Just to give you an update, the bridge was repaired after
the last section fell down in the earlier Pineapple Express:
https://c4.staticflickr.com/8/7478/15967080150_47ec573ed9_c.jpg
Those earlier storms took down a few nearby Monterey Pines, which
decapitated the Internet access to the bridge & the temporary power:
https://c1.staticflickr.com/9/8598/15849592893_9ce3aaedc1_b.jpg
We had to restring the Internet access in addition to the
electrical lines running for hundreds of feet along the forest floor:
https://c4.staticflickr.com/8/7285/16468720772_94afb91b3e_c.jpg
We also had to detach the bridge from the support at the smaller
redwood trees (which are, themselves, at least 100 feet tall), but
we added a swinging cable, to take some of the load off the cables:
https://c1.staticflickr.com/9/8574/16283420079_f955d6e1ec_c.jpg
Now the bridge is almost at the large redwood tree, almost 100 feet
from the starting point, and now 16 feet wide, instead of the original
10 feet wide for most of the length of the cable bridge:
https://c4.staticflickr.com/8/7426/16283419909_20257e7858_c.jpg
Here is an underside view of the bridge (I can't fit the whole thing
into a single picture because it's too long from the ground looking up):
https://c1.staticflickr.com/9/8642/16467929211_01972b0444_c.jpg
Here's a side view (again, the hillside being what it is, I can't get
the whole thing into a single picture):
https://c4.staticflickr.com/8/7460/16443668456_56a6f74fab_b.jpg
Each section is 16 feet long, by 10 feet wide, and hung on the 3/8"
steel cable for support, and I'd say we're about 30 to 40 feet up:
https://c1.staticflickr.com/9/8598/16281975618_2c7e455b86_b.jpg
We still use the cargo net, slung between the trees, in order to
go back and forth to the big anchoring tree at the far end:
https://c4.staticflickr.com/8/7303/16283420189_5e15a30cd9_c.jpg
We only have about 8 feet to go, and we'll be at the big tree,
and ready to start building the two-story treehouse, which, in the
end, will include running water, electricity, Internet, etc.
https://c4.staticflickr.com/8/7350/16283421279_b0aeced5d3_c.jpg
On Sun, 8 Feb 2015 08:01:33 -0800, "Pico Rico" <[email protected]>
wrote:
>> It's my understanding that the local building codes do not pertain
>> to tree houses.
>>
>
>does your insurance cover it. Like when your buddy takes a header?
>
You fire the help before they hit the ground :)
In article <[email protected]>, John Larkin
<[email protected]> wrote:
> On Sun, 8 Feb 2015 19:10:02 +0000 (UTC), "Danny D."
> <[email protected]> wrote:
>
> >John Larkin wrote, on Sun, 08 Feb 2015 09:39:53 -0800:
> >
> >> Don't all those trees sway (asynchronously!) in the wind?
> >>
> >> You could occasionally get the equivalent of a rogue wave, a big spike
> >> of acceleration.
> >
> >I'm not sure how they sway in the wind, but, we decoupled the 75-foot
> >long bridge from the middle trees after that last storm, and we're
> >hoping to see the bridge still there after the one that is raging as
> >we type.
> > https://c4.staticflickr.com/8/7394/16449145896_d0b70b7c5d_c.jpg
>
> Yeah, we're getting some wild gusts today in the Alemany Gap, a break
> in the coast hills between the ocean and the bay, our own local wind
> tunnel.
>
> https://dl.dropboxusercontent.com/u/53724080/SF/MtSanBruno.JPG
>
> >
> >One thing we noticed is that, in the wind, the bridge actually *rises*
> >a few inches, like what happens with an airplane wing or a sailboat sail.
> >
> >Since the bottom is dirtier, with respect to laminar flow, we suspect
> >the air flows faster over the top than over the bottom:
> > https://c1.staticflickr.com/9/8647/16443668356_137c0b7fba_b.jpg
> >
> >The whole bridge is roughly the size of an airplane wing:
> > https://c1.staticflickr.com/9/8642/16467929211_01972b0444_c.jpg
>
> Yikes. Suspension bridges have all sorts of aerodynamic issues.
> Galloping Gertie and all that.
>
> https://www.youtube.com/watch?v=j-zczJXSxnw
It's called flutter in aerodynamics. This is what happens when the
frequency of the aeolian tone matches the deck-twist resonant
frequency.
When it happens to an airplane wing, the airplane is usually lost.
Look at some of the film clips.
<http://en.wikipedia.org/wiki/Aeroelasticity#Flutter>
<https://www.youtube.com/watch?v=kQI3AWpTWhM>
<https://www.youtube.com/watch?v=fl2Ei7lubrE&list=PL2PSucAZiYkfdJzm_UaYq
vWwY4xeR7hil&index=7>
One can greatly reduce the effect by spacing the boards apart by say an
inch, which will equalize the pressure. The world is full of rope
bridges over chasms, erected by people who never heard of aerodynamics.
<http://en.wikipedia.org/wiki/Aeolian_harp>
The whole idea of rigid decks spanning flexible trees seems destined to
fail.
Joe Gwinn
On Mon, 16 Feb 2015 06:25:51 +0000 (UTC), "Danny D."
<[email protected]> wrote:
>We're not sure how we're going to attach to the big redwood yet
>though, so, that is our next engineering task to figure out
When the dog finally walks out on the structure, you'll have it about
right :)
On Sun, 8 Feb 2015 04:55:14 +0000 (UTC), "Danny D."
<[email protected]> wrote:
>Just to give you an update, the bridge was repaired after
>the last section fell down in the earlier Pineapple Express:
> https://c4.staticflickr.com/8/7478/15967080150_47ec573ed9_c.jpg
>
>Those earlier storms took down a few nearby Monterey Pines, which
>decapitated the Internet access to the bridge & the temporary power:
> https://c1.staticflickr.com/9/8598/15849592893_9ce3aaedc1_b.jpg
>
>We had to restring the Internet access in addition to the
>electrical lines running for hundreds of feet along the forest floor:
> https://c4.staticflickr.com/8/7285/16468720772_94afb91b3e_c.jpg
>
>We also had to detach the bridge from the support at the smaller
>redwood trees (which are, themselves, at least 100 feet tall), but
>we added a swinging cable, to take some of the load off the cables:
> https://c1.staticflickr.com/9/8574/16283420079_f955d6e1ec_c.jpg
>
>Now the bridge is almost at the large redwood tree, almost 100 feet
>from the starting point, and now 16 feet wide, instead of the original
>10 feet wide for most of the length of the cable bridge:
> https://c4.staticflickr.com/8/7426/16283419909_20257e7858_c.jpg
>
>Here is an underside view of the bridge (I can't fit the whole thing
>into a single picture because it's too long from the ground looking up):
> https://c1.staticflickr.com/9/8642/16467929211_01972b0444_c.jpg
>
>Here's a side view (again, the hillside being what it is, I can't get
>the whole thing into a single picture):
> https://c4.staticflickr.com/8/7460/16443668456_56a6f74fab_b.jpg
>
>Each section is 16 feet long, by 10 feet wide, and hung on the 3/8"
>steel cable for support, and I'd say we're about 30 to 40 feet up:
> https://c1.staticflickr.com/9/8598/16281975618_2c7e455b86_b.jpg
>
>We still use the cargo net, slung between the trees, in order to
>go back and forth to the big anchoring tree at the far end:
> https://c4.staticflickr.com/8/7303/16283420189_5e15a30cd9_c.jpg
>
>We only have about 8 feet to go, and we'll be at the big tree,
>and ready to start building the two-story treehouse, which, in the
>end, will include running water, electricity, Internet, etc.
> https://c4.staticflickr.com/8/7350/16283421279_b0aeced5d3_c.jpg
>
Don't all those trees sway (asynchronously!) in the wind?
You could occasionally get the equivalent of a rogue wave, a big spike
of acceleration.
--
John Larkin Highland Technology, Inc
picosecond timing laser drivers and controllers
jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
In article <[email protected]>, Danny D.
<[email protected]> wrote:
> Oren wrote, on Mon, 16 Feb 2015 13:33:25 -0800:
>
> > I forgot about mountain lions over yonder. We have 'em here. I'd be
> > packing some heat in those places you visit and frequent.
