Are you rigging safely?

[trussmonkey]

I might hasten to add that I often get very concern with the frequency of ads placed on here asking for advise in rigging often complex items. whilst I appreciate that some of the members/guests are amateurs who have know experience or even pros with little or no experience this is no excuse. If you don't know don't do or try. Unlike lighting where if you don't know how to achieve an effect you could probably bodge something together. Rigging is dangerous in even its simplest activities. Only trained and experienced riggers should be rigging any type of temporary structure. Rigging is potentially life ending and certainly career ending.

[Ellis]

Several good points have been made, but the truth I sthat there are shows going on where the (small) amount of rigging required makes it impractical to use a rigging specialist because of the costs involved in travelling to the venue, etc.

 

Companies like Terralec sell stand to truss adaptors. People will see them as an extension to the concept of a T-Bar and will use them. Indeed the stability issues mentoned are probably the same for a fully loaded 6' T-Bar stand. (It is interesting to note that the ratings on Doughty stands seem to only be a vertical loading with no indication of safe working torques)

 

Lighting technicians it particular do find themselves in the situation that they have to rig something to hang their lights from.

 

An investigation of the courses available shows that they are squarely aimed at rigging professionals working on rigs of all sizes, not people who need to do small jobs as part of their work.

 

Maybe one of the training companies might consider offering a suitable course. It may also be worth considering a non-weekday option for those people who have jobs outside the industry and are forced to limit their theatre (or disco) work to evenings, weekends and annual leave.

[robloxley]

With my "Slick" hat on, since it was mentioned in a post - please do not use 'wind up' stands intended for lanterns for supporting Total Fabs/Slick trusses without properly assessing the risks and taking appropriate action.

There are however the likes of the Doughty Zenith and Strata ranges of wind-up stands sold precisely for lifting truss.

[Chris Higgs]

I was careful to state 'wind up stands for supporting lanterns' and to specify TFL/Slick trusses.........specific, like.

There are many trusses and many stands manufactured, and I feel sure that the manufacturers will have tested their products and designed them accordingly.

As a user, you need to be sure that the combination you select is appropriate for all foreseeable circumstances, and in a lot of cases that is doable.

 

As far as training is concerned, anyone producing or supplying such equipment should be able to advise and/or provide training (it may even be free!!).

If the product is CE marked, and I am sure it should be, there is a legal requirement to provide necessary information to use the equipment safely.

 

The confusion and consternation may arise from what you define as rigging.

To me, putting lighting stands up ain't rigging, it is a lighting technician's competence. To others it may be rigging, but who cares?

 

What matters is that it is as safe as you can make it and presents no inherent or foreseeable hazards in use.

Should it all go horribly wrong, you will need to able to prove you were using it correctly, it was designed to be used in that way and that you took all reasonable steps to ensure that you were not acting without due diligence.

[Chris Higgs]

An investigation of the courses available shows that they are squarely aimed at rigging professionals working on rigs of all sizes, not people who need to do small jobs as part of their work. 

 

Maybe one of the training companies might consider offering a suitable course.  It may also be worth considering a non-weekday option for those people who have jobs outside the industry and are forced to limit their theatre (or disco) work to evenings, weekends and annual leave.

I am sure White Light could help?

You may find that weekends are a non starter - we would have to take time off during the week to compensate!

If you are using systems on a non professional basis, I think some of the risks do not equate with the potential value of claims you may face in the event of a collapse or failure, assuming prosecution was avoided and the case was civil.

As far as 'rigging professionals' are concerned, we provide training to as many non-riggers as riggers, in fact.

I would hope that anyone calling themselves a 'professional' rigger had the knowledge and experience to avoid such situations arising in the first place.

[la grande homme]

saw the accident that thirdtap's link refers to at ROH (was downstairs in the Linbury and heard the call go out over the Show Relay 'Ladies and Gentlemen, act III will take place in front of the (closed) tabs' so went up for a peek and it looked like someone had blown up the mainstage!)...very messy and astonishing that no-one was hurt even though it happened during an interval change... it led to an awful lot of the ROH bars being re-appraised and subsequently removed from the rig.

 

An interesting one I've come across this month is related to Hemp Flying... one of our Theatres has three five strand hemp bars (along with 8 winches) in January they were all load tested and the winches came out with a SWL of 250KGs (tested to 375) The hemps however came out at 25kgs each (I only discovered this a couple of weeks ago when I finally got the paperwork)... I spoke to the guy who did the testing and he said that as a person is only rated to lift a maximum of 25 kilos then therefore that was the maximum for the bar (presumable including the bar itself) I said that working on that theory could two people lift fifty kilos and he wasn't sure... could someone clear this up for me?

[andy_s]

a person is only rated to lift a maximum of 25 kilos then therefore that was the maximum for the bar (presumable including the bar itself) I said that working on that theory could two people lift fifty kilos and he wasn't sure... could someone clear this up for me?

so if this is the case, how come the "cough cough" major was lifting well over this in the recent Celebrity Sports Day or whatever it was called...

 

more seriously, I have used the 25kg figure as a "per person" factor - not particularly in flying situations but in other manual handling operations - moving steeldeck, lifting flightcases, etc. My opinion - and I am ready to stand corrected - is that this is innappropriate for a hemp flying system as the lifting techniques involved are very different. In fact it could be suggested that the person is not doing the lifting - he / she is operating machinery designed to perform a lifting operation (admitedly much less sophisticated than Nomad in the Linbury Studio). Is there anyone around from brighton Theatre Royal, or Stratford East, or other hemp houses who can shed light? I'm pretty sure that the Theatre Royal Bury St Edmunds has hemp sets rated at 100Kg - can't remember how many lines this is spread over.

