I've been working with a P.E. on design of a rooftop, 70 foot guyed Rohn
45G tower for an academic building. I specified use of 4130 chrome moly
tubing mast material, but he informed me that TIA-222-G doesn't list
this particular steel as an allowable material, and heavy wall aluminum
tube is prohibited. He specified instead ASTM A53 Gr. B steel pipe for
the mast material, which has a much lower yield stress (35 ksi
minimum). After searching the TowerTalk archives for discussions on
mast materials, I'm wondering why 4130 chrome moly steel tubing with its
much higher yield stress doesn't make the list of allowed materials
under TIA-222-G?
Any insights?
Thanks!
Mike, K8CN
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|