>
> There's a funny thing about mountain lions.
>
> They can easily bring down a full-sized buck, so, a puny human
> "should" be easy prey. Given that they're experienced hunters, I doubt
> the human would have much time to see the mountain lion that gets him.
>
> Given that, the mountain lion should "win" against a puny human,
> particularly with the claws and teeth of the mountain lion wrapped
> around a puny human's head, neck, and throat.
>
> So, given that, why aren't there far more mountain lion attacks
> than statistics show?
>
> Clearly, where I hike alone (almost daily), mountain lions abound.
> We have dead deer, dead goats and sheep, and even videos of a mountain
> lion dragging a buck taken by a dash cam on our winding road.
>
> The enigma is that there aren't really a whole lot of documented
> attacks on humans. Sure, humans aren't their standard fare; but
> how do "they" know that?
>
> I'm not worried, but, I do hike in these here hills almost every
> day, and, I haven't yet "seen" a mountain lion (although I've seen
> plenty of dead deer).
The reason is that humans ganged up on and killed critters that dared
to take a human. Over the last say 50,000 years, this enduring bit of
Darwinist pressure had a big effect. Five or six people with spears
are quite capable of killing a lion.
Joe Gwinn
On Sun, 8 Feb 2015 18:51:19 +0000 (UTC), "Danny D."
<[email protected]> wrote:
>Oren wrote, on Sun, 08 Feb 2015 08:21:15 -0800:
>
>> You fire the help before they hit the ground
>
>That's a good idea, to get 'em off the payroll, before they hit
>the ground.
>
>Most of the neighbors have been pitching in, so, that's a large
>payroll to downsize quickly.
>
You bet. Just tell John Law "it was the worse case of suicide I ever
saw!" :)
>Here's a view of the way down from the end closest to the big redwood:
> https://c4.staticflickr.com/8/7299/16449146666_cc1f90346c_c.jpg
On 2/7/2015 10:55 PM, Danny D. wrote:
> Just to give you an update, the bridge was repaired after
> the last section fell down in the earlier Pineapple Express:
> https://c4.staticflickr.com/8/7478/15967080150_47ec573ed9_c.jpg
>
> Those earlier storms took down a few nearby Monterey Pines, which
> decapitated the Internet access to the bridge & the temporary power:
> https://c1.staticflickr.com/9/8598/15849592893_9ce3aaedc1_b.jpg
>
> We had to restring the Internet access in addition to the
> electrical lines running for hundreds of feet along the forest floor:
> https://c4.staticflickr.com/8/7285/16468720772_94afb91b3e_c.jpg
>
> We also had to detach the bridge from the support at the smaller
> redwood trees (which are, themselves, at least 100 feet tall), but
> we added a swinging cable, to take some of the load off the cables:
> https://c1.staticflickr.com/9/8574/16283420079_f955d6e1ec_c.jpg
>
> Now the bridge is almost at the large redwood tree, almost 100 feet
> from the starting point, and now 16 feet wide, instead of the original
> 10 feet wide for most of the length of the cable bridge:
> https://c4.staticflickr.com/8/7426/16283419909_20257e7858_c.jpg
>
> Here is an underside view of the bridge (I can't fit the whole thing
> into a single picture because it's too long from the ground looking up):
> https://c1.staticflickr.com/9/8642/16467929211_01972b0444_c.jpg
>
> Here's a side view (again, the hillside being what it is, I can't get
> the whole thing into a single picture):
> https://c4.staticflickr.com/8/7460/16443668456_56a6f74fab_b.jpg
>
> Each section is 16 feet long, by 10 feet wide, and hung on the 3/8"
> steel cable for support, and I'd say we're about 30 to 40 feet up:
> https://c1.staticflickr.com/9/8598/16281975618_2c7e455b86_b.jpg
>
> We still use the cargo net, slung between the trees, in order to
> go back and forth to the big anchoring tree at the far end:
> https://c4.staticflickr.com/8/7303/16283420189_5e15a30cd9_c.jpg
>
> We only have about 8 feet to go, and we'll be at the big tree,
> and ready to start building the two-story treehouse, which, in the
> end, will include running water, electricity, Internet, etc.
> https://c4.staticflickr.com/8/7350/16283421279_b0aeced5d3_c.jpg
>
>
Sorry to see the work being done over - and such.
We used to live on Hwy 9 off Glengary. Had about 100 of the sprouts
that came up after the clear cut making lumber for SFO. Mine were
between 100 and 130 feet When we left in 2006. Kinda miss the place.
Now I have large oaks and tall pines.
Martin
On 2/16/2015 3:42 PM, Danny D. wrote:
> Roy wrote, on Mon, 16 Feb 2015 11:47:50 -0800:
>
>> I saved a copy of all of those pictures in case I need
>> a "before and after" scenario...but seriously I hope you
>> succeed in your project.
>
> Thanks for your well wishing.
> It is one of a kind, so, we're learning as we go.
> In the end, it will be pretty neat though, don't you think?
>
> It a 10-foot wide suspension bridge, which starts at ground level
> on a path in the redwoods about a thousand feet (or so) from the
> nearest anything, and then goes for about 70 feet to a large
> second-growth redwood, where the deck expands to 16 feet wide.
>
> Sitting on the wide decking, about 40 feet above the ground, will
> be a two story treehouse, with a bathroom, kitchen, electricity,
> gas heating, and WiFi Internet (which is something we're experts
> at by now, given that we all maintain our own radio antennas).
>
> We're thinking of suspending the treehouse with 1/2 inch cable
> wrapped from the big tree to the two smaller trees cradling
> the bridge at about the half-way point that you see to the
> right in this picture.
> https://c4.staticflickr.com/8/7284/16358527150_f314ed76cd_b.jpg
>
> So, that way, the treehouse and the suspension bridge would
> be, in effect, supported separately (or we might make the support
> mutual and redundant).
Redundant would be good. Bridges without redundant support fall down,
e.g. the one in Minnesota--see e.g.
http://www.nytimes.com/2008/01/15/washington/15bridge.html .
We're also thinking of adding downward
> hanging support cables, again from the smaller redwoods to the
> decking, to add redundancy once the treehouse weight goes up.
You can't wrap the cables round the trunks, or you'll kill the trees in
a few years. Nice big eye bolts are the ticket, I expect, provided you
don't put any torque on them (i.e. you have to drill the pilot hole in
the direction of the pull). The tree can easily grow around them,
unlike wraparound cables. The problem with wood fasteners is that they
aren't load rated, unlike machine bolts.
>
> One problem we have been having is we have had to constantly
> adjust the tilt and leveling of the bridge, as weight was added
> to the end. We ended up buying a dozen cable winches, which are
> what is holding the bridge up now, one of which can be seen in
> the left in this photo below.
> https://c4.staticflickr.com/8/7414/16358528340_99ca7a421f_c.jpg
Sure beats turnbuckles.
I think George Dyson probably published construction details of his
famous tree house.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
On Thursday, February 26, 2015 at 7:50:12 PM UTC-5, Danny D. wrote:
> I helped my neighbor with the 75-foot by 16-foot wide (at the tree)
> bridge today, so I figured I'd show you some shots from below:
> https://c1.staticflickr.com/9/8652/16450875917_af82eebc34_c.jpg
>
> Notice in that picture above that there is a "widowmaker" of about
> ten feet long hanging in mid air, ready to fall. Also notice that the
> "sucker" was cut flush, and the boards screwed to it ...just because
> we could.
> https://c1.staticflickr.com/9/8567/16657149282_ea45534049_c.jpg
>
> We're close enough to the big redwood to touch it now!
> https://c1.staticflickr.com/9/8592/16658170035_a640960476_c.jpg
>
> Here's a view, looking down, at the big tree, inches away from it:
> https://c1.staticflickr.com/9/8660/16470768820_6acd2799dd_c.jpg
>
> That's a milestone after so much work starting at the other end.
> https://c1.staticflickr.com/9/8633/16450876947_275ed77b68_c.jpg
>
> I tried to get a picture to take the whole thing, from under:
> https://c1.staticflickr.com/9/8626/16450875757_e3f7fe0fba_c.jpg
>
> But, the best I can show you in a single pic is a side view:
> https://c1.staticflickr.com/9/8584/16656782871_c9052bebfa_c.jpg
It is just me or do I keep seeing haphazard placement of the joists?
