Tensegrity masts for radio towers? - Page 1
Forum section: electronics / rf-microwave

author: cdev
author_rank: Super Contributor
timestamp: April 05, 2022, 08:48:32 pm
content: A tensegrity mast was a development of the work of R. Buckminister Fuller, the inventor of the geodesic dome, My forum picture is of one.A tensegrity mast is also an inexpensive, strong tower that can be erected for radio uses, in theory, at least. However, as far as I know, nobody has done this.Why not?Seehttps://cimar.mae.ufl.edu/cimar/pages/thesis/knight_byron.pdfhttps://www.archdaily.com/893555/tensegrity-structures-what-they-are-and-what-they-can-be/5a663feef197cc48d7000059-tensegrity-structures-what-they-are-and-what-they-can-be-imageThere is another proposal for the Santiago antenna contest that I kind of like too. Non tensegrity. It incorporates a circular viewing platform suspended above the city. They say it is inspired bythe area's many active volcanoes.. whatever that means..These kids of sites are popular places for couples to kiss.https://www.designboom.com/architecture/proposal-for-torre-antena-santiago-by-architects-of-invention-02-16-2014/

author: El Rubio
author_rank: Regular Contributor
timestamp: April 07, 2022, 12:46:58 pm
content: Doesn’t look inexpensive at all to me. I didn’t read the doc’s, but looked at the pics. It doesn’t seem very practical or as simple to design and fabricate as common monopoles and guyed towers.

author: cdev
author_rank: Super Contributor
timestamp: April 07, 2022, 01:20:35 pm
content: Ask Santiago, Chile!Its just made of pipes and cable. And its exceptionally strong. A very long time ago I participated with friends in building one. It was fairly easy and didn't take long and went very high up. It used regular steel pipe and steel cable. I forget the exact specifics except that it went up very rapidly and used common parts, and was cheap.I want to look into it again!Lots of height for very little effort. and modest cost as one can use off the shelf components. The base can be a square of concrete, and two steel pipes to start it.

author: Fladave
author_rank: Newbie
timestamp: April 07, 2022, 02:28:27 pm
content: Theres a guy on Youtube that demonstrated one, a three legged tower about 30 ft or so. I believe it was a surplus find and a prototype of a military product. If I can find it I will post the link.

author: cdev
author_rank: Super Contributor
timestamp: April 07, 2022, 03:31:34 pm
content: I would love to see that. As I said, building tensegrity structures is often simple and inexpensive. This is true of geodesic domes also. Thats why they became quite popular in the 60s and 70s. They enclosed a lot of space and cost little to build. I used to have a friend who lived with his wife and young son in one - it was quite nice and had a lot of pluses to it. It was in the redwoods in the Santa Cruz Mountains in central California. (Also, irrelevant) He also brewed his own beer and it was some of the best Ive ever tasted.The geodesic dome part made up the main central enclosed space of a modern, suburban 3 bedroom home. It was warm and solid looking. The main unusual aspect of the home was the lack of rectangularity. There were few if any right angles in that home. Other than that it was quite home-y. The kitchen was very large and ajoined the main family room, which made the home quite welcoming and cooking friendly. It was kind of an open plan house but it did have three nice private bedrooms, and a full basement. It wasn't rustic in any way, except for being in a forested environment with big tall trees. (a second or third growth redwood forest (smaller trees than some I've seen, they sometimes can get huge.)The main room of my friend Edie's entire house was carved out of a single redwood stump that adjoined Arcata's "community forest". That was really something as the stump was still alive and growing many sprouts from it even as it was being used for a house. It always smelled fragrant and fresh! Thee was a stream right nearby and being in the redwoods, the forest floor was soft and springy.. fun to walk around.Ive never seen another house built like it. It was unique. It also had a compact, efficient wood burning stove in it it which kept it warm and toasty in the winter.

