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I am investigating the possibilities for hanging a banner or set of banners on the side of a railroad bridge spanning 6 lanes of traffic on Highway 10 in Anoka. The only access to the side of the bridge would be from above or by closing off freeway lanes. The client wants to be able to change out the banners a couple of times per year and re-use the banners.
We have all seen those HUGE banners hung on the sides of buildings in the trade mags. But on a bridge? Anyone got any ideas for hardware and installation methods - or outsourcing same?
Not having tackled a project like this (yet), my initial reaction would be to suggest installing a couple of horizontal cables to the bridge and string a mesh banner between the cables using "D" rings and ratchet straps to secure the ends.
However, IMHO, this is definitely one of those projects that needs some sort of deposit before you start herding cats.
I'm sure it can be done - if the bridge can support the wind-load. But, it would take a lot of leg work to get the ball going, even before you get the order and start printing.
You or your client will need to start with the bridge owner to secure permission, get the engineering done to develop an installation method, determine the materials used, calculation of wind-loads, etc. In theory, the deposit would cover this expense because you can't work for free while doing the research, only to find out that it may not work.
Then comes the fun stuff The most common way that I've seen and read about for installing building wraps is a custom cable system that supports the banner on all sides. Then the banner is attached to the cables using "D" rings or rope.
Assuming it can be done, access will be difficult and you'll probably have to choose between shutting down the highway, the bridge or both for the initial installation. Future changing out the banner probably can be made easier with the right design and good planning.
Just for kicks and giggles, I would start by contacting one of the companies featured in the trade mags and see if you can pick their brains a little. Then develop a plan from there.
A couple of additional thoughts are can you get permission to stop traffic? If you use a mesh banner material (which is common in building wraps), will it look ok when installed?
Havin' fun,
Checkers
-------------------- a.k.a. Brian Born www.CheckersCustom.com Harrisburg, Pa Work Smart, Play Hard Posts: 3775 | From: Harrisburg, Pa. U.S.A. | Registered: Nov 1998
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The bridge belongs to the city, and their engineers will have the final say.
"The most common way that I've seen and read about for installing building wraps is a custom cable system that supports the banner on all sides. Then the banner is attached to the cables using "D" rings or rope."
Can you tell me a little more about this cable system and how the banner is attached?
-------------------- a.k.a. Brian Born www.CheckersCustom.com Harrisburg, Pa Work Smart, Play Hard Posts: 3775 | From: Harrisburg, Pa. U.S.A. | Registered: Nov 1998
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posted
I will not be hanging this(these) banners. We are just exploring possibilites at this time. I do hope to be able to sell them the banners though, when the time comes. And Checkers, 91 feet is too far to stretch with only the 2 ends supporting the length. Unless the cables on the top and bottom are HUGE and TAUT and mounted on steel brackets that are welded to the bridge on both ends, and have more cables to support - hm-m-m-m. We might have something here.
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Its exactly the same as an over-the-street setup.
You're probably looking at two 1/4 or 3/8 inch (or even 1/2 inch) "aircraft cables" (twisted wire cable) anchored to the bridge at both ends and a few places in the middle. The City's engineers will (should?) know what that needs.
What you need to tell them is the distance between the two cables. The distance is the height of the banner, plus an inch or two fo foot high banner, hemmed, is 45 or 46 inches, add 1.5 inches for the clips and you have 47.5 or 48 inch spacing on the cables. Your 16 oz banner will need to have reinforced hems (hem and tape all sewn together) with grommets every 2 feet top and bottom. You'll clip the banner onto the cable at every grommet with metal clips.
If they want to keep the banners up for more than a month each... maybe sheets of plywood or aluminum behind them... as a wall to block the wind.
the Fellers catalog used to show the details.
-------------------- :: Scooter Marriner :: :: Coyote Signs :: :: Oakland, CA :: :: still a beginner :: :: Posts: 1356 | From: Oakland (and San Francisco) | Registered: Mar 2001
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posted
oops, my example was for 48" banners. same approach for 96" banner, but you might need heavier material. I'd definately get some engineering... and it might really be best to bolt on plywood behind these things - that's a lot of potential wind load.
it comes down to how long this banner will be up, will be used every year (for the 4th of July festival or something) or changed out every 4 weeks?
It might even work out to treat it as a billboard -- paper billboard prints applied to plywood panels which are then fastened to the bridge with wingnuts or something.
-------------------- :: Scooter Marriner :: :: Coyote Signs :: :: Oakland, CA :: :: still a beginner :: :: Posts: 1356 | From: Oakland (and San Francisco) | Registered: Mar 2001
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