Why do some joists appear to be at angles?
What are some deck board spans much longer than others?
Why aren't I seeing 16" or 24" OC joists?
On Sun, 8 Feb 2015 04:55:14 +0000 (UTC), "Danny D."
<[email protected]> wrote:
>Just to give you an update, the bridge was repaired after
>the last section fell down in the earlier Pineapple Express:
> https://c4.staticflickr.com/8/7478/15967080150_47ec573ed9_c.jpg
>
>Those earlier storms took down a few nearby Monterey Pines, which
>decapitated the Internet access to the bridge & the temporary power:
> https://c1.staticflickr.com/9/8598/15849592893_9ce3aaedc1_b.jpg
>
>We had to restring the Internet access in addition to the
>electrical lines running for hundreds of feet along the forest floor:
> https://c4.staticflickr.com/8/7285/16468720772_94afb91b3e_c.jpg
>
>We also had to detach the bridge from the support at the smaller
>redwood trees (which are, themselves, at least 100 feet tall), but
>we added a swinging cable, to take some of the load off the cables:
> https://c1.staticflickr.com/9/8574/16283420079_f955d6e1ec_c.jpg
>
>Now the bridge is almost at the large redwood tree, almost 100 feet
>from the starting point, and now 16 feet wide, instead of the original
>10 feet wide for most of the length of the cable bridge:
> https://c4.staticflickr.com/8/7426/16283419909_20257e7858_c.jpg
>
>Here is an underside view of the bridge (I can't fit the whole thing
>into a single picture because it's too long from the ground looking up):
> https://c1.staticflickr.com/9/8642/16467929211_01972b0444_c.jpg
>
>Here's a side view (again, the hillside being what it is, I can't get
>the whole thing into a single picture):
> https://c4.staticflickr.com/8/7460/16443668456_56a6f74fab_b.jpg
>
>Each section is 16 feet long, by 10 feet wide, and hung on the 3/8"
>steel cable for support, and I'd say we're about 30 to 40 feet up:
> https://c1.staticflickr.com/9/8598/16281975618_2c7e455b86_b.jpg
>
>We still use the cargo net, slung between the trees, in order to
>go back and forth to the big anchoring tree at the far end:
> https://c4.staticflickr.com/8/7303/16283420189_5e15a30cd9_c.jpg
>
>We only have about 8 feet to go, and we'll be at the big tree,
>and ready to start building the two-story treehouse, which, in the
>end, will include running water, electricity, Internet, etc.
> https://c4.staticflickr.com/8/7350/16283421279_b0aeced5d3_c.jpg
>
Is all of this subject to local building codes?
Seems to me somebody is going to end up dead from a long fall.
On 2/16/2015 9:21 PM, Danny D. wrote:
> Phil Hobbs wrote, on Mon, 16 Feb 2015 17:45:37 -0500:
>
>> You can't wrap the cables round the trunks, or you'll kill the trees in
>> a few years.
>
> Actually, if you saw the first pictures, the cables don't actually
> "touch" any tree (this is the smallest pine at the low end):
> https://c3.staticflickr.com/3/2944/15188634078_2b3de04150.jpg
>
> What we did was attach two-by fours to the tree, and then wrap the cables
> around the two by fours.
> https://c4.staticflickr.com/4/3870/15188634228_37f45d19e2_c.jpg
>
> Dunno if that will "protect" the tree or not; but that's why we did
> it that way (in theory).
>
> You'll notice we doubled the cable at *both* ends also, so that
> there are always *two* cables at all points, even around the big
> tree where there is no cable joint at all.
>
Is the cable(s) around the tree adjustable for growth ? Or will the
blocks start to dig in.
Martin
Joe Gwinn <[email protected]> writes:
>In article <[email protected]>, Danny D.
><[email protected]> wrote:
>
>> Oren wrote, on Mon, 16 Feb 2015 13:33:25 -0800:
>>
>> > I forgot about mountain lions over yonder. We have 'em here. I'd be
>> > packing some heat in those places you visit and frequent.
>>
>> There's a funny thing about mountain lions.
>>
>> They can easily bring down a full-sized buck, so, a puny human
>> "should" be easy prey. Given that they're experienced hunters, I doubt
>> the human would have much time to see the mountain lion that gets him.
>>
>> Given that, the mountain lion should "win" against a puny human,
>> particularly with the claws and teeth of the mountain lion wrapped
>> around a puny human's head, neck, and throat.
>>
>> So, given that, why aren't there far more mountain lion attacks
>> than statistics show?
>>
>> Clearly, where I hike alone (almost daily), mountain lions abound.
>> We have dead deer, dead goats and sheep, and even videos of a mountain
>> lion dragging a buck taken by a dash cam on our winding road.
>>
>> The enigma is that there aren't really a whole lot of documented
>> attacks on humans. Sure, humans aren't their standard fare; but
>> how do "they" know that?
>>
>> I'm not worried, but, I do hike in these here hills almost every
>> day, and, I haven't yet "seen" a mountain lion (although I've seen
>> plenty of dead deer).
>
>The reason is that humans ganged up on and killed critters that dared
>to take a human. Over the last say 50,000 years, this enduring bit of
>Darwinist pressure had a big effect. Five or six people with spears
>are quite capable of killing a lion.
I've encountered mountain lions (aka cougar, puma) in both the Santa Teresa foothills
and the Marin headlands. They're sized similar to a medium sized dog
(24" to 36" at the shoulders, 65 to 180 pounds depending on gender and age).
The lions mainly hunt from dusk to dawn, which is one reason that human-lion
encounters are rare. The lions are also not interested in humans as prey.
http://mountainlion.org/FAQfrequentlyaskedquestions.asp
Danny D. wrote:
> Martin Eastburn wrote, on Wed, 18 Feb 2015 23:26:19 -0600:
>
>> Redwood branches tend to die off and fall out from time to time.
>> Not all but here and there. Some are 4-6" in diameter.
>
> Some of those redwood branches are as thick as trees, so that's
> a valid concern. We may need to reinforce the roof, against them
> falling on it.
>
A dozen years ago we owned a lot (around 4 acres) with many large
trees. One huge oak had a horizontal limb about 2 feet in diameter
and I dreamed of putting up a spiral stair and a platform on the limb,
just for fun. We wound up selling the lot instead of building a house
on it, and I went by to look at it a last time and the limb had fallen
off and was lying on the ground.
--
GW Ross
My wife has a slight impediment in
her speech. Every now and then she
stops to breathe. - Jimmy
On Monday, February 9, 2015 at 9:33:20 AM UTC-5, DecadentLinuxUserNumeroUno wrote:
> On Mon, 09 Feb 2015 14:11:29 +0000, Danny D. wrote:
>
> > DecadentLinuxUserNumeroUno wrote, on Mon, 09 Feb 2015 13:02:42 +0000:
> >
> >> You mean a philips screwdriver shank?
> >>
> >> Get a number three. Some of them are square shank, even more
> >> "precise".
> >> And they are certainly bigger.
> >
> > Yes. Sorry. Shank.
> >
> > Actually, truth be admitted, the first two sections were perfectly
> > aligned, but, the next two "curved" a bit, due to the difficulties of
> > getting every board lined up straight while being hung from the cables,
> > so, at times, it's a screwdriver shank on the right side, but an inch
> > (or so) on the left.
>
> "We want to splay... just a little bit longer..." --Jackson Browne
I believe that line is sung right after the bridge.
> >
> > Looking up from below, you can see that these third and fourth 16-foot
> > sections have a larger board-to-board spacing on the right than on the
> > left:
>
> snip
>
> Arc of the Boardament. Just think of railroad tracks.
I've got a Jones to go to Indiana, but the bridge is in CA.
On Sun, 8 Feb 2015 19:10:02 +0000 (UTC), "Danny D."
<[email protected]> wrote:
>John Larkin wrote, on Sun, 08 Feb 2015 09:39:53 -0800:
>
>> Don't all those trees sway (asynchronously!) in the wind?
>>
>> You could occasionally get the equivalent of a rogue wave, a big spike
>> of acceleration.