[Dave]

I would regard the SWL of a hemp set as the max load it is rated to carry when correctly tied off. The issue of what is safe when it is being manually hauled is completely different.

 

(Can't remember where, but I'm sure I was once in a venue when the LX bars were hung on hemp sets)

[gareth]

(Can't remember where, but I'm sure I was once in a venue when the LX bars were hung on hemp sets)

The one that most people know due to having toured there is the Theatre Royal in Brighton. I was there myself earlier in the week doing a re-light - if I'd known that they were going to crop up in this conversation, I'd have paid more attention to a large printed sign that I noticed in the stage left wing, giving the exact figure for the rated SWL of their hemp sets ... but I didn't ...

 

And on a side-note ... the prize for the most bizarre counterweight-assisted hemp sets I've ever seen has to go to the Palace Theatre in Westcliff-on-Sea. They're very difficult to describe, but anyone who's ever toured a show into there will know what I mean!

[paulears]

the 25kg limit is suggested in guidelines, as far as I know, not in legislation - male and female limits differ (can't remember how much). If I remember my H&S training this limit is a lift from the floor, as in picking up a box in the office. Most carriers still work on an up to 30kg limit.

 

patrick marks (status quo LD) tells a great story about how they were going to lift a pretty chunky loaded truss, and the riggers weren't happy that the paperwork supplied saying the roof trusses were strong enough was accurate. In the end they watched as the chain motors simply brought the roof down, without the truss moving.

[gil-galad]

Going back to the previous discussion about using stands to support trusses. Doughty do make stands designed specifically for lighting trusses.

 

They are available for hire from HSS but I do not know who else has them.

[Chris Higgs]

There are several companies who make 'stands' for trusses.

On those I can't comment.

 

To re-iterate, please do not use stands made for supporting lights to lift or support TFL/Slick trusses.

The majority of both the ranges are too heavy to use with lighting stands in any case, and it certainly won't be a stable structure if you need to use a truss for its spanning ability.

The fact you can buy the spigot/adapters was the nub of the issue.

 

I am the first to accept you can use a truss between two stands because it looks better than a tube, but you may be playing with fire structurally. What about people being in close proximity? What about the flexion of the loaded truss causing the stands to sway?

If you have to claim on your insurance because someone is suing you for clouting them during the disco/reception/show/exhibition/fashion show/school play you may find that Mr Zurich calls Mr Manfrotto. Mr Manfrotto will say "Your client did what with our product?" and Mr Zurich will decline the claim/put your premium up by 100%/insist you use proper equipment in future.

Desperately trying to be constructive.........

[gareth]

(Can't remember where, but I'm sure I was once in a venue when the LX bars were hung on hemp sets)

The one that most people know due to having toured there is the Theatre Royal in Brighton. I was there myself earlier in the week doing a re-light - if I'd known that they were going to crop up in this conversation, I'd have paid more attention to a large printed sign that I noticed in the stage left wing, giving the exact figure for the rated SWL of their hemp sets ... but I didn't ... :P

Just been back to Brighton to put another show into the Theatre Royal, and I remembered to read the notice this time! Their hemp sets have a rated SWL of 250kg per set evenly distributed, with a maximum 100kg load on each of the three lines per bar.

[robloxley]

Their hemp sets have a rated SWL of 250kg per set evenly distributed, with a maximum 100kg load on each of the three lines per bar.

From my somewhat hazy memory, does this strictly make sense: when applying a UDL of 250kg on a barrel, won't the middle line of the three-line-set be taking about 125kg suggesting each line should have a SWL of 125kg? Feel free to correct me if my maths is wrong; I suppose I've also assumed the locations of the drops to be centre and each end.

Also someone needs to make sure the tie-off cleat has a SWL of 300kg, for when 3x100kg point sources are flown?

[gareth]

Their hemp sets have a rated SWL of 250kg per set evenly distributed, with a maximum 100kg load on each of the three lines per bar.

From my somewhat hazy memory, does this strictly make sense: when applying a UDL of 250kg on a barrel, won't the middle line of the three-line-set be taking about 125kg suggesting each line should have a SWL of 125kg? Feel free to correct me if my maths is wrong; I suppose I've also assumed the locations of the drops to be centre and each end.

Also someone needs to make sure the tie-off cleat has a SWL of 300kg, for when 3x100kg point sources are flown?

All I can tell you is that what I quoted is what's printed in HUGE letters on the SWL rating board in the stage left wing!

 

The long and short lines are not right at the end of the bars - they're a short distance in. The issue of hanging 300kg on the bar is irrelevant, as the max SWL is 250kg - what I was trying to say is that the 250kg is the max load on the bar, and they also have a max load on each line of 100kg. So you couldn't hang a 250kg piece in the space between two of the lines on the bar, as in simple terms this would put 125kg onto each of the two lines which would overload them. I notice that they also had a SWL for the entire grid of 2500kg, and a SWL for each joist (presumably running up/down stage and to which the drop pulleys are attached) of 1000kg. But then, it is made of wood ... :P