Trilite 200 triangular truss

[craiguss]

hi,im looking at building a box truss out of trilite 200 triangular trussing as I already own it!

the box truss would be 10meters X 5meters. there would also be a centre beam going the middle 5 meters long.

I was planning on using 3 1tonne chain blocks even distributed along both of the two 10 meter lengths.

what sort of SWL I could get from this sort of truss??

I wouldn’t be putting much on this truss, but I need to know the SWL before it can be arranged.

any help of information to getting this would be great!

[jonathanhill]

The loading charts for the 210 series are here:

 

http://www.optikinetics.com/technical-details/opti-trilite-210-straight-lengths

 

They were quite easy to find on the Opti website.

 

The usual caveats about 'a little knowledge is a dangerous thing, especially when putting metal in the air' and 'if you have to ask, should you be doing it' apply.

 

IMHO Tri-lite is unsuitable for the sort of thing that you are planning, unless you were using it for Rizla* storage.

 

*Other makes of cigarette papers are available.

[top-cat]

IMHO Tri-lite is unsuitable for the sort of thing that you are planning, unless you were using it for Rizla* storage.

 

*Other makes of cigarette papers are available.

 

IMHO that's a fairly unwarranted comment and based more on stereotyping than actual structural reasons.

 

As you say, the loading data is on Opti's website. If specs fit the application, use it! I have always been of the opinion that Trilite is useful stuff because of it's really low self weight.

 

Considering the compact size and low weight of modern lighting fixtures, if the OP was looking to hang a range of small LED movers and battens I'd think nothing wrong with it. There is just this reasonably unfounded stigma about Trilite that because it's very lightweight stuff you only have to blow on it and it will fall apart.

[trussmonkey]

while I don't like the truss in question the load tables read like this.

 

approx 5m span between hoists = 1245 lb or 565 KG UDL and a point load of 487 lbs (221 Kgs). This really isnt much at all.

 

what the tables don't give you is the max deflection for any given span. Deflection is an important thing to bear in mind and sometimes overlooked.

 

You really need to work out load distribution as well.

 

Unfortunately I have to repeat. If you cant work out a simple thing like SWL from load tables then you really aught to leave this to a rigger who can.

 

Caveat - OPINIONS IN THIS REPLY ARE THE OPINION OF THE AUTHOR BASED ON LIMITED INFORMATION PROVIDED. ANY RIGGING WORK MUST BE CARRIED OUT BY A QUALIFIED AND COMPETENT RIGGER. UNDER NO CIRCUMSTANCES AM I RECOMMENDING THE ORIGINAL POSTER TO FOLLOW ANYTHING WRITTEN ON AN OPEN FORUM WITHOUT SEEKING PROFESSIONAL ADVICE.

best

 

TM

[Seano]

Deflection is an important thing to bear in mind and sometimes overlooked.

 

The downside with Trilite is that deflection often has more to do with how sloppy the spigots are than it has to do with the actual deflection. ;)

[trussmonkey]

true.... I wasnt going to start a schpeel on it as it could turn in to a long one. :)

[paulears]

For the weight of the stuff I was quite impressed by the loading figures. It's easy for those working with the bigger varieties to see theses kinds of figures as 'low' when very often they're perhaps being used to replace runs of aluminium single tube. In this case the OP has a pile of bits, and I too view spigots as the problem. So much depends on the long sections. He mentions the ten metre length. If the shape being built is a rectangle turned into a figure 8 by the extra run down the middle, then if this is three 3m lengths then the right angle bend then suspension is at the joints so deflection not a problem. If the width is a hotchpotch of multiple units then it's droop at the joints, which isn't the same as real deflection.

 

I know we must be careful, but stadium rigging is not quite the same as this. I see far more installs of this kind of structure where the heaviest item is the truss, not what's on it. A few years ago I used some of this stuff in a bowling alley running across the space holding the scoring monitors and a few speakers. Load wise a very small proportion of the capacity.

 

We don't have enough information, that's clear. The OP could have provided a drawing showing the design and the components and he could have even shown what he was intending to hang. Then we could have given considered answers, without having to resort to doom and gloom. If we don't know, I hate it when we get forced into a danger will Robinson corner.

 

Members like truss monkey are idea to run these questions past, but only if they get the details. It's rather like going on a medical forum saying you feel ill and asking if you are going to die. A qualified doctor is the best kind of forum member for that question, but the only one who is never, ever going to say a categoric no!

[craiguss]

Hi guys, thanks for the advice,

I have had a rigger in to look and they have said it's easily possibleThey also tried to get us to use electric chain motors And we just don't have the money to do so, so I don't see why with my experience with rigging trusses I couldn't rig it once I have all the loadings.I just need a weight that the truss will take.

If you guys can tell me how to work it out I will be greatfull!

Once I get back I will let you know what the length of the pieces areI could work out the load but I didn't know what the loading is when you have multiple joins with spiggets??The biggest length of tri lite I have is 3mtrs so I may get away with a 9 meter spanSo that would give me three joins Along the long side of my figure of 8. 4.5 mtrs between hoists

 

I will be mainly hanging some small 250w fresnels And 4 robe led 136xt washes which weigh 18kg I think!

[david.elsbury]

Call an experienced and/or trained rigger. You have been given enough information above to work it out; if you still are unable to do so then I would seriously question your ability to do the job safely.

 

At the end of the day, if you can't afford to do it safely and correctly, and to be 100% confident it is ok, then you shouldn't be putting things above people's heads :)

 

David

[top-cat]

Call an experienced and/or trained rigger. You have been given enough information above to work it out; if you still are unable to do so then I would seriously question your ability to do the job safely.

 

At the end of the day, if you can't afford to do it safely and correctly, and to be 100% confident it is ok, then you shouldn't be doing it at all.

David

 

Post corrected, no charge this time. http://www.blue-room.org.uk/public/style_emoticons/default/cool.gif

[trussmonkey]

Craig this forum can only offer advice and I doubt you will find anyone willing to do the work for you on here. If you are as experienced in rigging trusses as you say you are you should by now be able to work out a simple thing like a load table. They are not difficult.

 

If you can not then seek paid professional help.

 

 

Paul - you are correct that stadium rigging is a lot different to what the OP is talking about but it still relies on the same principles (just with bigger numbers. But if you are rigging anything you should understand the maths behind it...

 

TM

[ImagineerTom]

...and you should also be able to work out /why/ they urged you to use electric hoists rather than manual ones and the impact this will have on your loading.