>
>I'm not sure how they sway in the wind, but, we decoupled the 75-foot
>long bridge from the middle trees after that last storm, and we're
>hoping to see the bridge still there after the one that is raging as
>we type.
> https://c4.staticflickr.com/8/7394/16449145896_d0b70b7c5d_c.jpg
Yeah, we're getting some wild gusts today in the Alemany Gap, a break
in the coast hills between the ocean and the bay, our own local wind
tunnel.
https://dl.dropboxusercontent.com/u/53724080/SF/MtSanBruno.JPG
>
>One thing we noticed is that, in the wind, the bridge actually *rises*
>a few inches, like what happens with an airplane wing or a sailboat sail.
>
>Since the bottom is dirtier, with respect to laminar flow, we suspect
>the air flows faster over the top than over the bottom:
> https://c1.staticflickr.com/9/8647/16443668356_137c0b7fba_b.jpg
>
>The whole bridge is roughly the size of an airplane wing:
> https://c1.staticflickr.com/9/8642/16467929211_01972b0444_c.jpg
Yikes. Suspension bridges have all sorts of aerodynamic issues.
Galloping Gertie and all that.
https://www.youtube.com/watch?v=j-zczJXSxnw
--
John Larkin Highland Technology, Inc
picosecond timing laser drivers and controllers
jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
On Monday, February 9, 2015 at 9:12:08 AM UTC-5, Danny D. wrote:
> DecadentLinuxUserNumeroUno wrote, on Mon, 09 Feb 2015 13:02:42 +0000:
>
> > You mean a philips screwdriver shank?
> >
> > Get a number three. Some of them are square shank, even more "precise".
> > And they are certainly bigger.
>
> Yes. Sorry. Shank.
>
> Actually, truth be admitted, the first two sections were perfectly aligned,
> but, the next two "curved" a bit, due to the difficulties of getting every
> board lined up straight while being hung from the cables, so, at times,
> it's a screwdriver shank on the right side, but an inch (or so) on the left.
>
Make sure that all ladies (or gentlemen) wearing high heels avoid the left side of the bridge.
Danny D. wrote:
> DecadentLinuxUserNumeroUno wrote, on Mon, 16 Feb 2015 19:24:43 +0000:
>
>> Drill a big hole through it, and put a stainless bar through the hole.
>> Voila! Attachment pins!
>
> Right now, the two 16-foot boards to the side of the tree are unattached
> at the tree (they're screwed into the floating bridge only).
> https://c1.staticflickr.com/9/8566/16519997026_ee37d554c5_c.jpg
>
> At the moment, the bridge is wholly supported by the cables and, at the
> low end, by the posts we first cemented into the ground, when we started
> this project in the untrampled woods.
>
> It is time for those attachment pins you speak of though...
>
> What we are thinking is that they sell these $100 treehouse attachment
> bolts, designed specifically for trees (but they're expensive since
> we'd use probably use four or six of them overall).
> http://www.treehousesupplies.com/Treehouse_Bolts_s/41.htm
>
> We can't find anything larger than one-inch wide bolts at our local
> Home Depot, so, we have to order our bolts online, at any measure.
>
> We're debating right now the feasibility of 1 inch or 2 inch bolts,
> which are about twenty bucks each, versus the treehouse attachment
> bolts which are five times as expensive.
> http://treehouseparts.mybigcommerce.com/9-pirch-yellow-zinc-plate-certified-r-32-36-hardness/
>
> So, that's our next question. What kind of bolts make the most sense,
> keeping cost in the equation (if cost were no object, the treehouse
> bolts would do quite well).
>
I don't know what kind of bolt you will use, but here is my experience
with bolts in a living tree: I fastened some wooden squirrel feeders
to trees using lag bolts and washers. In a year the tree grew AROUND
the bolt, pulling it through the plank of the feeder. I learned to
put a spring between the bolt head and the washer to allow for this.
A threaded SS bar through the tree might be a better option, making it
longer than needed so you could back off the nut as the tree grows.
Of course you would want a jam nut so that it would not back off by
itself.
--
GW Ross
I am a mental tourist. My mind
wanders.
On 2/17/2015 7:17 PM, rickman wrote:
> On 2/16/2015 3:24 PM, Danny D. wrote:
>> DecadentLinuxUserNumeroUno wrote, on Mon, 16 Feb 2015 19:24:43 +0000:
>>
>>> Drill a big hole through it, and put a stainless bar through the hole.
>>> Voila! Attachment pins!
>>
>> Right now, the two 16-foot boards to the side of the tree are unattached
>> at the tree (they're screwed into the floating bridge only).
>> https://c1.staticflickr.com/9/8566/16519997026_ee37d554c5_c.jpg
>>
>> At the moment, the bridge is wholly supported by the cables and, at the
>> low end, by the posts we first cemented into the ground, when we started
>> this project in the untrampled woods.
>>
>> It is time for those attachment pins you speak of though...
>>
>> What we are thinking is that they sell these $100 treehouse attachment
>> bolts, designed specifically for trees (but they're expensive since
>> we'd use probably use four or six of them overall).
>> http://www.treehousesupplies.com/Treehouse_Bolts_s/41.htm
>>
>> We can't find anything larger than one-inch wide bolts at our local
>> Home Depot, so, we have to order our bolts online, at any measure.
>>
>> We're debating right now the feasibility of 1 inch or 2 inch bolts,
>> which are about twenty bucks each, versus the treehouse attachment
>> bolts which are five times as expensive.
>>
>> http://treehouseparts.mybigcommerce.com/9-pirch-yellow-zinc-plate-certified-r-32-36-hardness/
>>
>>
>> So, that's our next question. What kind of bolts make the most sense,
>> keeping cost in the equation (if cost were no object, the treehouse
>> bolts would do quite well).
>
> Are these bolts going to support the weight of the bridge? That seems a
> bit awkward with the long length of the board. Does the support board
> run under the bridge to be supported at the other end?
>
> I think rather than drilling into the tree, I would make use of the
> various branches and wrap a line around the tree trunk like a lasso
> somewhat higher up than the walkway. The branches will keep it from
> sliding down the tree without being tight. Drop the line to the walkway
> or even pass it under and back up on the other side to the same or
> another tree.
>
Redwood branches tend to die off and fall out from time to time.
Not all but here and there. Some are 4-6" in diameter. Consider that
but end coming down on you, your car, your shop. One punched through
my shop roof and kept out the rain with all of the green junk on top.
I had to cut it off on top and on the bottom - punch out the disk and
replace the roof boarding. Glad it was in the shop.
Martin - relocated from my 100 or so tall tree home site.
5On Mon, 16 Feb 2015 20:17:24 +0000 (UTC), "Danny D."
<[email protected]> wrote:
>Oren wrote, on Mon, 16 Feb 2015 11:19:58 -0800:
>
>> When the dog finally walks out on the structure, you'll have it about
>> right
>
>Oren, ever since kooties and large feet, I've learned that when you
>say the huckleberries are ripe, the huckleberries are ripe.
>
>I should have taken a picture of it, but, the dog stays mostly on
>the other side of the fence, not even close to the bridge anymore.
>
>Certainly he doesn't venture out on the bridge.
>Some day, I'll snap a picture if he does though.
>
>For you, my friend.
The dog is whispering to you... I'm still your huckleberry, though.
I'd hate to see a bean counter get hurt.
<G>
On Mon, 16 Feb 2015 19:24:43 +0000 (UTC), DecadentLinuxUserNumeroUno
<[email protected]> wrote:
>On Mon, 16 Feb 2015 11:19:58 -0800, Oren wrote:
>
>> On Mon, 16 Feb 2015 06:25:51 +0000 (UTC), "Danny D."
>> <[email protected]> wrote:
>>
>>>We're not sure how we're going to attach to the big redwood yet though,
>>>so, that is our next engineering task to figure out
>>
>> When the dog finally walks out on the structure, you'll have it about
>> right :)
>
>Drill a big hole through it, and put a stainless bar through the hole.
>Voila! Attachment pins!
That should weaken the tree so it is sure to fail. Every see what
happens to trees, in high winds after woodpeckers make a hole in a
loblolly pine tree - they snap off during hurricane winds and
woodpeckers have no place to live (Carolina's - coastal region)
Lots of work.
