I know you guys warned me about the size of the banner I was Making(4' x 25') but I had already ordered it so I had to go ahead and use it.I gave the banner to the local C of C and they had it mounted.I could see that the way they mounted it wasn't normal. After a couple days of heavy winds coming up the lake the banner was on the ground with one top corner ripped out,the bottom strap ripped off,and a broken pulley that they used on one side. I won't go into all the Gory details of the wacky mounting system but I need to Give the town a good explanation on how to properly mount the next banner (the same size) that they want,they also want the last banner repaired for next year. Has anyone ever tried using a cable system on top with a weighted bottom so that the banner can lift and let the air spill out? This banner is being mounted between two wooden phone poles about 45' apart.Even though it sounds like a really big banner it looks almost small when it's 24' up over the road,so I really don't want to tell the C of C they can't use the new $500 banner that they only used once.Thanks for any input!
Posted by Wayne Webb (Member # 1124) on :
I think a wind gust of only 35mph can exert a force of about 8lbs per square foot. If that is so, then a banner of that size is recieving a total force of 800lbs. Imagine suspending the banner from its four corners like a hammock and piling on 800lbs of sandbags. ON top of that, there is alot of snatching and jerking going on.
Bungee cords will absorb most of that sudden shock.
Posted by Doug Allan (Member # 2247) on :
the main difference between what many people try & what should be done is... Don't yank one corner this way with one rope... & yank the other corner that way with another rope... then all the stress and strain of the banners own weight, any wind resistance & all the other combined forces defined by fancy physics computations focus directly on the corner of the banner... resulting in.. well, I don't need to tell you that.
Tell them to use the straight cable (or good rope.. or both) from pole to pole, & use knots (or screwed on cable ties) to secure the corners where the banner can't bunch up... but it has just a little play so in a rope situation, the rope can & will stretch, but the banner won't be trying to.
I never heard of using weights at the bottom... I would secure the bottom the same way as the top/
You may want to cut half moons to spill out some air.
Posted by Bill Lynch (Member # 3815) on :
The city here has a good set-up. A taut steel cable on top. They zip tie the banner on top. The bottom two corners are bungeed to screw eyes. They have a spec sheet for all vendors to follow. (And yes, they require wind slits) This works pretty well. Still lose a banner now and then, but that's to be expected.
Posted by John Lennig (Member # 2455) on :
Oh ya, that snatching and jerking will get ya Everytime!!and i've got the medical bills to prove it!
