Temp Bar Install

[Jambo_UK]

Hi everyone,

 

Basically I just want a second opinion I have just taken over a youth project which does a monthly band night. Basically the thing I want a second opinion on is the way they rig a temp bar. Basically if is two pieces of bi-lite trussing rigged to the Roof beams with 4 steel cables rated at WLL 200kg Each and also a secondary 4 steel cables rated at the same rating. All the Steels are connected using 150kg shackles on each line. A link to a drawing of the structure is included. The guys that do the set up are experienced as they do a lot of local event lighting and sound and they have the normal 10m PLI, 10m Employers PLI and their own Accident Cover.

 

From my experience I think this is a safe rig and method but just wanted to double check other peoples opinions. The reason I want the second opinion this will be the first major project for me to work on and I want to be check if this is the correct way and not look stupid when I challenge them.

 

Thanks for the help

 

http://www.hdlma.co.uk/forum/download/file.php?id=66

 

Notes:

 

The Ceiling Strut (RSJ) it is attached to has been checked and can support a 500kg load and is 4m in the air

 

The Steel Cables and Shackles are replaced every six months and they are ordered direct from CPC.

http://cpc.farnell.com/jsp/search/productd...jsp?sku=ST00897 (shackle)

http://cpc.farnell.com/jsp/search/productd...jsp?sku=ST00914 (steel)

 

The total Rig that is connected weights 24kg and this is spread across the two sections evenly so 12kg on the left and 12kg on the right according a couple of grams for different cables.

 

All the lanterns attached have their own safety bonds including the gel frames.

 

 

PS. The venue is due to have bars fitted to the venue in the next year or so and they and I quote said they would directly attach IWB to these struts and did a quote for a rig double this size, 16 x par 64s longs.

[Seano]

From my experience I think this is a safe rig... ...I want to be check if this is the correct way and not look stupid when I challenge them.

 

At a glance, it looks ok to me, a bit OTT if anything - belt, braces and piece of string.

The only thing you don't mention is the span, and the exact spec of the truss - pretty easy to check out. (And unless its a long span or a super-flimsy decorative truss, a handful of parcans is not going to be overloading it.)

 

If you think its safe, what are you going to challenge them about? Maybe I'm just misunderstanding you. Why not just ask your contractor to talk you through their design?

[Jambo_UK]

The span is 3m made up of two 1.5m sections.

 

As for the challenging thing I was only going to do it if I could find a fault after getting advice. They did talk me through it I just wanted to did it double checked it.

 

Here is a photo of what they look like...

 

http://www.hdlma.co.uk/forum/download/file.php?id=65

[richard]

Assuming that you have checked that the suppliers are competent to do the task, have the relevant insurance, RAs and MSs then you don't need to worry too much about their precise methods - you pay them for their experience and skills, not to check their every move - obviously if you thought they were doing something unsafe then you should start to be worried..

 

However, this is assuming you are paying the people, you don't say that you do - and I assume you do, however if you are not then it is worth bearing in mind that liability can be shifted somewhat as you don't have any form of official contract for the services.

 

As I say, if you have copies of all the relevant paperwork (and have checked that they don't say anything along the lines of 'client's responsibility to ensure...' then you should be OK

[Jambo_UK]

They are paid and they have provided me with Risk Assessments (RAs) but not a MSs. I'm assuming you mean a method Statement? by MSs. But I will double check the contract stuff tomorrow when I go to the centre.

 

As for their insurance they appear to be covered like another contractor I have worked with in Theatre and Events industry will have to check if they can rig temp overheads tomorrow and their PLI covers them for it. Should be a fun phone call.

 

Thanks for all the advice, That's my biggest worry nearly sorted.

[tokm]

Two things that spring to mind..

 

First thing... That 'truss' isn't in shape or form, 'proper truss'. I very much doubt it'll have any sort of official rating or a sheet of loading specifications. It's basically cheap DJ cack. I'd suggest you get that looked at.

 

Second thought... 16x par64s.. I'd be interested to see how you'd rig that many on there. 3m isn't really enough space and I'd even hazard a guess that putting that many cans on would overload it a fair bit. Their only intended for 6 or 8 smallish DJ effects..

 

Seems like you've got the rigging facilities all sorted, just need to sort what your hanging off this RSJ... Personally Id go for some cheap (off eBay perhaps) tri-lite & increase the length of the span to say 4m..

 

HTH,

 

Tom

[Seano]

First thing... That 'truss' isn't in shape or form, 'proper truss'. I very much doubt it'll have any sort of official rating or a sheet of loading specifications.

What makes you say that? Is it not possible for a 'proper truss' to have only two chords? Hmm..

 

Second thought... 16x par64s.. I'd be interested to see how you'd rig that many on there. 3m isn't really enough space and I'd even hazard a guess that putting that many cans on would overload it a fair bit. Their only intended for 6 or 8 smallish DJ effects..

Look again. Its 8 pars - the mighty 16 par rig mentioned is a planned future expansion.

You think 12kg over a 1.5m span is likely to overload the truss "a fair bit"? Hmmm...

 

Personally Id go for some cheap (off eBay perhaps) tri-lite & increase the length of the span to say 4m..

So, having dismissed the existing truss as unusable on the basis of um... what was it again? You're now saying that buying second hand kit with an unknown provenance via fleabay is a good way to address that? Hmmmm...

 

:D

[Jambo_UK]

Not sure what the truss is all I know is it is silver. It may be Global Truss as they are big thomann buyers.

 

Just out of interesting how does their design differ from making this a permanent rig. As I have always been taught that rigging must be steel to steel. What would need to be changed to permanently fix it?

 

Disclaimer: I'm not thinking of doing it as the venue should have the funding to get the pros in later on to do it for them, it's just out of interest.

