[EM3]

Well I have never taken out a center support but I did help add a still beam and side support poles in a 2 car garage. You could paint them black so they wouldn't be noticible when the lights went out. My father in law had the supports and got the 24ft beam 2nd hand. He used a blowtorch to cut it to length and put bolt holes in it because he used two thinner beams instead of one larger one. It was real hard getting it in place. It required brute strength and a lot of planning. The supports are fastened directly into the concrete floor.

I can't figure out the 16 ft wide support but I'm not an architect. We just used the beam for support and columns to support the beam thus transfering the weight directly to the concrete floor. I'll reread your post later and if it makes more sense to me.