I would like to build a suspended railway system in my large basement. The systems available from dealers are VERY expensive (example $24 per foot!). Has anyone built a homemade system? I am going to attempt one and have some ideas, but am a curious to see if anyone has already attempted/built a system. I have an outdoor G scale railroad and an indoor HO layout. The suspended system, if developed, would be used for the G scale trains.
You could also use Unistrut and all-thread. I use that stuff a lot for bulding pathway and structured support systems for cabling, and it should work very well for the application you are speaking of. It would be fully adjustable from the bottom. I think most of what you need you could get from The Home Depot, but you would get better pricing at a Fastenall or similar supplier.
I have even thought about using it myself for a "hanging" layout.