I live in the redwoods in Fort Bragg.
I have had thoughts of one special tree, and getting to the height where I
can see the ocean....
It is still a dream though.
John
"Danny D." wrote in message news:[email protected]...
Just to give you an update, the bridge was repaired after
the last section fell down in the earlier Pineapple Express:
https://c4.staticflickr.com/8/7478/15967080150_47ec573ed9_c.jpg
Those earlier storms took down a few nearby Monterey Pines, which
decapitated the Internet access to the bridge & the temporary power:
https://c1.staticflickr.com/9/8598/15849592893_9ce3aaedc1_b.jpg
We had to restring the Internet access in addition to the
electrical lines running for hundreds of feet along the forest floor:
https://c4.staticflickr.com/8/7285/16468720772_94afb91b3e_c.jpg
We also had to detach the bridge from the support at the smaller
redwood trees (which are, themselves, at least 100 feet tall), but
we added a swinging cable, to take some of the load off the cables:
https://c1.staticflickr.com/9/8574/16283420079_f955d6e1ec_c.jpg
Now the bridge is almost at the large redwood tree, almost 100 feet
from the starting point, and now 16 feet wide, instead of the original
10 feet wide for most of the length of the cable bridge:
https://c4.staticflickr.com/8/7426/16283419909_20257e7858_c.jpg
Here is an underside view of the bridge (I can't fit the whole thing
into a single picture because it's too long from the ground looking up):
https://c1.staticflickr.com/9/8642/16467929211_01972b0444_c.jpg
Here's a side view (again, the hillside being what it is, I can't get
the whole thing into a single picture):
https://c4.staticflickr.com/8/7460/16443668456_56a6f74fab_b.jpg
Each section is 16 feet long, by 10 feet wide, and hung on the 3/8"
steel cable for support, and I'd say we're about 30 to 40 feet up:
https://c1.staticflickr.com/9/8598/16281975618_2c7e455b86_b.jpg
We still use the cargo net, slung between the trees, in order to
go back and forth to the big anchoring tree at the far end:
https://c4.staticflickr.com/8/7303/16283420189_5e15a30cd9_c.jpg
We only have about 8 feet to go, and we'll be at the big tree,
and ready to start building the two-story treehouse, which, in the
end, will include running water, electricity, Internet, etc.
https://c4.staticflickr.com/8/7350/16283421279_b0aeced5d3_c.jpg
"Danny D." <[email protected]> wrote in message
news:[email protected]...
> Vic Smith wrote, on Sun, 08 Feb 2015 08:49:38 -0600:
>
>> Is all of this subject to local building codes?
>> Seems to me somebody is going to end up dead from a long fall.
>
> It's my understanding that the local building codes do not pertain
> to tree houses.
>
does your insurance cover it. Like when your buddy takes a header?
Oren wrote, on Sun, 08 Feb 2015 08:21:15 -0800:
> You fire the help before they hit the ground
That's a good idea, to get 'em off the payroll, before they hit
the ground.
Most of the neighbors have been pitching in, so, that's a large
payroll to downsize quickly.
Here's a view of the way down from the end closest to the big redwood:
https://c4.staticflickr.com/8/7299/16449146666_cc1f90346c_c.jpg
Roy wrote, on Sun, 08 Feb 2015 09:22:32 -0800:
> Danny, I don't wish you any bad luck and you certainly are
> determined to complete your project BUT it will be for naught.
> Mother nature will get you again. You really need some consulting
> engineers to finish the "project" before it goes down again.
> If your trees never moved it would be a different story but
> the variables are against you.
What? You're not our consulting engineers?
I have proof that we consulted you, and everyone here! :)
To your point, the trees did move in the last Pineapple Express
which caused the last slung section to crumple to the ground:
https://c1.staticflickr.com/9/8681/16154396265_99274620db_c.jpg
It also caused the wood to split in a couple of places:
https://c4.staticflickr.com/8/7335/16281975518_bff97f9956_b.jpg
We determined it was, as you said, because the small trees moved,
so, we detached the bridge from the small redwoods in the middle:
https://c1.staticflickr.com/9/8657/16467930481_1d7505afd3_b.jpg
Now the bridge is no longer attached in the center, to the
small redwoods to either side of the 10-foot-wide section:
https://c4.staticflickr.com/8/7390/16473409901_ddbd3907b2_b.jpg
One other problem is that the bridge "bent" in the middle; but
we'll plan to resolve that when we do the final leveling:
https://c4.staticflickr.com/8/7369/15855045413_bf329e8091_b.jpg
We only have about 8 feet to go, and then we can walk from
ground level, to something like 30 or 40 feet up, over about
75 feet of length, and be flat and level the entire distance:
https://c1.staticflickr.com/9/8647/16443668356_137c0b7fba_b.jpg
John Larkin wrote, on Sun, 08 Feb 2015 09:39:53 -0800:
> Don't all those trees sway (asynchronously!) in the wind?
>
> You could occasionally get the equivalent of a rogue wave, a big spike
> of acceleration.
I'm not sure how they sway in the wind, but, we decoupled the 75-foot
long bridge from the middle trees after that last storm, and we're
hoping to see the bridge still there after the one that is raging as
we type.
https://c4.staticflickr.com/8/7394/16449145896_d0b70b7c5d_c.jpg
One thing we noticed is that, in the wind, the bridge actually *rises*
a few inches, like what happens with an airplane wing or a sailboat sail.
Since the bottom is dirtier, with respect to laminar flow, we suspect
the air flows faster over the top than over the bottom:
https://c1.staticflickr.com/9/8647/16443668356_137c0b7fba_b.jpg
The whole bridge is roughly the size of an airplane wing:
https://c1.staticflickr.com/9/8642/16467929211_01972b0444_c.jpg
Danny D. wrote:
> John Larkin wrote, on Sun, 08 Feb 2015 09:39:53 -0800:
>
>> Don't all those trees sway (asynchronously!) in the wind?
>>
>> You could occasionally get the equivalent of a rogue wave, a big
>> spike of acceleration.
>
> I'm not sure how they sway in the wind, but, we decoupled the 75-foot
> long bridge from the middle trees after that last storm, and we're
> hoping to see the bridge still there after the one that is raging as
> we type.
> https://c4.staticflickr.com/8/7394/16449145896_d0b70b7c5d_c.jpg
>
> One thing we noticed is that, in the wind, the bridge actually *rises*
> a few inches, like what happens with an airplane wing or a sailboat
> sail.
>
> Since the bottom is dirtier, with respect to laminar flow, we suspect
> the air flows faster over the top than over the bottom:
> https://c1.staticflickr.com/9/8647/16443668356_137c0b7fba_b.jpg
>
> The whole bridge is roughly the size of an airplane wing:
> https://c1.staticflickr.com/9/8642/16467929211_01972b0444_c.jpg
I hope you're a better engineer than the pros.
https://www.youtube.com/watch?v=j-zczJXSxnw
Your insurance company will likely cancel you in a moment when they find out
about this.
I am still wondering about the overall width of such a bridge.
I would think, that a smaller width would be stronger, and lighter, and
still manage to carry one over with parts and pieces to the actual tree
house.
just a few thoughts....
john
"Danny D." wrote in message news:[email protected]...
