paid to train you, you can do that." Not that I am saying training is a bad thing, but it should be backed up with structured supervised practical work over a number of years. Possesion of a rope and harness means that you own a rope and harness, nothing more. There is a danger that someday quite soon that unless some form of acces is available, it wil not be possible to rig and maintain flown touring systems simply because of regulation being applied which serves no purpose. (I have known a few people who have died who toured, either HIV, suicide, motorcycle accident (3) and cancer. No fallers and I hope it stays that way). Back to the subject of safties. As I stated previously, I am not aware of any flown system failing once it had reached trim and been trimmed. Any incidents I have seen have been when a structure has been moving, or stopped during a sequence of moves. Under these circumstances safties would serve no purpose, unless you propose that every point should have a moving safety.All safety measures are the balance of risk and consequence. If it could be shown that the risk of a motor or the associated rigging failing is mathematically remote (say,10^-6, once every million years) would you not agree that secondary steel safeties provide a degree of redundancy which is not required and furthermore, by there use, increase the risk of other hazards occuring. (Before anyone says it, you can have too many safety systems. Aircraft could always have more in the way of redundant computing, heavier (and therefore stronger) components etc, but they would become to heavy to fly, hence they would loose their function.I suspect that this comes from the same school as pulling up steels and wrapping them around beam or truss until they are 'tight' and choking them back with a shackle?I am still wondering how safeties should be fixed to a roof if not by wrapping the beam and chocking the end back to the steel (pin in the eye of course) As far as the idea of hours being monitored, no matter how silly you may think it, the law protects us from being pressured into doing things we shouldn't do, including hours worked. The entertainment industry is very time sensitive. If a load-in goes pear shaped because of some local promoter SNAFU (wrong access, no keys, no local riggers, trucks got stuck in Switzerland etc.) no-one has yet turned around to a production manager and said "well we have been on duty for 10 hours now, we are due a 6 hour rest period, we will be back at 10pm" because there are deadlines which will not change. Yes the show can be cancelled but that is not a decision a rigger can take, because the commercial implications are beyond those his insurance company can accept reasonably. You put you head down and do the last hours work then. And another thing, if you did turn around and say you were leaving because you had done your 10 hour shift, sit back and watch the work drop off, because there will always be someone with a harness and a bit of string ready to do your job.
dtgorton Posted March 29, 2005 Posted March 29, 2005 I am still wondering how safeties should be fixed to a roof if not by wrapping the beam and chocking (sic) the end back to the steel (pin in the eye of course) Just a couple of quickies on this:1) I wouldn't like to see a steel choked back on itself and be expected to take any load; what's wrong with making up a basket for the safety, or even connecting to the top-steel masterlink?2) I heard tell of fibre roundslings manufactured with a telltale in the cloth sheath. This telltale thread was supposed to change colour if it had been overloaded (I'd like to think from a greasy grey-black to fluorescent yellow stamped with "I've been overloaded, cut me in half & throw me away" but am thinking it's probably beyond the technology of the day). Is this an urban myth? Dave
Nick Evans Posted March 29, 2005 Posted March 29, 2005 In my extremely humble been doing it wrong all these years opinion: If you choke a steel around a beam properly it will still takes load however you must be careful to ensure there is no lateral load applied to the ferrule. The fact that the shackle acts on the steel is irrelevent. The thimble is there to prevent wear on the rope, it does not make it any stronger. This is why soft-eyed steels use the same size rope as hard eye steels, unless the man from Bridon Ropes and the bloke at Rope and Marine Services were both wrong when I was asking about developing an alternative to k-links using asymmetric interlinked hard eye steels. There is nothing wrong with making a basket up and doing it that way, certainly in the concert touring world you never see it happen. It takes longer, and you need to have some form of adjustment in it to make the safety as tight as possible (without actually taking load) in order to reduce the dynamic load should a falling load ever be applied (the shorter the fall, the lower the kinetic energy which must be managed). Plus, the more you have to do in the air, the longer you are up there. You can't go into the masterlink if it forms part of the primary suspension system because the whole point is to bypass the point in it's entireity to provide a redundant system in case of catastrophic failure of the point, motor and pickup of your choice. BTW, what exactly are you calling a master link? I had always taken it to mean an 'O' ring but I am a little confused as I don't often see the need for 'O' rings except for bridles with more than 2 legs. (I am not taking the wee, people talk about different things different ways.) I have never heard of spansets with overload tell-teles, but most of the spansets I have ever cut up were disposed of because they showed signs of damage for instance cutting, chaffing, burning etc. and not because they had been overloaded. The sheath of a spanset does not take the load, it is there to protect the soft fluffy (but very strong) fibres within. Sadly these load bearing fibres cannot be seen through the sheath.
