I suppose this is a dumb question, but it's something I've been curious
about for quite a while.

There's a stretch of Marine Drive in N. Vancouver right beneath a very
steep slope, almost a cliff. The ground is dirt, stabilized by shrubs
and trees. Right under it, along the side of the road is a chain link
fence -- with giant steel rings or hoops installed, something like
in this picture:

http://picasaweb.google.com/nancy.ro...45414931075842

What are these hoops all about?

Btw I'm fully aware that by its nature this kind of question is
a wide-open invitation for all kinds of fanciful explanations.

My best guess -- thinking on-line here, is that the rings are associated
with a slide hazard. That's the only context in which I've seen them.

So what good would they do? Obviously they can't stop a landslide.
Tons of dirt or rock coming down would be enough to first knock the
fence down and then bury it. Some time later a repair crew shows up
and finds a big pile of material on the road and perhaps one or two
fence post tips. There might even be some of these rings in view, but
what good do they do now? Perhaps there's a car trapped under the slide;
do they use the rings to hoist up the fence with a crane?

All replies appreciated, even authoritative-sounding but outright
fabrications.

Sean_Q_
'99 FLHTCUI / '04 S40 / '81 CB750 AMEN chopper / various derelicts

"Sean_Q_" <nospam@no.sapm> wrote in message
news:Ppkrk.101543$nD.16565@pd7urf1no...
>I suppose this is a dumb question, but it's something I've been curious
> about for quite a while.
>
> There's a stretch of Marine Drive in N. Vancouver right beneath a very
> steep slope, almost a cliff. The ground is dirt, stabilized by shrubs
> and trees. Right under it, along the side of the road is a chain link
> fence -- with giant steel rings or hoops installed, something like
> in this picture:
>
> http://picasaweb.google.com/nancy.ro...45414931075842
>
> What are these hoops all about?
>
> Btw I'm fully aware that by its nature this kind of question is
> a wide-open invitation for all kinds of fanciful explanations.
>
> My best guess -- thinking on-line here, is that the rings are associated
> with a slide hazard. That's the only context in which I've seen them.
>
> So what good would they do? Obviously they can't stop a landslide.
> Tons of dirt or rock coming down would be enough to first knock the
> fence down and then bury it. Some time later a repair crew shows up
> and finds a big pile of material on the road and perhaps one or two
> fence post tips. There might even be some of these rings in view, but
> what good do they do now? Perhaps there's a car trapped under the slide;
> do they use the rings to hoist up the fence with a crane?
>
> All replies appreciated, even authoritative-sounding but outright
> fabrications.
>
> Sean_Q_
> '99 FLHTCUI / '04 S40 / '81 CB750 AMEN chopper / various derelicts

I have no idea, but this made me think of you:

http://www.ksl.com/index.php?nid=218...cat=144&lpid=6

On Aug 21, 1:41 pm, Sean_Q_ <nos...@no.sapm> wrote:
> I suppose this is a dumb question, but it's something I've been curious
> about for quite a while.
>
> There's a stretch of Marine Drive in N. Vancouver right beneath a very
> steep slope, almost a cliff. The ground is dirt, stabilized by shrubs
> and trees. Right under it, along the side of the road is a chain link
> fence -- with giant steel rings or hoops installed, something like
> in this picture:
>
> http://picasaweb.google.com/nancy.ro...ay212/photo#51...
>
> What are these hoops all about?
>
> Btw I'm fully aware that by its nature this kind of question is
> a wide-open invitation for all kinds of fanciful explanations.
>
> My best guess -- thinking on-line here, is that the rings are associated
> with a slide hazard. That's the only context in which I've seen them.
>
> So what good would they do? Obviously they can't stop a landslide.
> Tons of dirt or rock coming down would be enough to first knock the
> fence down and then bury it. Some time later a repair crew shows up
> and finds a big pile of material on the road and perhaps one or two
> fence post tips. There might even be some of these rings in view, but
> what good do they do now? Perhaps there's a car trapped under the slide;
> do they use the rings to hoist up the fence with a crane?

I think maybe those rings are to help hold the chain link fence in
place.
Looks like there's a good size cable at the top of the chain link.
Maybe the rings help attach the mesh to the vertical posts and/or
cable ?

The whole idea is not to stop a big slide, but rather to keep rocks
from landing on the road in onesies twosies.

> All replies appreciated, even authoritative-sounding but outright
> fabrications.

You asked for it. You got it.

rocks

Rob Kleinschmidt wrote:
>> There's a stretch of Marine Drive in N. Vancouver right beneath a very
>> steep slope, almost a cliff. The ground is dirt, stabilized by shrubs
>> and trees. Right under it, along the side of the road is a chain link
>> fence -- with giant steel rings or hoops installed, something like
>> in this picture:
>>
>> http://picasaweb.google.com/nancy.ro...ay212/photo#51...
>>
>> What are these hoops all about?

The ones I've seen around here (NY) seem to be loops of cable. Probably
to allow the fence to "give" when rocks hit it. It would therefore be
able to stop the rocks better than if it was solid.

