Jun 27, 2015 - 08:39 AM
The guidelines for tower construction actually come from an ANSI standard, ANSI/TIA-222-Rev G, which is available for purchase for around $800-$900.
However, here are some websites containing excellent information, you can peruse and see if they provide additional specific information that is helpful to you or see if they spark new questions.
The website above outlines the standard, the timeline of changes and what the upcoming changes will be. It is very general information, yet accurate.
The above website, is a very detailed report written by David Davies, a Director at Electronics & Research, Inc, a company that manufactures and engineers tall towers, antennas and transmission line. Their home site iswww.erinc.com.
SITA has reviewed numerous municipal codes and has seen a variety of setbacks or fall zones for towers, ranging from no fall zone, to a fall zone equal to 200% of the height of the tower. In my 14 years of tower experience I have seen several tower up to 500' deconstructed by cutting them down and there is no clear cut pattern. If a truck accidentally hits the anchor of a guyed tower there is no guarantee the tower will collapse in an organized, pre-determined fashion. Yet with that said, the #1 cause of tower failures in the above referenced document, from David Davies, is tower construction.
Below are links to 3 Youtube videos that show towers being "dropped" in a controlled fashion, via different methods and you can see they all fall slightly differently.
Please excuse the quality of the videos and any verbal content, these are shared with me through an industry friend and are not part of SITA or our website and have not been edited or altered.