Lightweight Tower Construction - lattice towers and guying

[Windy_Skies]

A topic about guying.

A topic about lightweight tower construction.

@PierreB

Guy cables are problematic: they are ugly, take up space…

@ChristophePochari1

A classic way to increase the lateral stiffness of a tower is by fastening guy cables to transfer the lateral bending moment into vertical compression. Unfortunately, such a scheme does not increase the load capacity of a slender-column tower, since it simply discretizes the compression forces between the guy-cable mounting points. Guy cables therefore only impart an improvement in the stiffness of the tower, but they do not increase the load capacity, they are not in themselves a source of strength. A wind turbine is heavy and generates strong torsional loads, which cannot be born by a thin-wall tubular or lattice tower, regardless of whether it is laterally stabilized by guy cables. In order for an ultra-tall tower to work for a wind turbine, it must be very stiff and able to carry tens of tons of both static dead-weight and occasional gust loads which generate strong bending and subsequent compressive forces.

@tallakt

You could maybe try to figure out if the tower height is limited by not having guying or maybe there are other reasons why current windmills are not higher.

@dougselsam

Anyway, I was trying to imagine why they ever stopped using guy wires at utility scale for wind turbine towers. I’ve come up with a few:

1. Safety - trucks and cranes are driving around all the time. Do they want to hit a guy wire and bring down a turbine?
2. Sabotage: Anyone with a wrench can undo a bolt and bring the whole thing down in a minute. Or a cutting torch… Or bolt cutters…
3. Visual appearance: Windfarms suffer from visual clutter as it is - guy wires might be seen as more clutter. A big part of getting projects approved is making nearby residents and even passersby happy with the appearance. Tubular towers have a cleaner look than lattice or probably guyed tubular towers.

It’s a strange take I think to discount guying. The whole point of AWE is to increase the members in tension and to decrease the length of cantilevers.

Suspension bridges and other structures using cables would have the same drawbacks that guyed wind turbine towers would have. The problems don’t seem to actually exist or matter much though.

[Windy_Skies]

@tallakt

You could maybe try to figure out if the tower height is limited by not having guying or maybe there are other reasons why current windmills are not higher.

You’d need 5-6 times as much steel as you need for a typical height wind turbine tower, using the standard design, to make it twice as tall: https://youtu.be/Jk02_MzyLBI?t=534 (turn on cc and auto-translate). If you build it like the Eiffel tower, you only need 3 times as much.

[PierreB]

@Windy_Skies

https://youtu.be/Jk02_MzyLBI?t=534 (turn on cc and auto-translate). If you build it like the Eiffel tower, you only need 3 times as much.

The measurement lattice mast is 300 m high, and only 1.20 m wide (as specified in the text and at 0: 30), thanks to the guy wires.

The planned wind turbine on a 300 m high lattice tower (9: 20) does not appear to be guyed. However, the base is very wide.

As well as saving a lot of weight, the lattice structure offers much less resistance to the wind blowing through it, as explained at 9:27.

[Windy_Skies]

@Windy_Skies

This reminds me a bit of space nets (Conrad Roland) Video testing forces: HowNOTtoHIGHLINE

Conrad Roland

[Rodread]

I really like the idea of using space net style architecture for AWES
From the company website

Spacenets™ climbing pyramid playground | KOMPAN

to suspend light generation devices in tensile hexagonal cells between valley walls…
I made a design sketch a few months back

[dougselsam]

Hello Roddy:
I think I was maybe 20 years ahead of you on that.
I posted this pic from circa year 2000, a couple weeks ago but now I can’t find it - probably moved to some new “topic” or just deleted for its potentially factual, or at least helpful, content…

[Windy_Skies]

@Rodread

hexagonal cells

Hexagons are kind of like the inverse of triangles I think. If bubbles made a regular shape in a plane, they would make a honeycomb pattern. To connect the bubbles, or balloons, together you would use a net made out of triangles. Here your AWESs would be the round bubbles that sit inside the larger hexagon clearing made by the triangular net. The net would be the icosahedron, the AWESs the truncated icosahedron.

Valleys I don’t know, not everywhere has valleys, but nets and towers working together is at least interesting I think.