We started the 100-foot long 10-foot wide deck high up in th

[Danny D.]

VinnyB wrote, on Wed, 22 Oct 2014 05:58:58 -0500:

The lawyers are going to love it. Everyone from the wire rope
manufacturer to the water-boy will be sued.

You forgot the screw manufacturers!
https://c4.staticflickr.com/4/3935/15025811753_8de1cc2650_b.jpg

Notice we gave up on the lower screw (the one with the longer thread).

It was just too hard to drive into the wood.

Even with this nice pile driver thing from Harbor Freight!
https://c4.staticflickr.com/4/3934/15459836048_8f3a566c90_b.jpg

The screw on top, with the shorter thread, goes in without pounding!

 

[Ian Malcolm]

"Danny D." <dannydiamico@gmail.com> wrote in
news:m2mk88$c0c$5@dont-email.me:

josephkk wrote, on Thu, 23 Oct 2014 18:23:37 -0700:

I see a complete failure to account for wind loads. Wind loads on
this tree house will be larger than the dead loads. Ask the owner to
calculate the wind loads as well.

This is a good point so I will mention it to him.

We worked on the second floating 16-foot section today, by the way.
https://c4.staticflickr.com/4/3955/15459997077_b22b960f68_b.jpg

So now we're suspended 32 feet straight out.

Only 60 or so feet to go!

See <http://en.wikipedia.org/wiki/Tacoma_Narrows_Bridge_(1940)>
The chances of your bridge deck fluttering in a blow are fairly high.

--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & >32K emails --> NUL

 

[Danny D.]

Ian Malcolm wrote, on Tue, 28 Oct 2014 00:21:08 +0000:

See <http://en.wikipedia.org/wiki/Tacoma_Narrows_Bridge_(1940)
The chances of your bridge deck fluttering in a blow are fairly high.

We actually joked, a few times, about the Tacoma Narrows bridge, and,
yes, I think just about everyone has seen that video of the car on
the bridge and the person getting out and making it just in time.

This bridge isn't nearly as long.

It's only about 100 feet long, by 10 feet wide, supported on one end
on the ground and on the far end about 40 or 50 feet up in a tree on
a (very) steep slope.

Here's what the first two 16-foot-long sections looked like today,
when we ran out of oiled wood:
https://c4.staticflickr.com/4/3945/15459995717_3722bf0914_b.jpg

I'm currently learning how to wash good clothes to get the oil
out!

 

[Danny D.]

dpb wrote, on Thu, 23 Oct 2014 08:13:06 -0500:

ERRATUM: I forgot to divide the cable limit by the two above
-- the actual limit per cable is (optimistically) as used by
your friend 14000, not 28000.

Here's the response from the neighbor building the deck...
https://c4.staticflickr.com/4/3953/15460990220_5b1f28763d_b.jpg

The 3/8" steel suspension cable is a good deal higher than 10 feet above
the deck at the ends. Currently that 3/8" steel cable is anchored at a
tree about 25 feet above the deck at the beginning end of the deck.

Also, the 100 foot final length of the deck was a guess that is probably
a bit high, where perhaps 80 feet might be closer to the final length. So
the 11 degrees may no longer still be the result of the calculations.

Looking at the photos, the angle of the cable looks like around 30
degrees to me. If the height of the suspension cable above the deck is 25
feet, and the length of the deck is 80 feet, we now have 32 degrees.

Using his tension formula, we get a tension of 4,718 pounds.
So, I believe, that means the 3/8" suspension cable can support almost
six times what we are assuming.

While the deck was originally supposed to be free floating, since we
decided to anchor the close end of the deck on the dirt path (so that
people could just step onto the deck from the path), that end of the deck
is now supported by the two fence posts, so half of its weight goes away.

If, additionally, we add another fence post, in a "T" shape support, at
the end of the first 16-foot-long section, then the weight of that first
16-foot-long section goes away completely, as does half the weight of the
next 16-foot-long section. And we still have the option of supporting the
other half by attaching it to the small redwood trees, along with half of
the third section.

If we really did get to 28,000 pounds of tension, the trees would pull
closer together, reducing the distance, and making the angle steeper. It
thus gets asymptotically harder to actually put that much tension on the
cable.

The treehouse itself, when it's built, will be supported mostly by the
redwood trees.

 

[Danny D.]

Arfa Daily wrote, on Tue, 28 Oct 2014 02:05:05 +0000:

... in view of the - how shall we put it - challenging ? - nature of the
site, wouldn't it be a good idea to have your specs on one of those
strings around your neck ? And tools like hammers, roped to your belt ?