Just to give you an update, the bridge was repaired after
the last section fell down in the earlier Pineapple Express:
https://c4.staticflickr.com/8/7478/15967080150_47ec573ed9_c.jpg
Those earlier storms took down a few nearby Monterey Pines, which
decapitated the Internet access to the bridge & the temporary power:
https://c1.staticflickr.com/9/8598/15849592893_9ce3aaedc1_b.jpg
We had to restring the Internet access in addition to the
electrical lines running for hundreds of feet along the forest floor:
https://c4.staticflickr.com/8/7285/16468720772_94afb91b3e_c.jpg
We also had to detach the bridge from the support at the smaller
redwood trees (which are, themselves, at least 100 feet tall), but
we added a swinging cable, to take some of the load off the cables:
https://c1.staticflickr.com/9/8574/16283420079_f955d6e1ec_c.jpg
Now the bridge is almost at the large redwood tree, almost 100 feet
from the starting point, and now 16 feet wide, instead of the original
10 feet wide for most of the length of the cable bridge:
https://c4.staticflickr.com/8/7426/16283419909_20257e7858_c.jpg
Here is an underside view of the bridge (I can't fit the whole thing
into a single picture because it's too long from the ground looking up):
https://c1.staticflickr.com/9/8642/16467929211_01972b0444_c.jpg
Here's a side view (again, the hillside being what it is, I can't get
the whole thing into a single picture):
https://c4.staticflickr.com/8/7460/16443668456_56a6f74fab_b.jpg
Each section is 16 feet long, by 10 feet wide, and hung on the 3/8"
steel cable for support, and I'd say we're about 30 to 40 feet up:
https://c1.staticflickr.com/9/8598/16281975618_2c7e455b86_b.jpg
We still use the cargo net, slung between the trees, in order to
go back and forth to the big anchoring tree at the far end:
https://c4.staticflickr.com/8/7303/16283420189_5e15a30cd9_c.jpg
We only have about 8 feet to go, and we'll be at the big tree,
and ready to start building the two-story treehouse, which, in the
end, will include running water, electricity, Internet, etc.
https://c4.staticflickr.com/8/7350/16283421279_b0aeced5d3_c.jpg
Joe Gwinn wrote, on Sun, 08 Feb 2015 18:32:00 -0500:
> One can greatly reduce the effect by spacing the boards apart by say an
> inch, which will equalize the pressure.
We're currently using a Philips screwdriver blade as the spacer between boards.
https://c4.staticflickr.com/8/7338/16292599559_4b2c0d8465_c.jpg
Maybe we should use something thicker.
This is a great idea, which I will share with the bridge owner.
Thanks!
On Mon, 09 Feb 2015 02:41:07 +0000, Danny D. wrote:
> Joe Gwinn wrote, on Sun, 08 Feb 2015 18:32:00 -0500:
>
>> One can greatly reduce the effect by spacing the boards apart by say an
>> inch, which will equalize the pressure.
>
> We're currently using a Philips screwdriver blade as the spacer between
> boards.
> https://c4.staticflickr.com/8/7338/16292599559_4b2c0d8465_c.jpg
>
> Maybe we should use something thicker.
> This is a great idea, which I will share with the bridge owner.
>
> Thanks!
You mean a philips screwdriver shank?
Get a number three. Some of them are square shank, even more "precise".
And they are certainly bigger.
DecadentLinuxUserNumeroUno wrote, on Mon, 09 Feb 2015 13:02:42 +0000:
> You mean a philips screwdriver shank?
>
> Get a number three. Some of them are square shank, even more "precise".
> And they are certainly bigger.
Yes. Sorry. Shank.
Actually, truth be admitted, the first two sections were perfectly aligned,
but, the next two "curved" a bit, due to the difficulties of getting every
board lined up straight while being hung from the cables, so, at times,
it's a screwdriver shank on the right side, but an inch (or so) on the left.
Looking up from below, you can see that these third and fourth 16-foot
sections have a larger board-to-board spacing on the right than on the left:
https://c1.staticflickr.com/9/8632/16287716260_ab60268c0b_c.jpg
On Mon, 09 Feb 2015 14:11:29 +0000, Danny D. wrote:
> DecadentLinuxUserNumeroUno wrote, on Mon, 09 Feb 2015 13:02:42 +0000:
>
>> You mean a philips screwdriver shank?
>>
>> Get a number three. Some of them are square shank, even more
>> "precise".
>> And they are certainly bigger.
>
> Yes. Sorry. Shank.
>
> Actually, truth be admitted, the first two sections were perfectly
> aligned, but, the next two "curved" a bit, due to the difficulties of
> getting every board lined up straight while being hung from the cables,
> so, at times, it's a screwdriver shank on the right side, but an inch
> (or so) on the left.
"We want to splay... just a little bit longer..." --Jackson Browne
>
> Looking up from below, you can see that these third and fourth 16-foot
> sections have a larger board-to-board spacing on the right than on the
> left:
snip
Arc of the Boardament. Just think of railroad tracks.
We reached a milestone this lovely sunny VD weekend in the mountains:
https://c4.staticflickr.com/8/7370/16360101847_a148c61f1f_c.jpg
After four 16-foot sections, we're only about 4 or 5 feet from the tree:
https://c1.staticflickr.com/9/8637/16359718379_a6cbb11e00_c.jpg
I can't get the whole bridge in the picture, but here's a side view:
https://c4.staticflickr.com/8/7284/16358527150_f314ed76cd_b.jpg
Here's an angled view showing the 10-foot wide sections:
https://c4.staticflickr.com/8/7370/16544303031_3c0511bfaf_b.jpg
And, here's a view showing the last set of 16-foot wide boards:
https://c4.staticflickr.com/8/7414/16358528340_99ca7a421f_c.jpg
We're not sure how we're going to attach the end to the tree though:
https://c4.staticflickr.com/8/7359/16358325088_d238b3ab6b_b.jpg
We wrestled two 16 foot beams to either side of the big tree for now:
https://c1.staticflickr.com/9/8566/16519997026_ee37d554c5_c.jpg
We're not sure how we're going to attach to the big redwood yet
though, so, that is our next engineering task to figure out.
On Mon, 16 Feb 2015 11:19:58 -0800, Oren wrote:
> On Mon, 16 Feb 2015 06:25:51 +0000 (UTC), "Danny D."
> <[email protected]> wrote:
>
>>We're not sure how we're going to attach to the big redwood yet though,
>>so, that is our next engineering task to figure out
>
> When the dog finally walks out on the structure, you'll have it about
> right :)
Drill a big hole through it, and put a stainless bar through the hole.
Voila! Attachment pins!
Oren wrote, on Mon, 16 Feb 2015 11:19:58 -0800:
> When the dog finally walks out on the structure, you'll have it about
> right
Oren, ever since kooties and large feet, I've learned that when you
say the huckleberries are ripe, the huckleberries are ripe.
I should have taken a picture of it, but, the dog stays mostly on
the other side of the fence, not even close to the bridge anymore.
Certainly he doesn't venture out on the bridge.
Some day, I'll snap a picture if he does though.
For you, my friend.
DecadentLinuxUserNumeroUno wrote, on Mon, 16 Feb 2015 19:24:43 +0000:
> Drill a big hole through it, and put a stainless bar through the hole.
> Voila! Attachment pins!
Right now, the two 16-foot boards to the side of the tree are unattached
at the tree (they're screwed into the floating bridge only).
https://c1.staticflickr.com/9/8566/16519997026_ee37d554c5_c.jpg
At the moment, the bridge is wholly supported by the cables and, at the
low end, by the posts we first cemented into the ground, when we started
this project in the untrampled woods.
It is time for those attachment pins you speak of though...
What we are thinking is that they sell these $100 treehouse attachment
bolts, designed specifically for trees (but they're expensive since
we'd use probably use four or six of them overall).
http://www.treehousesupplies.com/Treehouse_Bolts_s/41.htm
We can't find anything larger than one-inch wide bolts at our local
Home Depot, so, we have to order our bolts online, at any measure.
We're debating right now the feasibility of 1 inch or 2 inch bolts,
which are about twenty bucks each, versus the treehouse attachment
bolts which are five times as expensive.
http://treehouseparts.mybigcommerce.com/9-pirch-yellow-zinc-plate-certified-r-32-36-hardness/
So, that's our next question. What kind of bolts make the most sense,
keeping cost in the equation (if cost were no object, the treehouse
bolts would do quite well).
Roy wrote, on Mon, 16 Feb 2015 11:47:50 -0800:
> I saved a copy of all of those pictures in case I need
> a "before and after" scenario...but seriously I hope you
> succeed in your project.
Thanks for your well wishing.
It is one of a kind, so, we're learning as we go.
In the end, it will be pretty neat though, don't you think?
It a 10-foot wide suspension bridge, which starts at ground level
on a path in the redwoods about a thousand feet (or so) from the
nearest anything, and then goes for about 70 feet to a large
second-growth redwood, where the deck expands to 16 feet wide.
Sitting on the wide decking, about 40 feet above the ground, will
be a two story treehouse, with a bathroom, kitchen, electricity,
gas heating, and WiFi Internet (which is something we're experts
at by now, given that we all maintain our own radio antennas).
