I am curious to know if the St. Louis Gateway Arch would be strong enough to act as a support structure for a giant vertical axis wind turbine.

I way I am envisioning this being constructed is that a radial shaft bearing block could be installed just below the top of the Arch and a combined radial & thrust bearing block could be constructed down at ground level. 600 feet of steel piping would be installed between the top bearing block and the ground level bearing block. The turbine blades would be attached to this steel piping and the rotating steel piping could be connected to an electric generator on the ground via some sort of pulley and chain setup.

Could the St. Louis Gateway Arch be used as a support structure for a giant vertical axis wind turbine?


Here is a drawing of what a vertical axis wind turbine might look like positioned underneath the Arch:

enter image description here

  • 3
    $\begingroup$ Who would consider blocking the view? Is this a beer based question? $\endgroup$
    – Solar Mike
    Sep 19 '21 at 5:52
  • $\begingroup$ No. You would be introducing dynamic loads at the most critical point of the structure. $\endgroup$ Sep 19 '21 at 14:23
  • $\begingroup$ @SolarMike, no, I'm simply wondering if the Arch would be structurally strong enough to support a VAWT of this size. I like the Arch just the way it is and I wouldn't want anything added to it like a VAWT. $\endgroup$
    – user57467
    Sep 19 '21 at 15:13
  • $\begingroup$ Most VAWT I have seen, locate the top bearing by cables, usually 4. $\endgroup$
    – Solar Mike
    Sep 19 '21 at 15:14

The arch has been designed to resist wind loads but just the wind load its 630 feet arch can cause.

The motto of not over designing the structure to reduce the weight of the structure to a manageable weight has lead to even reducing the viewing openings on top to 7 by 27 inches.

Over 500 tons of pressure was used to jack the legs of the Arch apart for the last four-foot piece to be inserted at the top. A larger window would not withstand that pressure. from park official guide.

Adding a huge vertical windmill between the base of the arch and its top will impart lateral loads by orders of magnitude above what the arch is been designed for and cause a catastrophic collapse.

It also will destroy the grace and beauty of the arch that has been designed with a sense of drama and poetry to reflect the river and moonlight.


There are a lot of assumption in this answer.

I assume that the structure is not overengineered (although monuments tend to be). That means that the arch has to withstand its own weight, shear forces and bending moments from the wind and snow and earthquakes.

Based on the above assumption (and the additional updated) the addition of the giant vertical axis would add significant aerodynamic drag loads.

Then there are following problems

  • when the direction of the wind is transverse to the image, then there are bending moments off axis along the weak axis of the moment of inertia, AND twisting moments.
  • when the direction of the wind is parallel to the image then, although the bending moment is parallel to the axis of the arch and there is no significant twisting moment, the arch interferes with the wind and reduces the performance.

So in the extreme two cases of the wind direction, either there are some significant loads, or there is significant reduction of the performance.

Additionally, monuments - like the Gateway Arch - would lose their identity and symbolism if you add another structure on top of them.

  • 3
    $\begingroup$ Think the OP want the turbine inside the arch, not on top. $\endgroup$
    – Solar Mike
    Sep 19 '21 at 6:31
  • $\begingroup$ @solarmike that was not my interpretation, but I may be wrong. I would have drawn a quick drawing to make it more clear but I am currently away from a desktop. $\endgroup$
    – NMech
    Sep 19 '21 at 6:40
  • 2
    $\begingroup$ "bearing block just below the top of the arch" and "a combined radial & thrust bearing block at ground level" … $\endgroup$
    – Solar Mike
    Sep 19 '21 at 6:49
  • $\begingroup$ @SolarMike, yes, the turbine would be positioned inside of the Arch. I will add a drawing of how a giant vertical wind turbine located underneath the Arch might look like. $\endgroup$
    – user57467
    Sep 19 '21 at 12:31
  • $\begingroup$ @user57467 it is not me that needs telling, I got it from the start. $\endgroup$
    – Solar Mike
    Sep 19 '21 at 12:33

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