--
"Outback" Jon - KC2BNE
outback_jon@ver.no.sp.am.izon.net
AMD Opteron 165 (@2.5) and 6.1 GHz of other AMD power...
http://folding.stanford.edu - got folding? Team 53560

2006 ZG1000A Concours "Blueline" COG# 7385 CDA# 0157

BryanUT wrote:

> this made me think of you:
>
> http://www.ksl.com/index.php?nid=218...cat=144&lpid=6

Thanks for the link. It looks a whole lot like an AMEN Savior frame
with the spring-loaded rear suspension, the kind my buddy at
the blueberry farm has. I'll pass this on so he can see it.

SQ

On Thu, 21 Aug 2008 20:41:19 GMT, Sean_Q_ <nospam@no.sapm> wrote:

>I suppose this is a dumb question, but it's something I've been curious
>about for quite a while.
>
>There's a stretch of Marine Drive in N. Vancouver right beneath a very
>steep slope, almost a cliff. The ground is dirt, stabilized by shrubs
>and trees. Right under it, along the side of the road is a chain link
>fence -- with giant steel rings or hoops installed, something like
>in this picture:
>
>http://picasaweb.google.com/nancy.ro...45414931075842
>
>What are these hoops all about?
>
>Btw I'm fully aware that by its nature this kind of question is
>a wide-open invitation for all kinds of fanciful explanations.
>
>My best guess -- thinking on-line here, is that the rings are associated
>with a slide hazard. That's the only context in which I've seen them.
>

Yeah, that's it. There is a similar fence at Waimea Bay on the North
Shore of Oahu. These are the best pics I could find (1/2 way down):
http://www.gproadwaysolutions.com/construction.html
They're surprisingly strong for what they look like.

--
Turby the Turbosurfer

On Thu, 21 Aug 2008 20:41:19 GMT, Sean_Q_ <nospam@no.sapm> wrote:

>I suppose this is a dumb question, but it's something I've been curious
>about for quite a while.
>
>There's a stretch of Marine Drive in N. Vancouver right beneath a very
>steep slope, almost a cliff. The ground is dirt, stabilized by shrubs
>and trees. Right under it, along the side of the road is a chain link
>fence -- with giant steel rings or hoops installed, something like
>in this picture:
>
>http://picasaweb.google.com/nancy.ro...45414931075842
>
>What are these hoops all about?
>
>Btw I'm fully aware that by its nature this kind of question is
>a wide-open invitation for all kinds of fanciful explanations.
>
>My best guess -- thinking on-line here, is that the rings are associated
>with a slide hazard. That's the only context in which I've seen them.
>
>So what good would they do? Obviously they can't stop a landslide.
>Tons of dirt or rock coming down would be enough to first knock the
>fence down and then bury it. Some time later a repair crew shows up
>and finds a big pile of material on the road and perhaps one or two
>fence post tips. There might even be some of these rings in view, but
>what good do they do now? Perhaps there's a car trapped under the slide;
>do they use the rings to hoist up the fence with a crane?
>
>All replies appreciated, even authoritative-sounding but outright
>fabrications.
>
>Sean_Q_
>'99 FLHTCUI / '04 S40 / '81 CB750 AMEN chopper / various derelicts

I am guessing that they are placed over strategic "weak points" that are
designed to give way above a certain force level and the coiled wire allows for
a greater expansion so in the event of a tremendous rock slide the fence will
bulge and wrap around the rocks and pehaps allow the pile to settle down rather
than being simply bowled over and the rocks then continue tumbling down.

Ben

"Outback Jon" <teammft@ver.no.sp.am.izon.net> wrote in message
news:LBsrk.404$p72.77@trnddc05...
> Rob Kleinschmidt wrote:
>>> There's a stretch of Marine Drive in N. Vancouver right beneath a very
>>> steep slope, almost a cliff. The ground is dirt, stabilized by shrubs
>>> and trees. Right under it, along the side of the road is a chain link
>>> fence -- with giant steel rings or hoops installed, something like
>>> in this picture:
>>>
>>> http://picasaweb.google.com/nancy.ro...ay212/photo#51...
>>>
>>> What are these hoops all about?
>
> The ones I've seen around here (NY) seem to be loops of cable. Probably
> to allow the fence to "give" when rocks hit it. It would therefore be
> able to stop the rocks better than if it was solid.

The look like that to me, too. Here are the two explanations that come to
mind:

a)It may be as simple as avoiding wasting steel cable by cutting it (i.e.
they may be able to re-use the longer lengths in the future). Crimping in
the loops may allow them to adjust the length without cutting the cable so
that they can re-use the cable in the future. (However, there are
counter-arguments ...)

b)If it is to allow "give", I wouldn't be surprised. Earthquake dampers in
buildings are of roughly equivalent design. You have it set up for
destructive friction. It will ruin or degrade the cable as it slides
through the crimp, but in terms of energy or work (force applied over a
distance) it will soak up a lot.