We're thinking of suspending the treehouse with 1/2 inch cable
wrapped from the big tree to the two smaller trees cradling
the bridge at about the half-way point that you see to the
right in this picture.
https://c4.staticflickr.com/8/7284/16358527150_f314ed76cd_b.jpg
So, that way, the treehouse and the suspension bridge would
be, in effect, supported separately (or we might make the support
mutual and redundant). We're also thinking of adding downward
hanging support cables, again from the smaller redwoods to the
decking, to add redundancy once the treehouse weight goes up.
One problem we have been having is we have had to constantly
adjust the tilt and leveling of the bridge, as weight was added
to the end. We ended up buying a dozen cable winches, which are
what is holding the bridge up now, one of which can be seen in
the left in this photo below.
https://c4.staticflickr.com/8/7414/16358528340_99ca7a421f_c.jpg
We also may erect a few more nets so that we can walk out to
the neighboring trees. In fact, if you look closely, you can
see two different nets in the picture above. One is to the
top left of the picture, and the other is in the center right,
in the big redwood tree itself, where someone spent months
sleeping in and writing a book, many years ago (his net is
still there, 40 feet up in the tree; but we would replace it
as it's not safe to use probably, being fifty years old).
Oren wrote, on Mon, 16 Feb 2015 12:54:30 -0800:
> The dog is whispering to you... I'm still your huckleberry, though.
>
> I'd hate to see a bean counter get hurt.
:)
Interestingly, that dog is fantastically protective!
When the mountain lion came by, and we didn't know it, he was
barking and yelping like crazy and growling, which is not his
normal nature. It was only later, when one of the animals got
killed, during the storm, where the dog was locked inside,
that we had realized what he was making all that commotion about.
So, now, the dog stays outside, with the rest of the animals,
to protect them, even during the storms (which may have abated
until next winter, by now).
On Mon, 16 Feb 2015 11:55:31 -0800, Oren wrote:
> That should weaken the tree so it is sure to fail.
You should get a less weak grip of the facts.
A one inch hole drilled through the center meat of a Redwood? Hardly.
The stainless bar finishes the task. The tree would have no problem
growing around the bar, and even if it did not, it would not weaken the
tree ANY significant amount.
If the tree could take a 30 ton tornado force before, now it can only
take a 29.8 ton force.
Pretty much negligible, is the point.
You'd break the gear you hang on the pins before you'd break the pins or
the tree.
On Mon, 16 Feb 2015 20:24:59 +0000, Danny D. wrote:
> We can't find anything larger than one-inch wide bolts at our local Home
> Depot, so, we have to order our bolts online, at any measure.
Just order the stainless bar stock and have your local auto machine shop
of chopper shop cut threads onto the ends.
Get square bar stock if you want to keep it from rotating.
Oren wrote, on Mon, 16 Feb 2015 13:33:25 -0800:
> I forgot about mountain lions over yonder. We have 'em here. I'd be
> packing some heat in those places you visit and frequent.
There's a funny thing about mountain lions.
They can easily bring down a full-sized buck, so, a puny human
"should" be easy prey. Given that they're experienced hunters, I doubt
the human would have much time to see the mountain lion that gets him.
Given that, the mountain lion should "win" against a puny human,
particularly with the claws and teeth of the mountain lion wrapped
around a puny human's head, neck, and throat.
So, given that, why aren't there far more mountain lion attacks
than statistics show?
Clearly, where I hike alone (almost daily), mountain lions abound.
We have dead deer, dead goats and sheep, and even videos of a mountain
lion dragging a buck taken by a dash cam on our winding road.
The enigma is that there aren't really a whole lot of documented
attacks on humans. Sure, humans aren't their standard fare; but
how do "they" know that?
I'm not worried, but, I do hike in these here hills almost every
day, and, I haven't yet "seen" a mountain lion (although I've seen
plenty of dead deer).
Phil Hobbs wrote, on Mon, 16 Feb 2015 17:45:37 -0500:
> You can't wrap the cables round the trunks, or you'll kill the trees in
> a few years.
Actually, if you saw the first pictures, the cables don't actually
"touch" any tree (this is the smallest pine at the low end):
https://c3.staticflickr.com/3/2944/15188634078_2b3de04150.jpg
What we did was attach two-by fours to the tree, and then wrap the cables
around the two by fours.
https://c4.staticflickr.com/4/3870/15188634228_37f45d19e2_c.jpg
Dunno if that will "protect" the tree or not; but that's why we did
it that way (in theory).
You'll notice we doubled the cable at *both* ends also, so that
there are always *two* cables at all points, even around the big
tree where there is no cable joint at all.
Danny D. wrote:
> Oren wrote, on Mon, 16 Feb 2015 13:33:25 -0800:
>
>> I forgot about mountain lions over yonder. We have 'em here. I'd be
>> packing some heat in those places you visit and frequent.
>
> There's a funny thing about mountain lions.
>
> They can easily bring down a full-sized buck, so, a puny human
> "should" be easy prey. Given that they're experienced hunters, I doubt
> the human would have much time to see the mountain lion that gets him.
>
> Given that, the mountain lion should "win" against a puny human,
> particularly with the claws and teeth of the mountain lion wrapped
> around a puny human's head, neck, and throat.
>
> So, given that, why aren't there far more mountain lion attacks
> than statistics show?
>
> Clearly, where I hike alone (almost daily), mountain lions abound.
> We have dead deer, dead goats and sheep, and even videos of a mountain
> lion dragging a buck taken by a dash cam on our winding road.
>
> The enigma is that there aren't really a whole lot of documented
> attacks on humans. Sure, humans aren't their standard fare; but
> how do "they" know that?
>
> I'm not worried, but, I do hike in these here hills almost every
> day, and, I haven't yet "seen" a mountain lion (although I've seen
> plenty of dead deer).
Boy - you can surely take a thread off to different places... Not that this
one really ever did have a place on rec.woodworking in the first place.
--
-Mike-
[email protected]
On 2/16/2015 3:24 PM, Danny D. wrote:
> DecadentLinuxUserNumeroUno wrote, on Mon, 16 Feb 2015 19:24:43 +0000:
>
>> Drill a big hole through it, and put a stainless bar through the hole.
>> Voila! Attachment pins!
>
> Right now, the two 16-foot boards to the side of the tree are unattached
> at the tree (they're screwed into the floating bridge only).
> https://c1.staticflickr.com/9/8566/16519997026_ee37d554c5_c.jpg
>
> At the moment, the bridge is wholly supported by the cables and, at the
> low end, by the posts we first cemented into the ground, when we started
> this project in the untrampled woods.
>
> It is time for those attachment pins you speak of though...
>
> What we are thinking is that they sell these $100 treehouse attachment
> bolts, designed specifically for trees (but they're expensive since
> we'd use probably use four or six of them overall).
> http://www.treehousesupplies.com/Treehouse_Bolts_s/41.htm
>
> We can't find anything larger than one-inch wide bolts at our local
> Home Depot, so, we have to order our bolts online, at any measure.
>
> We're debating right now the feasibility of 1 inch or 2 inch bolts,
> which are about twenty bucks each, versus the treehouse attachment
> bolts which are five times as expensive.
> http://treehouseparts.mybigcommerce.com/9-pirch-yellow-zinc-plate-certified-r-32-36-hardness/
>
> So, that's our next question. What kind of bolts make the most sense,
> keeping cost in the equation (if cost were no object, the treehouse
> bolts would do quite well).
Are these bolts going to support the weight of the bridge? That seems a
bit awkward with the long length of the board. Does the support board
run under the bridge to be supported at the other end?
I think rather than drilling into the tree, I would make use of the
various branches and wrap a line around the tree trunk like a lasso
somewhat higher up than the walkway. The branches will keep it from
sliding down the tree without being tight. Drop the line to the walkway
or even pass it under and back up on the other side to the same or
another tree.
--
Rick
rickman wrote, on Tue, 17 Feb 2015 20:17:21 -0500:
> Are these bolts going to support the weight of the bridge? That seems a
> bit awkward with the long length of the board. Does the support board
> run under the bridge to be supported at the other end?
The bridge is already supported.