 

Cheers again for all the help.

[Neil Hampson]

First thing... That 'truss' isn't in shape or form, 'proper truss'. I very much doubt it'll have any sort of official rating or a sheet of loading specifications.

What makes you say that? Is it not possible for a 'proper truss' to have only two chords? Hmm..

:D

 

I agree over the questionable truss rating, the truss shown in the picture linked in one of the above posts looks very much like the stuff you get for DJ work, usually made from either very thin tube or often just plastic, it would probably struggle to hold the 8 PAR 64's, however in the original post 'Bi-lite' truss (Optikinetics, same as the original 'Trilite, but in ladder form) is mentioned, which would easily be up to the task of a few PARS, although I am always worried about joints in a ladder section as there is very little to stop the bending moment at the joint, something you won't get with Triangular truss, or even a single length, I would ask that the ladder is supplied in a single 3m section, not 2, 1.5mtrs. if there is any doubt over the truss, ask for the load calculation sheets, the cheap DJ stuff won't have any.

[Jambo_UK]

ask for the load calculation sheets, the cheap DJ stuff won't have any.

 

I got that paperwork through today it is Global Truss and was given the Loading sheet for the make of trussing which puts it at somthign like 60kg/m spread over quarters. So a 12kg lift shoudln't be a problem.

[Wuddy]

I can't believe where this thread is coming from or going to.

 

You the OP are employing some experienced riggers for a temp rig and understandably you want it to be safe.

 

But what's this coming onto the Blue Room seeking knowledge and experience, which you obviously don't have, in order to trip them up or play a game of one-up-man ship.

 

Providing an incomplete drawing and a photo which appears to come from a manufacturers catalogue you ask whether there are errors in the design with which you can confront the riggers, you even seem amused by the prospect of a phone call to enquire after their MSs and to query their ability to rig temp structures, why?

 

Personally I shouldn't want to comment on the suitability of the rig from the information provided neither would I want to critisise another professionals work via a third party -you.

 

Also, if you hadn't noticed, your truss started off as,

 

>SNIP<

Basically if is two pieces of bi-lite trussing

>SNIP<

 

Then the you forgot what it was.

 

Not sure what the truss is all I know is it is silver. >SNIP<

 

And then it was,

 

I got that paperwork through today it is Global Truss >SNIP<

 

Also if the riggers were experienced enough to supply you with RAs, insurance details, drawings, SWLs of steels and shackles, it seems to me to be rather remis that they didn't provide specs of the truss at the same time.

 

I do hope this team of experienced riggers aren't Blue Room members and reading your posts, for if I were the riggers I would politely tell you where to stick your job.

[tokm]

So, having dismissed the existing truss as unusable on the basis of um... what was it again? You're now saying that buying second hand kit with an unknown provenance via fleabay is a good way to address that? Hmmmm...

Well I was rather tired when I made that post, but the general idea was that the OP would be better off purchasing something/anything else. Ok, he might only be putting 8 cans on it now, but I can't see any mention of upgrading the truss when he wants to add more, so better to buy something suitable from the start.

 

What makes you say that? Is it not possible for a 'proper truss' to have only two chords? Hmm..

Nothing to do with it only having two cords.. By 'proper' truss, I meant something from a recognised brand other than 'generic', where you don't have any information on its load capacity, build quality and if its even suitable to be hung.. Remember, these things are designed to be clipped onto stands at either end. Basically what I said in my original post...

 

Just looking at the picture again.. are you sure its a picture of the truss you've got the specs of... That's a picture of some low rating clip together DJ gear you get from places like terralec.. not something I'd have thought made by Global truss and well.. its not silver! If you'd have linked to a picture like this >> Linky, then non of the comments I made would have been said, because, well.. That is 'proper truss' not low capacity/no real info available, DJ cack.

 

*edit - spelling and just noticed Wuddy's post.. not sure why I didn't see it before :P. Seems like the OP needs to get his facts straight*

[Seano]

I can't believe where this thread is coming from or going to.

<snip>

I do hope this team of experienced riggers aren't Blue Room members and reading your posts, for if I were the riggers I would politely tell you where to stick your job.

 

Heh, bit harsh. I just put it down to the OP being a bit overwhelmed by a new responsibility and freaking out a bit, but maybe you're onto something.

 

I wouldn't describe this as a 'rigging' job anyway, more a very straightforward small-scale lighting install. In the installers' place I'd be pretty irritated too, but they're probably used to it. If its been a real hassle for them reassuring their client, I'm sure their next quote will reflect that. :P

[Jivemaster]

As a manager bringing in specialsts you DO have a responsibility to ensure that they are competent to do the job. You can contract out the execution of a task but NOT the ultimate responsibiity for it. However usually there isn't a lot to do! a brief look at designs and RA and some corporate history should suffice rather than givung the people the Spanish Inquisition.

[Jambo_UK]

This is another issue different from the original but does concern the items used.

 

Both of the items I gave links before were used for the temp install but after going on the Stage Electrics Stage Rigging and Flying course, I'm now again unsure about the selection of hardware.

 

http://cpc.farnell.com/jsp/search/productd...jsp?sku=ST00897

http://cpc.farnell.com/jsp/search/productd...jsp?sku=ST00914

 

 

Both the Steel and the Shackle don't have a SWL rating on them nor do they carry an EU Kitemark, or the CE. Can these still be used for rigging or is it better to get ones that do have these information on them. I know the parts are fit for purpose but from my understanding of the course if they don't carry the correct information on them they shouldn't be used for UK entertainment rigging?

 

Or is this again down to appropriate planning and risk assessments to be able to use them safely?

 

Thanks for the help