NE/IA Wireless Association Seminar Covers Addendum to Rev. G
The Addendum 2 update of the Telecommunications Industry Association’s TIA-222-G tower structure standard, known as Rev. G, has been published and is available to the public, Carlo Franceschino, P.Eng., told an audience at a Nebraska-Iowa Wireless Association seminar, held Jan. 26 in Ankeny, Iowa.

In a seminar called “The Wireless Industry’s Path to Rev. G,” Franceschino, the special projects engineer for Sabre Towers & Poles, discussed how the new standard would impact the design and deployment of cell towers. The standard essentially was changed to keep up with advances in engineering theory and to be in alignment with international standards.

“The biggest change between Addendum 2 and Addendum 1 is an increase monopole shell resistance. We are looking at tapered multi-sided poles; you will now get a significant increase in the resistance or capacity of the structure compared with Addendum 1,” Franceschino said. “The other big change is requirements for existing structures.”

Franceschino went on to say that an addendum to Rev G was needed to be a part of the International Building Code. Additionally, the American National Standards Institute requires a review of the standard every five years.

Addendum 2 includes a new wind map and a map to help with designing for ice-loading requirements. The biggest impact of the new standard, Franceschino said, is replacing allowable stress design with load and resistance factor design (LRFD).

“The new way, LRFD, has been used international for some time,” he said. “What we are trying to do with LRFD is get a more accurate picture of the loads and the resistances of the structure and capture the uncertainty where the uncertainty actually lies.”

The revised wind map in Rev. G relies on 3-second wind gust speeds, which are used by the IBC standard. Rev. F uses fastest-mile wind speeds, which are no longer measured.

“For the Rev. G to be implemented by IBC, we had to adopt the 3-second wind gust speeds,” he said.

TIA-222-G-2 was formulated under the TIA Engineering Committee TR-14 Point-to-Point Communications System's TR-14.7 Structural Standards for Steel Antenna Towers and Antenna Supporting Structures Subcommittee.