It's supported by a 3/8-inch suspension cable on both sides.
The bolts are simply for redundancy, and, because the treehouse, when
built, will add additional weight, even if/when the cable is suspended
for the treehouse itself.
> I think rather than drilling into the tree, I would make use of the
> various branches and wrap a line around the tree trunk like a lasso
> somewhat higher up than the walkway. The branches will keep it from
> sliding down the tree without being tight. Drop the line to the walkway
> or even pass it under and back up on the other side to the same or
> another tree.
We haven't decided what to do with the branches yet.
Martin Eastburn wrote, on Wed, 18 Feb 2015 23:26:19 -0600:
> Redwood branches tend to die off and fall out from time to time.
> Not all but here and there. Some are 4-6" in diameter.
Some of those redwood branches are as thick as trees, so that's
a valid concern. We may need to reinforce the roof, against them
falling on it.
I helped my neighbor with the 75-foot by 16-foot wide (at the tree)
bridge today, so I figured I'd show you some shots from below:
https://c1.staticflickr.com/9/8652/16450875917_af82eebc34_c.jpg
Notice in that picture above that there is a "widowmaker" of about
ten feet long hanging in mid air, ready to fall. Also notice that the
"sucker" was cut flush, and the boards screwed to it ...just because
we could.
https://c1.staticflickr.com/9/8567/16657149282_ea45534049_c.jpg
We're close enough to the big redwood to touch it now!
https://c1.staticflickr.com/9/8592/16658170035_a640960476_c.jpg
Here's a view, looking down, at the big tree, inches away from it:
https://c1.staticflickr.com/9/8660/16470768820_6acd2799dd_c.jpg
That's a milestone after so much work starting at the other end.
https://c1.staticflickr.com/9/8633/16450876947_275ed77b68_c.jpg
I tried to get a picture to take the whole thing, from under:
https://c1.staticflickr.com/9/8626/16450875757_e3f7fe0fba_c.jpg
But, the best I can show you in a single pic is a side view:
https://c1.staticflickr.com/9/8584/16656782871_c9052bebfa_c.jpg
On Tue, 17 Feb 2015 13:21:49 +1000, Danny D. <[email protected]>
wrote:
> Phil Hobbs wrote, on Mon, 16 Feb 2015 17:45:37 -0500:
>
>> You can't wrap the cables round the trunks, or you'll kill the trees in
>> a few years.
>
> Actually, if you saw the first pictures, the cables don't actually
> "touch" any tree (this is the smallest pine at the low end):
> https://c3.staticflickr.com/3/2944/15188634078_2b3de04150.jpg
>
> What we did was attach two-by fours to the tree, and then wrap the cables
> around the two by fours.
> https://c4.staticflickr.com/4/3870/15188634228_37f45d19e2_c.jpg
>
> Dunno if that will "protect" the tree or not; but that's why we did
> it that way (in theory).
>
> You'll notice we doubled the cable at *both* ends also, so that
> there are always *two* cables at all points, even around the big
> tree where there is no cable joint at all.
Actually a bolt through the tree is the least damaging way to attach
something. The comparison with woodpeckers nests is not valid - they make
large holes that greatly interfere with sap flow. Methods wrapping around
a trunk can do enormous damage as the tree grows, including effectively
ring-barking (hence killing) the tree.
On Tue, 17 Feb 2015 13:21:49 +1000, Danny D. <[email protected]>
wrote:
> Phil Hobbs wrote, on Mon, 16 Feb 2015 17:45:37 -0500:
>
>> You can't wrap the cables round the trunks, or you'll kill the trees in
>> a few years.
>
> Actually, if you saw the first pictures, the cables don't actually
> "touch" any tree (this is the smallest pine at the low end):
> https://c3.staticflickr.com/3/2944/15188634078_2b3de04150.jpg
>
> What we did was attach two-by fours to the tree, and then wrap the cables
> around the two by fours.
> https://c4.staticflickr.com/4/3870/15188634228_37f45d19e2_c.jpg
>
> Dunno if that will "protect" the tree or not; but that's why we did
> it that way (in theory).
>
> You'll notice we doubled the cable at *both* ends also, so that
> there are always *two* cables at all points, even around the big
> tree where there is no cable joint at all.
Shouldn't there be a forestry or similar department you could ask for
advice?
On Mon, 16 Feb 2015 20:56:18 +0000 (UTC), "Danny D."
<[email protected]> wrote:
>Oren wrote, on Mon, 16 Feb 2015 12:54:30 -0800:
>
>> The dog is whispering to you... I'm still your huckleberry, though.
>>
>> I'd hate to see a bean counter get hurt.
>
>:)
>
>Interestingly, that dog is fantastically protective!
>
>When the mountain lion came by, and we didn't know it, he was
>barking and yelping like crazy and growling, which is not his
>normal nature. It was only later, when one of the animals got
>killed, during the storm, where the dog was locked inside,
>that we had realized what he was making all that commotion about.
>
>So, now, the dog stays outside, with the rest of the animals,
>to protect them, even during the storms (which may have abated
>until next winter, by now).
I forgot about mountain lions over yonder. We have 'em here. I'd be
packing some heat in those places you visit and frequent.
Good luck.
On Fri, 20 Feb 2015 20:01:51 GMT, [email protected] (Scott Lurndal)
wrote:
>Joe Gwinn <[email protected]> writes:
>>In article <[email protected]>, Danny D.
>><[email protected]> wrote:
>>
>>> Oren wrote, on Mon, 16 Feb 2015 13:33:25 -0800:
>>>
>>> > I forgot about mountain lions over yonder. We have 'em here. I'd be
>>> > packing some heat in those places you visit and frequent.
>>>
>>> There's a funny thing about mountain lions.
>>>
>>> They can easily bring down a full-sized buck, so, a puny human
>>> "should" be easy prey. Given that they're experienced hunters, I doubt
>>> the human would have much time to see the mountain lion that gets him.
>>>
>>> Given that, the mountain lion should "win" against a puny human,
>>> particularly with the claws and teeth of the mountain lion wrapped
>>> around a puny human's head, neck, and throat.
>>>
>>> So, given that, why aren't there far more mountain lion attacks
>>> than statistics show?
>>>
>>> Clearly, where I hike alone (almost daily), mountain lions abound.
>>> We have dead deer, dead goats and sheep, and even videos of a mountain
>>> lion dragging a buck taken by a dash cam on our winding road.
>>>
>>> The enigma is that there aren't really a whole lot of documented
>>> attacks on humans. Sure, humans aren't their standard fare; but
>>> how do "they" know that?
>>>
>>> I'm not worried, but, I do hike in these here hills almost every
>>> day, and, I haven't yet "seen" a mountain lion (although I've seen
>>> plenty of dead deer).
>>
>>The reason is that humans ganged up on and killed critters that dared
>>to take a human. Over the last say 50,000 years, this enduring bit of
>>Darwinist pressure had a big effect. Five or six people with spears
>>are quite capable of killing a lion.
>
>I've encountered mountain lions (aka cougar, puma) in both the Santa Teresa foothills
>and the Marin headlands. They're sized similar to a medium sized dog
>(24" to 36" at the shoulders, 65 to 180 pounds depending on gender and age).
>
>The lions mainly hunt from dusk to dawn, which is one reason that human-lion
>encounters are rare. The lions are also not interested in humans as prey.
>
>http://mountainlion.org/FAQfrequentlyaskedquestions.asp
I encountered one in my back yard. Awakened by the dog barking very
strangely, I stuck my head out the arcadia door to encounter mountain
lion with my dog standing on top of his dog house shaking like crazy
;-)
Mountain lion took off like a bullet.
...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| San Tan Valley, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
On 2/8/2015 4:13 PM, John Larkin wrote:
> Yikes. Suspension bridges have all sorts of aerodynamic issues.
> Galloping Gertie and all that.
>
> https://www.youtube.com/watch?v=j-zczJXSxnw
Susceptibility to vibration and resonance.
Why soldiers "route step" when marching across bridges.
--
eWoodShop: www.eWoodShop.com
Wood Shop: www.e-WoodShop.net
https://www.google.com/+eWoodShop
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http://www.custommade.com/by/ewoodshop/
KarlCaillouet@ (the obvious)