That's a good suggestion, as we have tools all over the place!
https://c4.staticflickr.com/4/3948/15647694665_4bc6370a50_c.jpg

Usually, we tie in when we're out on the cable, with no firm footing:
https://c4.staticflickr.com/4/3947/15461051649_0ffee9cb37_b.jpg

And, we tie in when we're working on the steep slope below the deck:
https://c4.staticflickr.com/4/3950/15461715927_30b042e8a8_b.jpg

The harnesses we use are the same ones we use for climbing the hills:
https://c2.staticflickr.com/6/5602/15026942014_d22eb1ee32_b.jpg

Here's my setup, for example, as I was digging the fence post holes:
https://c4.staticflickr.com/4/3950/15461715927_30b042e8a8_b.jpg

And, here's what I used when I had to double-line rappel downslope:
https://c4.staticflickr.com/4/3932/15648510152_b903b1b22c_c.jpg

Even so, we've had a few of the typical gotchas, from dropping the
spool of wire (where it rolled a hundred or so feet downhill before
getting wedge under a fallen tree) to the inevitable search for missing
glasses and hammers.

Such is the nature of working in the trees...

 

[Danny D.]

dpb wrote, on Mon, 27 Oct 2014 21:06:58 -0500:

https://c4.staticflickr.com/4/3943/15645979325_89a8481615_b.jpg
Where are the supporting cables in the picture--on top or
just hidden by the view?

All the supporting cables are above the deck.

It's a bit hard to see in that picture from below today, but the 3/8"
steel cable is glinting in the sunlight a few feet *above* the deck.
https://c4.staticflickr.com/4/3943/15645979325_89a8481615_b.jpg

The deck is not attached to *anything* other than the cable on the free-
floating end, as we build it out. In fact, while it's hard to tell from
the angle of this picture, but the end of the second 16-foot-long section
is still shy of the leftmost redwood by about a foot, and maybe it's two
feet shy of the right-most redwood tree:
https://c2.staticflickr.com/6/5600/15648508432_8ea7136264_c.jpg

Here is a picture taken earlier in the day, before we planked the second
16-foot-long section, showing how the 10-foot-wide deck is suspended from
the steel cables (this is the second of the two 16-foot-long sections):
https://c2.staticflickr.com/6/5601/15026940484_8853aa5e3e_c.jpg

 

[Danny D.]

dpb wrote, on Mon, 27 Oct 2014 21:06:58 -0500:

You also need to consider how much side load this is putting on those
trees and how large they are at that point to handle the lateral load
plus how well their root systems are capable of that additional
continuous load, particularly when the ground gets saturated when it
finally does rain again...

This is a good point, in that sometimes it pours out here, and this is a
steep slope, so the runoff could be great.

We just had a half inch of rain over the weekend, and this is a shot of
the cables and the people on the decking (the dog won't go on the deck):
https://c4.staticflickr.com/4/3953/15460990220_5b1f28763d_b.jpg

We're still about a foot from the left-most redwood here, and about two
feet from the right-most redwood, so we "can" attach to them (if decided)
with the third 16-foot deck section:
https://c2.staticflickr.com/6/5600/15648508432_8ea7136264_c.jpg

 

[Arfa Daily]

"Danny D." <dannydiamico@gmail.com> wrote in message
news:m2mkq5$c0c$7@dont-email.me...

CRNG wrote, on Thu, 23 Oct 2014 12:40:15 -0500:

I don't think they are taking heed. They have been successful with
their little neighborhood projects, and they are starting to get over
confident.

I think the owner is taking heed, it's just that he's a third party
to this conversation (he doesn't know Usenet).

BTW, here's a view from below today, when I dropped my glasses
and had to climb down the steep hill to retrieve them.

https://c4.staticflickr.com/4/3943/15645979325_89a8481615_b.jpg

Pardon me for a silly suggestion but ...

.... in view of the - how shall we put it - challenging ? - nature of the
site, wouldn't it be a good idea to have your specs on one of those strings
around your neck ? And tools like hammers, roped to your belt ?

Arfa

 

[Arfa Daily]

"Danny D." <dannydiamico@gmail.com> wrote in message
news:m2n5iq$c0c$26@dont-email.me...

Arfa Daily wrote, on Tue, 28 Oct 2014 02:05:05 +0000:

... in view of the - how shall we put it - challenging ? - nature of the
site, wouldn't it be a good idea to have your specs on one of those
strings around your neck ? And tools like hammers, roped to your belt ?

