Windy Ribs

There has been a bit of a shift in my project since my last post, one that has necessitated some new thought towards the kinetic aspects.  By bringing the canopy membrane above the walkway/lookout the programatic relevance of this intervention is greatly enhanced.  Suddenly this structure becomes a vantage point to appreciate the worst (and still the best) weather that this beach has to offer.  The wind driven rotation of the ribs around the walkway and their effect on the protection the membrane offers from the elements above would certainly add to the drama one witnesses during a powerful storm.

There are essentially two elements to the steel aspect of my intervention.  There is the cantilevered walkway/lookout structure and the ribs that bisect it, supporting the membrane (the distal ends of which are connected to the rocky edge of the beach).  There are two varieties of ribs: static ribs which form the rigid connections for the membrane points, and active ribs which, by way of their canvas wind catchers, rotate with the wind, activating the membrane between the fixed points.

Given the fact that I've had to redesign the steel ribs I've posted up the newest versions below, following the plan that shows the static - active - static rib pattern.

Active points in blue between the fixed points
Note the actual shape of the walkway in plan is not yet final... 

Static rib.  Note the canvas "sail" is seen here in the section because it is continuous, linking all the active ribs.

This is an example of an active rib, one that pulls the membrane down as the wind pushes on the canvas "sail."

This is an example of another active rib, the mechanics of which are slightly more complicated.  The dual pivot points allow the rib's movement to push the membrane upwards.  Note, I need spellcheck for my trace paper... sad.

The thing that I hope will really add to the interestingness of the kinetic aspect of this project is that I intend for each active rib to be different, acting on a different part of the membrane or in a different way.  They will all have a similar windward side because that is driven by the need to catch the wind in its predominant direction but their mechanics and resultant motions will hopefully all be different (there are likely to be 7-10 active ribs, that shouldn't be too difficult.

Next up, model a rough version of all of this to post before Monday.  Also, I've got to start playing with using Grasshopper to approximate the motions that the ribs (and therefore the membrane) will go through during a storm.  Using that model (or maybe manually without it) I'll create a series of images showing range of motion in the style of (insert the name of the old school photographer who took pictures of naked people jumping).

J