author: A.Z.
author_rank: Super Contributor
timestamp: April 07, 2022, 03:43:09 pm
content: Quote from: El Rubio on April 07, 2022, 12:46:58 pmDon't know about the cost of such a thing nor about the ease of installation, but sincerely I wonder if such a "tower" will be able to support (say) a 3 elements HF yagi and its supporting pole and rotator if invested by a somewhat "robust" wind; the problem, as I see it, is that in such a case the load will be concentrated at the top

author: TimFox
author_rank: Super Contributor
timestamp: April 07, 2022, 03:43:52 pm
content: As I understand it, the practical problem with geodesic domes is sealing the polygons to each other on the edges to avoid leakage in rainy weather.That, obviously, is not a problem with the tensegrity mast design.

author: cdev
author_rank: Super Contributor
timestamp: April 07, 2022, 03:50:05 pm
content: Quote from: A.Z. on April 07, 2022, 03:43:09 pmI don't know how they work out for wind loading which I think is what you must be most worried about. Certainly there are vertical towers that load the wind less, I'd expect. Just a simple carbon fiber or fiberglass mast might be better in that respect, I dont know how durable they would be. They might last a long time, especially if the antenna that was supported was constructed with a mind to minimizing the wind loading, maybe a spider beam antenna would be a good match to one? As I think you are pointing out the leverage of a large antenna on a long tower can put a substantial amount of lateral force on a tower. Thats what makes them fall when they do.What I do know about tensegrity masts is that compared to more conventional masts they are surprisingly strong and represent an efficient solution. A museum in Washington has a tensegrity mast there as an exhibit, it is quitetall and was remarkably easy to build, it is in essence a sort of proof of concept. If you scroll down you'll see a lot of images that I psted in as attachments. I have not seen a cost analysis but I suspect the cost is very low. One just needs pipe and cable to build one. The pipe just needs a single hole drilled in it. If the pipe is cut and sharp, the ends should be capped. The cost seems likely to be very low.Examples:

author: cdev
author_rank: Super Contributor
timestamp: April 08, 2022, 01:28:27 pm
content: Quote from: Fladave on April 07, 2022, 02:28:27 pmPlease do, I'll see if I can find it via Google to with what you shared. Tensegrity structures are often really useful in architecture.Bingo! Found it on first try. Is this it?https://www.tmastco.com"The Mast Company is now in its 26th year of providing cost effective antenna array support solutions to individual, commercial and military activities. Thousands of our aluminum mast sections and custom accessories are in use around the world.The Mast Company is a leading provider of portable rapidly-erected multi-purpose antenna array support structures for voice, video and data systems. We sell direct to amateur radio operators (hams), military personnel, military support organizations, internet service equipment providers, and local emergency communication groups. Some more unusual uses have included small sail boat masts/jibs, bat research netting supports, wind chimes, weather instrumentation towers, and aerial camera support.The Mast Company products are designed and engineered for portability, rapid deployment, versatility, and ruggedness. Instead of having a full-time engineering and design team working to develop new designs and new ways to perform simple tasks, we elected to work with existing surplus and commercial items to provide an innovative line of products to meet the demands of communication specialists. Additionally, our products are designed for minimal visual impact. Wherever possible, we use non-corrosive materials and hardware for long-term survivability in the tough environmental conditions so often encountered in the field. Our mast systems are strong, but light and compact enough to be stored in portable shelters/tents or carried in standard personal transportation vehicles.Because of our location in an area of the country with numerous nearby military installations, we are able to obtain materials at a cost reasonable enough to make this a viable part-time effort.Browseour web site, learn more about our products, and contact us for discussion of your application. Our recommendations are very conservative, so rest assured that we will not suggest questionable applications. And, if our products are not what you need, we will gladly provide recommendation to other suppliers."

author: cdev
author_rank: Super Contributor
timestamp: April 08, 2022, 01:55:09 pm
content: Quote from: Fladave on April 07, 2022, 02:28:27 pmI think I found it, and its not super expensive.http://tmastco.comThey also sell telescopic poles..https://www.tmastco.com/main/page_products_telescopic_poles.html