That's a good suggestion, as we have tools all over the place!
https://c4.staticflickr.com/4/3948/15647694665_4bc6370a50_c.jpg

Boy oh boy ... I thought I was making a bit of a silly suggestion there ...

Usually, we tie in when we're out on the cable, with no firm footing:
https://c4.staticflickr.com/4/3947/15461051649_0ffee9cb37_b.jpg

Work clothes ?

And, we tie in when we're working on the steep slope below the deck:
https://c4.staticflickr.com/4/3950/15461715927_30b042e8a8_b.jpg

That's concrete, yes ? Looks a little lean on the mix ... ?

The harnesses we use are the same ones we use for climbing the hills:
https://c2.staticflickr.com/6/5602/15026942014_d22eb1ee32_b.jpg

Here's my setup, for example, as I was digging the fence post holes:
https://c4.staticflickr.com/4/3950/15461715927_30b042e8a8_b.jpg

And, here's what I used when I had to double-line rappel downslope:
https://c4.staticflickr.com/4/3932/15648510152_b903b1b22c_c.jpg

Even so, we've had a few of the typical gotchas, from dropping the
spool of wire (where it rolled a hundred or so feet downhill before
getting wedge under a fallen tree) to the inevitable search for missing
glasses and hammers.

Such is the nature of working in the trees...

Hmmmm ...

Arfa
>

 

[Arfa Daily]

"Danny D." <dannydiamico@gmail.com> wrote in message
news:m2n6ir$c0c$28@dont-email.me...

dpb wrote, on Mon, 27 Oct 2014 21:06:58 -0500:

You also need to consider how much side load this is putting on those
trees and how large they are at that point to handle the lateral load
plus how well their root systems are capable of that additional
continuous load, particularly when the ground gets saturated when it
finally does rain again...

This is a good point, in that sometimes it pours out here, and this is a
steep slope, so the runoff could be great.

We just had a half inch of rain over the weekend, and this is a shot of
the cables and the people on the decking (the dog won't go on the deck):

Animals have a sort of 'sixth sense' about this sort of thing. Perhaps this
should tell you something ... d:-}

Arfa

 

[Danny D.]

Arfa Daily wrote, on Tue, 28 Oct 2014 09:53:11 +0000:

https://c4.staticflickr.com/4/3947/15461051649_0ffee9cb37_b.jpg
Work clothes ?

We're all retired, and, getting a bit complacent, so, we tend
not to own (real) work clothes....

But, we're getting real good at buying army surplus static line!
https://c4.staticflickr.com/8/7474/15627944646_f7aaff11cc_b.jpg

Maybe we should pick up a pair of these Ghillies as fitting
work clothes, since we're always hanging around in the trees:
https://c4.staticflickr.com/4/3943/15465541258_e2d8aa3fd1_b.jpg

 

[John Robertson]

On 10/28/2014, 2:57 AM, Arfa Daily wrote:

"Danny D." <dannydiamico@gmail.com> wrote in message
news:m2n6ir$c0c$28@dont-email.me...
dpb wrote, on Mon, 27 Oct 2014 21:06:58 -0500:

You also need to consider how much side load this is putting on those
trees and how large they are at that point to handle the lateral load
plus how well their root systems are capable of that additional
continuous load, particularly when the ground gets saturated when it
finally does rain again...

This is a good point, in that sometimes it pours out here, and this is a
steep slope, so the runoff could be great.

We just had a half inch of rain over the weekend, and this is a shot of
the cables and the people on the decking (the dog won't go on the deck):

Animals have a sort of 'sixth sense' about this sort of thing. Perhaps
this should tell you something ... d:-}

Arfa

The dog is the only one paying attention to load factors.

John :-#(#

--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

 

[Danny D.]

dpb wrote, on Tue, 28 Oct 2014 09:21:42 -0500:

While it is true that the end that is resting on the ground does have
that support, it's not necessarily so that the remaining load on the
cable is only half; it depends on the actual geometry of the
configuration. It _might_ be half; could be more, could even be less.

Thanks for all the insight.
Below is the owner's response to your concerns.

BTW, I created an animated GIF of the entire process, as I see it,
but I can't get Flickr to show the animations since Flickr turns
an animated GIF into a static JPG.

