Truss across ST132's outside

Rafi Singer

Rafi Singer

Freshman
May 17, 2011
62
0
6
Waltham, MA
www.singerproduction.com
Pardon me if this belongs in lighting, but it seemed to straddle into rigging a bit.

What is the general line on safety regarding using ST132's for supporting 12" truss to hold lighting while under a stage's canopy? It's been suggested to me, however it didn't feel like the most stable/safe option. Is it something that could be safe with enough sandbags? Or is it better to suggest truss supports with bases/ST25's?
 
Re: Truss across ST132's outside

Concerns about wind loading aside, I'd start be figuring the weight of the truss, lighting, and cable. ST-132s are only rated for ~200 lbs, so you only get up to ~400lbs for your truss, cables, and fixtures. And that's assuming that the load is perfectly split between the 2 stands even during crank-up. In practice, you should derate the maximum static load to allow for slight imbalances and dynamic loading. I'd probably use something like 300lbs max static load, but that's a guess and not based on any calculation.

12" box truss weighs 4-6lbs/ft depending on vendor, so with a 30' span, you've already used up half your load capacity, even before you've added any fixtures.
 
Re: Truss across ST132's outside

Rob Timmerman said:
Concerns about wind loading aside, I'd start be figuring the weight of the truss, lighting, and cable. ST-132s are only rated for ~200 lbs, so you only get up to ~400lbs for your truss, cables, and fixtures. And that's assuming that the load is perfectly split between the 2 stands even during crank-up. In practice, you should derate the maximum static load to allow for slight imbalances and dynamic loading. I'd probably use something like 300lbs max static load, but that's a guess and not based on any calculation.

12" box truss weighs 4-6lbs/ft depending on vendor, so with a 30' span, you've already used up half your load capacity, even before you've added any fixtures.
Click to expand...
I'm a little late to the party here, but will chime in to what Rob said. I use ST-132s as speaker and lighting T-bar stands, but they don't have enough weight capacity to be useful for truss indoors or out. 12"x12"x10' truss weighs 60lbs per section. If you've only got 2 pieces of truss and you're using really lightweight fixtures - a few LED pars or something then you'll be OK, but for any reasonable amount of lighting, you're going to want a lot more. The Applied L-16 lifts or the largest Mobil-Tech lifts are much more appropriate - much more weight capacity, bigger leg span, etc.

Sandbags won't make ST-132s the right tool.
 
Re: Truss across ST132's outside

I've used the ST132s on stage for a back truss. They are okay with 24' of Global truss, a dozen flatpars and a couple of lightweight movers. That's as much as I would care to put on them and it was under a canopy, no weather issues. The heavier ST-180s or the models TJ mentioned would be preferable for a front lighting truss, or some of the VMB towers.
 
Re: Truss across ST132's outside

I own a few st132's and st180's and I agree with what's been said. As long as you're on solid, level ground and stay under the weight capacity spec'd by global, you should be perfectly fine. Make sure to raise the top mast first, followed by the lower. Also ensure that all weight is on the ring pins and not the winch cable under load, and that all the black knobs are twisted tight under load as well. I'd try to spec the light weight global spigot truss vs the applied/tomcat stuff to save a bit of weight capacity.
 
Re: Truss across ST132's outside

I've seen it done but I personally wouldn't use any stand like that outdoors in Massachusetts this time of year. Michael is spot on, though... you should be fine if you follow what he's written above. Mr. Pyle's evaluation of what you can do with them is what I'd probably suggest - I'd estimate no more than 2/3rds what they are rated for.

What purpose are these for?
 
Top Bottom