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Ignoring how completely illogical and counter to the main benefit of using a hovercraft this question is for a second...
Given the bridge is now closed until the new year due to concerns of further damage by heavy traffic. I was wondering how much force a hovercraft would exert on the bridge deck, given it's sitting on a cushion of air. Obviously air pressure will be exerted on the carriageway in order to provide lift, but how would that compare to the load exerted by a vehicle of similar weight?
If you drive a hovercraft halfway across, then switch it off, how does the load on the bridge deck change?
I assume this is fairly well understood by boffins out there. Would the dodgy bridge deck be effectively 'insulated' from the load, or would the difference/benefit be negligible.
Equasions/ridicule welcomed. 🙂
Exactly the same
but distributed evenly
The cushion of air must exert the same amount of force to the road as the mass of the hovercraft in order for it to hover?
forget hovercraft - hoverboards are what you need here
Force would be the same. Pressure would be much lower
The weight of the vehicle is still being borne by the structure of the bridge. However, there might be less "damage" as the weight is spread evenly rather than being carried by 2 or 3 axles. Also, as wheeled vehicles cross the bridge they are crossing various joins and other changes in road surface, causing more vibration. A hovercraft wouldn't do this.
The same load, just spread evenly across it's footprint, rather than as smaller high pressure loads at the tyre contact patches. So easier on the road surface but just as hard on the structure when static. Any vibrational/resonant loading will be much less or much lower in frequency.
Also, and part of this discussion, would be whether or not said hovercraft could easily make it up the bridge as it isn't flat - has some curvature to it. Not sure at how good they are at going uphill? Just a question of thrust I guess.
What about if the hovercraft was on a conveyor belt?
Have you ever been near a full size hovercraft going full tilt? I'd imagine quite a lot of vibration would be transmitted. Y'know, as noise... Frequency may be a bit different, I suppose...vibration. A hovercraft wouldn't do this.
I think you would still be beter looking at a water based solution.
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Some interesting photos [url= https://twitter.com/forthroadbridge ]here[/url] if you've not seen them.
Looks like they've been stripping that area ready to paint it..... makes you wonder how long its been broken for!
Although it doesn't look like those links hold the bridge up - it looks like they keep the suspended deck in register with the tower.
Why not just send the hovercraft over the water?
Why not just send the hovercraft over the water?
don't be daft
fasthaggis - MemberI think you would still be beter looking at a water based solution.
Maybe some sort of hovercraft?
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thinking back to school physics this definitely can be answered by an elephant in stiletto heels.
or something.
If you wanted to make it heavier you'd have to fill it full of eels.
Hovercraft can go uphill relatively easily.
The one that runs at the bottom of the road from my office has an incline to go up at either end.
Not sure I'd want to be in a Hovercraft going over the bridge with a nice sidewind going on though.....
what about a ground effect vehicle going across the bridge into a headwind?
I was wondering how much force a hovercraft would exert on the bridge deck, given it's sitting on a cushion of air
What's the cushion of air sitting on?
As above - the same, of course, given the hovercraft is not flying.
Speaking of hovercrafts, they really should get one of those old channel crossing ones and put it into service direct between Cardiff and Bristol.
Afternoon. I have a crate of canaries, that I'd like vorlich to take on his hovercraft over the bridge. And the possibility of a conveyor belt if that is of use?
Who needs a bridge?
why cant they just allow cyclists and people who cant afford a bike to WALK accross.
Who needs a bridge?
Vorlich, what exactly did you get up to during your school years? Ever heard of that bloke Newton?
He's the apple guy right?
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that's not a Newton, that's an iPhone
IGMC...
that's not a Newton, that's an iPhone
I recon it's around 1-11/32 Newtons.