I'll post the animation separately, if I can figure out how to
preserve the animation, but here is the starting point static JPG:
https://c2.staticflickr.com/6/5605/15466740929_084969faac_z.jpg

Here is where we are right now:
https://c4.staticflickr.com/8/7575/15629669196_d8ed414ac3_z.jpg

And here is the penultimate ending point static JPG:
https://c2.staticflickr.com/6/5600/15466738719_4866bb66b1_z.jpg

Here's the owners response to your valid concerns ...

I wonder if they realize how huge the final redwood tree is?
The tree probably weighs in excess of 2,000 tons, and has a 30 foot
circumference.
The smaller set of redwood trees I would estimate weighs 15 tons.
In a wind of 50 mph, the small tree experiences 200,000 pounds of force
due to the wind.
The idea that 28,000 pounds of tension on a cable is more than it
encounters in a light wind does not seem tenable.
The root structures of both trees routinely handle much larger forces
during a typical day.

A wind blowing at 100 miles per hour generates 25 pounds of force per
square foot.
If that wind were blowing straight down on 800 square feet of deck, we'd
have 20,000 pounds of force.
I consider that unlikely.

Edge-on, we have 67 square feet, or 1,666 pounds of force. But that is
also somewhat unlikely.

Sideways forces will add a little to the cable tension, but will mostly
be taken up pushing against the trees and the support posts.

The deck will weigh in the neighborhood of 5,000 pounds, and has 800
square feet of maximum surface area. Lifting that, requires 6.25 pounds
per square foot, or a wind speed straight up of 50 miles per hour. But
the deck is held down at the ends and in the middle by either trees or
posts, which also limit the amount it can tilt or twist. The surrounding
trees limit the wind considerably.

The assumption that the engineering is "seat of the pants", or that the
mathematics have not been done is incorrect, but the ideas are all good
because I don't want to miss something, by not thinking about it at least.

Let them know that I appreciate their advice!
(Please invite them to lunch on Wednesdays in Redwood City if they're
local.)

 

[Danny D.]

Oren wrote, on Tue, 28 Oct 2014 10:37:43 -0700:

> Those screws are from GRK Fasteners...

The ones with the longer threads were really stinky because
you needed four hands, while suspended on the cable, to
screw them in.

The ones with the shorter threads only take 3 hands.

Here's an animated GIF, I just made, of the suspension bridge...
http://i62.tinypic.com/ieeakx.gif

 

[Danny D.]

Danny D. wrote, on Tue, 28 Oct 2014 20:48:36 +0000:

BTW, I created an animated GIF of the entire process, as I see it, but I
can't get Flickr to show the animations since Flickr turns an animated
GIF into a static JPG.

Flickr turned the animated GIF into a JPG but tinypic seems to keep
it as an animated GIF ...

Here's my rendition, as I understand the plans so far ...
http://i62.tinypic.com/ieeakx.gif

I am omitting the actual building structure, but what you see here
are the following:

1. The starting point, on a steep slope, with a path near the top:
https://c2.staticflickr.com/6/5605/15466740929_084969faac_z.jpg

2. All brown lines are 16-foot long lengths of lumber:
https://c2.staticflickr.com/6/5610/15467815060_5471646329_z.jpg

3. This approximates the "ladder network" you've seen in the photos:
https://c4.staticflickr.com/8/7580/15467423737_a9ec2183b7_z.jpg

4. This was the first (thin) cable that went from tree to tree:
https://c4.staticflickr.com/8/7572/15654210442_007a87f618_z.jpg

5. From that thin cable, we hung two large safety cargo nets:
https://c2.staticflickr.com/6/5614/15467236098_ffe03d5577_z.jpg

6. Then we hung the thick cable, which was initially 250 feet long:
https://c4.staticflickr.com/8/7554/15650701911_a8bc487651_z.jpg

7. We sunk two fenceposts, so that the platform rested on the ground:
https://c2.staticflickr.com/6/5611/15467814730_6b9ae30e5e_z.jpg

8. Then we built & suspended the first 16-foot by 10-foot section:
https://c4.staticflickr.com/8/7583/15653383255_8ab43e6304_z.jpg

9. Yesterday, we hung the second 16-foot-long section which is a
foot or two shy of the smaller redwood pair of trees:
https://c4.staticflickr.com/8/7575/15629669196_d8ed414ac3_z.jpg

10. The plan is to add successive 16-foot sections, one by one:
https://c4.staticflickr.com/4/3955/15654209272_22de5c06a0_z.jpg

11. We keep that up until we finally reach the big redwood tree:
https://c2.staticflickr.com/6/5600/15466738719_4866bb66b1_z.jpg

12. And, finally, we'll add 8'x4' sheets of plywood as a railing:
https://c4.staticflickr.com/8/7467/15653381675_a674bb6d59_z.jpg

After that, we begin to build the actual treehouse, complete with
WiFi, refrigerator, bar, running water, and heating (no kidding).

