Let's start out with your building dimensions. Also: when you say spanning 40' that seems a little wide for most wooden trusses. Finally, the load you would be putting on a 4" beam between trusses spaced ?? apart is not going to be 2 tons, so tell us the details of what you've got and what you want. Finally, you said "existing truss" so is this building already up? Do you have any zoning height restrictions limiting your ceiling height? There are many ways to limit the depth of crane trolleys on their bridge or beam.
I don't have building dimensions because I'm not putting up a building.
The 40' I referred to was a beam length. That beam would be perpendicular to the wooden trusses. It could be a 40 foot long building that is 12 feet wide. Or 30 feet wide. The trusses would span the smaller dimension. You could have a 1000 foot trolley beam in a 10 foot wide building.
When I said "existing truss" I was responding to ddurett896, stating that if you want to freespan 40' under existing trusses and hold 1 or 2 tons you're gonna need a ******' huge piece of steel to do that, and you're gonna lose that headroom under the existing trusses. If you had trusses designed to support a beam, then the beam could be much, much shorter, since it'd be supported every 24 or 16 inches.
Did you even read this thread? Am I being trolled?
There's tons and tons of posts about someone wanting to hang **** from their conventional "homeowner" type wooden trusses and there's always people responding that the trusses are not designed for that. And they're correct.
I want to see what the correct, engineered way of hanging a trolley beam on common trusses looks like, and I'm asking why I can't find any examples of common, conventional wood/gang nail trusses that were built to hold a roof up and a trolley beam too (except for tamry's post).
This is a theoretical discussion. I'm not building anything, I just like the conversation and the chance to learn and better understand how **** works.
I very much doubt that it's not done because it's cost prohibitive. People pay dumb money for stuff all the time.
I very much doubt that "it's been done, but nobody took pictures". It's 2025. If something's been done, there's pics online of it. This subforum is for people to show off their junk.
I know that it's not impossible, because nothing is impossible; I'm not an engineer, but I know for sure that if I take some conventional trusses and fully sheath them on both sides with 3/4" plywood, and put them on strong enough walls then I can use those trusses to hold up a little trolley beam that I can lift things with.
Is it something that's not common? Well obviously yes, since I can't find examples of it online...