emj Posted March 29, 2005 Posted March 29, 2005 When I started rigging 10 years a go or so, yes a lot of things where chocked with better infirmation and better practices this is a lot less now. Having had 2 years working for a major rigging company chocking was bad practise. I would not say never done but rarely Reasons for this are it greatly reduces the life of the steel and the safe working load is reduced up to 30%(I seem to recall). And I have come across Round slings with thread throw them so you can tell if they have been overload. But can't remember where
Chris Higgs Posted March 29, 2005 Posted March 29, 2005 Rescue: I am trained and often provide rescue training. You're right, but delay = bad news, you have to balance need against risk.Unconscious person = rapid rescue (irrespective of other injury).Secondary suspensions or a set on stage = delay.Powered access probably always best (but if the is a MEWP on site, why is someone climbing on a truss?) Secondary suspensions would be best made as a basket and shortened with a clutch chain.In my brief research since your last post, both the major rigging companies in the UK regularly send out clutches/STAC for precisely that purpose.I don't propose to go into it here but for information on secondaries that may work I would point you at Harry Donovan's book, BS 7906 and my books .I quite agree that if the secondaries are made the way you are familiar with, one may as well not bother because they probably won't work. A choke may weaken a steel as much as it would a roundsling, and if the ferrule is in contact with the beam edge it will be even weaker.Slack should not exceed 150mm.With respect, just because you have no first hand knowledge of something doesn't mean it doesn't exist or can't happen.Safety measures are a balance of severity and probability, actually. The law requires measures taken to be proportionate to risk, not the perceived risk.As far as a steel being stronger, it has a factor of safety lower than a roundsling and is damaged more by tight bends than a roundsling. My point was more to do with crushing because an 11mm steel will present a 'fulcrum' whereas a roundsling will be flatter and often 'disappears' into the floor irregularities except in a truly flat floor and a truly straight truss. BTW, who is 'we' in q. ''why we use steels...''? Ref. training, Mark Armstrong, Eric Porter and I have been working with PLASA for over 12 months to develop a rigging qualification which also requires documented work experience. IMHO, if you are worried about your employers using someone with a harness and bit of string in preference to using trained people who know their own limitations, should you be working for them. If you are genuinely self employed (cue Lightnix) you would be breaking the law.This is getting interesting! There are 'Twinflex' slings with telltales and a fibreoptic trace, yes.There were two steel K links produced. One was a 2 ton steel in interlinked 10 x 2' circ grommets. Fantastic, used them to hang heavy PA a lot.Second one was a chain of 10 traditional cable laid grommet slings made in 4mm black PVC wire rope. Worked a treat.When the Machinery Directive came in, they had to stop. With regard to baskets on secondaries I reckon in 30 years I have only choked steels if the beams were big and the steels were 13mm+.Don't get what you were saying about soft eyes?
Guest lightnix Posted March 30, 2005 Posted March 30, 2005 Roll on the National Rigging Certificate B-) If you are genuinely self employed (cue Lightnix) you would be breaking the law.<{POST_SNAPBACK}>I don't think there's really much more I can / have to say on that subject. It's all there in black and white, on this forum and many other sites, for various individuals and "companies" to make up their own minds on how to proceed.
Recommended Posts
Archived
This topic is now archived and is closed to further replies.