It will take time, of course, so, I'm not sure if I should continue
to update this thread, but, since we've never done this before, any
and all advice is welcome.

PS: Jeff Liebermann and SMS are both welcome to attend the Internet
WiFI setup party since they both live in the area!
https://c4.staticflickr.com/4/3953/15460990220_5b1f28763d_b.jpg

 

[Oren]

On Mon, 27 Oct 2014 23:46:30 +0000 (UTC), "Danny D."
<dannydiamico@gmail.com> wrote:

https://c4.staticflickr.com/4/3935/15025811753_8de1cc2650_b.jpg

Notice we gave up on the lower screw (the one with the longer thread).

Those screws are from GRK Fasteners...

<http://www.grkfasteners.com/index.php/en/>

Videos on Youtube:

<http://www.youtube.com/user/grkfasteners/videos>

 

[Oren]

On Tue, 28 Oct 2014 20:57:49 +0000 (UTC), "Danny D."
<dannydiamico@gmail.com> wrote:

Oren wrote, on Tue, 28 Oct 2014 10:37:43 -0700:

Those screws are from GRK Fasteners...

The ones with the longer threads were really stinky because
you needed four hands, while suspended on the cable, to
screw them in.

The ones with the shorter threads only take 3 hands.

The GRK screws are self-tapping, self-pulling and self-counter
sinking. From videos they will drive into a wood knot - generally with
just a hand held impact drill/driver.

_Screws that Practically Drive Themselves _

<http://www.youtube.com/watch?v=tWFf4IOuAnI&list=PL1szv0FP8dUthzyAv88t3sQzhxFLWMXRF>

<https://tinyurl.com/mza8hmp>

Here's an animated GIF, I just made, of the suspension bridge...
http://i62.tinypic.com/ieeakx.gif

 

[Oren]

On Tue, 28 Oct 2014 21:18:32 +0000 (UTC), "Danny D."
<dannydiamico@gmail.com> wrote:

Danny D. wrote, on Tue, 28 Oct 2014 20:48:36 +0000:

BTW, I created an animated GIF of the entire process, as I see it, but I
can't get Flickr to show the animations since Flickr turns an animated
GIF into a static JPG.

Flickr turned the animated GIF into a JPG but tinypic seems to keep
it as an animated GIF ...

Tinypic showed it just fine:

<http://tinypic.com/view.php?pic=ieeakx&s=8#.VFAWF2dqE2N>

What software did you use to make it?

 

[Danny D.]

Oren wrote, on Tue, 28 Oct 2014 15:22:29 -0700:

What software did you use to make it?
http://i62.tinypic.com/ieeakx.gif

I drew it, by hand, with Kolourpaint, on Linux, which,
according to Wikipedia, is a Microsoft-Paint like drawing app:
http://en.wikipedia.org/wiki/KolourPaint

After drawing each line, I just saved the file to a new name,
e.g., drawing01.jpg, drawing02.jpg, drawing03.jpg, etc.

Then, I slapped it all together with this Linux command:
$ convert -delay 50 -loop 0 *.jpg animatedplans.gif

That created this:
http://i62.tinypic.com/ieeakx.gif

The "loop 0" just means loop forever; and the delay is something
like 50 milliseconds between images, I think.

I use this method only because it's trivially simple to do,
so, I'm sure there are *better* ways to make animated drawings.

For example, on Windows, I'd just draw using "Paint.NET" or even
Microsoft Paint. Then, I'd slap it together using one of the
programs described here:
How to make animated GIFs, by PC Magazine
http://www.pcmag.com/article2/0,2817,2392701,00.asp

 

[Danny D.]

Danny D. wrote, on Wed, 29 Oct 2014 05:04:53 +0000:

There's almost no way you would have known how absolutely huge the big
redwood tree is downslope.

I found only one picture of the big redwood, but it doesn't show
how massive the trunk is (measured at 30 feet in circumference).
https://c2.staticflickr.com/6/5607/15498557171_df86936bcb_b.jpg

There's actually a person, close to the tree trunk up there, in
the cargo net, setting up the blocks of wood for the cable to go
around (this picture was taken a few weeks ago).