Friday, December 3, 2010

Soleri Bridge: The Arc of Parabolic Catenary Guys

One second exposure, cars disappearing into blurs of light in the street

At the Soleri Bridge and Plaza Project, they installed the cables from the buddy pylons, up to the main pylons, and out across the span of the bridge on Thursday, the day this shot was taken. 

The title of this post strikes to the heart of the question: do these cables describe parabolas, catenaries, the troubled lines of guy wires, or the uncertain path of the merely decorative wire? 

If they have a question and answer session at the dedication, I would propose a flash mob-esque series of questions: 
Yes, are these cables weight-bearing? 
I was wondering, do those wires hold up the bridge?
My question is this: those cables, are they structural in nature?
Me? Oh, me? OK, um, the wires, yes, are they holding it up or what?
Oh hai! Can has suspension?
Would you say the curve of those cables describes parabolas, catenaries, or just troubled lines?
Hey, my buddy and I have this bet. Dis goofball suggests that the force exerted is uniform with respect to the length of the cable and thus the shape is nearest a catenary, whilst I hold that they are acting as guy wires and thus any arc perceived is more a factor of stretching and thermal expansion. I think I'm right 'cause those look like strain insulators up in there. Comments?
Excuse me, I'm next. Hi, can you comment on the wires? How they fit into the overall picture, function-wise, I mean. OK, also aesthetically, for I feel there is a logic at work here that would be useful to review as a whole, so to speak.
Uh, dude. Like, susp--whoa.
هو جسر معلق؟ 
--ension, man? The wires, like--whoa. Check out the light.
Pardon me, yes? Could you sketch out the force vectors for the pylons, you know, to give us an idea about the purpose of those wires?
OK, just one more question? Hi, my name is John Romeo Alpha, from the world renowned Phoenix bicycle blog, One Speed: Go!, and my question, as you might have guessed, is related to the cables which were put up just over a week ago [the dedication will be on Dec. 11]. Since the bridge deck and pylons have been in place for weeks, OK since September 30 for the main pylons, and since July 26 for the bridge deck or span itself, not that I've been obsessively keeping watch/taking pictures/blogging about it or anything, it's apparent the cables are not necessary for supporting the structure itself. Yet, mulling over it for, let's admit it, weeks or so, on and off, I'm not really prepared to assert strongly a simply aesthetic purpose or function (if you will) for the cables, although I would accept such an assertion as quite plausible and logical if made by a person in authority. I guess my question is, could you set the record straight, please, while also easing my clearly troubled mind, and understanding that deep down inside I have a secret and undying affection for parabolas: is this a Suspension Bridge Shaped Object?

It's almost done. To ride, to walk, to rest, to contemplate, to walk across hand-in-hand with the one (or four) you love. I heard there might be bells. Get up. Go ride.


Where do they go, what do they do


  1. Horizontal asymtotes.
    They only appear to be attached to the span.

  2. The more I look at the bottom image, the more I feel like them cables need to be thicker.
    Or something.
    Maybe they are just there in case of high winds or for Christmas lights.
    You should go over there and tug on them a bit and give us a full report.


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