Building a treehouse in the redwood grove of a neighbor (pic

[Danny D.]

Just to update this thread, we completed the 250 feet of steel cabling
today by lashing the two ends together using these cable clamps:
https://c3.staticflickr.com/3/2942/15372056651_7a845164f7_c.jpg

To keep the cables from cutting into the trees, and to allow the trees to
grow outward, we put up a series of these wooden standoff blocks:
https://c3.staticflickr.com/3/2945/15188529430_6294070f9b_b.jpg

You'll notice that we doubled the cables as they wrapped around the trees
so that the strength is always two time 14,000 pounds, at all times:
https://c3.staticflickr.com/3/2944/15188634078_2b3de04150_c.jpg

Here, you can see the two cables, hanging as two catenaries, from which
we will hand the suspension bridge:
https://c3.staticflickr.com/3/2943/15188529300_bbedf3ba0c_c.jpg

We're starting to get used to working in the heights, as you can see by
this photo of my neighbor coming down from disentangling the lines:
https://c4.staticflickr.com/4/3901/15188714847_e77461b64d_c.jpg

As you can imagine, we wear harnesses and we have static lines hanging
from all the trees, as you'd be amazed how many times you need them:
https://c3.staticflickr.com/3/2945/15375216105_9961137c64_b.jpg

In fact, my unenviable job today was to stand at the TOP of this ladder
and position the cables, which I did with two hands on the cables so I
had to be wearing a harness or I would have fallen off in no time:
https://c4.staticflickr.com/4/3870/15188634228_37f45d19e2_b.jpg

I'll let you know when we drill the redwoods to put in the tree bolts,
which will anchor the house; but first, we're working on the suspension
bridge (you can see our cargo netting in some of the pictures above).

Tomorrow we're putting up WiFi on a neighbor's roof, so we wont' be
working on the treehouse until next week.

 

[OFWW]

On Sun, 28 Sep 2014 02:41:13 +0000 (UTC), "Danny D."
<dannydiamico@gmail.com> wrote:

Just to update this thread, we completed the 250 feet of steel cabling
today by lashing the two ends together using these cable clamps:
https://c3.staticflickr.com/3/2942/15372056651_7a845164f7_c.jpg

If you installed these without lock washers I would recommend you
go back up and at least put nylock nuts as safety nuts. Heating
and cooling will cause those nuts to walk off the u-bolts.

To keep the cables from cutting into the trees, and to allow the trees to
grow outward, we put up a series of these wooden standoff blocks:
https://c3.staticflickr.com/3/2945/15188529430_6294070f9b_b.jpg

You'll notice that we doubled the cables as they wrapped around the trees
so that the strength is always two time 14,000 pounds, at all times:
https://c3.staticflickr.com/3/2944/15188634078_2b3de04150_c.jpg

Here, you can see the two cables, hanging as two catenaries, from which
we will hand the suspension bridge:
https://c3.staticflickr.com/3/2943/15188529300_bbedf3ba0c_c.jpg

We're starting to get used to working in the heights, as you can see by
this photo of my neighbor coming down from disentangling the lines:
https://c4.staticflickr.com/4/3901/15188714847_e77461b64d_c.jpg

As you can imagine, we wear harnesses and we have static lines hanging
from all the trees, as you'd be amazed how many times you need them:
https://c3.staticflickr.com/3/2945/15375216105_9961137c64_b.jpg

I hate ladders like these, seen the two by's pull off after a
short while especially if your shouldering a load going up or
down. The rungs should be in notches.

Hope no one or nothing falls.

In fact, my unenviable job today was to stand at the TOP of this ladder
and position the cables, which I did with two hands on the cables so I
had to be wearing a harness or I would have fallen off in no time:
https://c4.staticflickr.com/4/3870/15188634228_37f45d19e2_b.jpg

I'll let you know when we drill the redwoods to put in the tree bolts,
which will anchor the house; but first, we're working on the suspension
bridge (you can see our cargo netting in some of the pictures above).

Tomorrow we're putting up WiFi on a neighbor's roof, so we wont' be
working on the treehouse until next week.

 

[Danny D.]

OFWW wrote, on Sat, 27 Sep 2014 23:55:45 -0700:

If you installed these without lock washers I would recommend you go
back up and at least put nylock nuts as safety nuts. Heating and
cooling will cause those nuts to walk off the u-bolts.

Thank you for that safety suggestion!
That is a good point. Safety is paramount.

This treehouse 50 feet in the air in the redwoods has to outlast us
and it has be safe at all times.

Since we didn't use lock washers on the steel clamps, I will advise
my neighbor and I will snap a picture of the results for you.

You will notice that we doubled up the two ends of the steel cable
as they wrapped around the tree, so that we'd always have two cables
supporting the bridge.

On the big tree, 125 feet away, we will add a wraparound additional
steel cable, so that the middle also has two cables.

Any other safety ideas are welcome, as we're just at the point now
where we can start hanging the suspension bridge from the two steel
catenaries.

For example, you will notice that we followed the rule as shown here:
http://www.pirate4x4.com/tech/billavista/Recovery/dead%20end.jpg

Following that diagram, we put the "saddle" of the clamps on the
"live end" (the mnemonic we used was "don't saddle a dead horse").
http://www.pirate4x4.com/tech/billavista/Recovery/use%20of%20wire%20rope%20clips.jpg

Any other tips are welcome, as we're just now at the stage where
we have the ability to build the 125 foot long bridge starting
about 15 feet up in a pine, and then going straight across a
steep slope through the set of two redwoods, and then on to the
really big redwood 125 feet down the slope.

The treehouse will be in the middle of the bridge.

 

[Danny D.]

OFWW wrote, on Sat, 27 Sep 2014 23:55:45 -0700:

I hate ladders like these, seen the two by's pull off after a
short while especially if your shouldering a load going up or
down. The rungs should be in notches.

This is a good point.

We have so many ladders, most of which are roped end-to-end to the trees
for height, that we just made them as simply as we could.

You can see that we have cargo netting, to allow us to cross from tree to
tree once we climb up the ladders:
https://c4.staticflickr.com/4/3865/15195194790_8fe8c93589_c.jpg

But, we also usually wear safety harnesses and ascenders whenever we work
more than 15 or 20 feet up (which is almost always since it's a steep
slope so what is 15 feet up at the uphill end of the cables is something
like 50 or 70 feet up at the downhill end.

 

[Danny D.]

dpb wrote, on Sun, 28 Sep 2014 13:54:02 -0500:

> I still think the clips should be used as delivered by the manufacturer

They *are* designed for this purpose, are they not?

They didn't come with lock washers.

I'm sure we have nothing against putting them on; but, if they really
needed lock washers, wouldn't they have come with them?

 

[Danny D.]

Dan Coby wrote, on Sun, 28 Sep 2014 12:34:27 -0700:

Are you saying that the tree house will be in the middle of a 125 foot
suspension bridge. How much will the tree house weigh when fully loaded
and do you have any idea of the forces that may be in the cables?

The tree house will be where our cargo net currently is.

That's roughly half way from the uphill pine to the downhill big redwood
(with two little redwoods, side by side, in between).

The steel cables can handle 14,000 pounds each.

That's 28,000 pounds (because we maintain a double cable throughout).

We don't know how much the bridge & treehouse will weigh, but if it's
close to or greater than 28,000 pounds, then we have a problem.

How much do you think a treehouse will weigh?

 

[Danny D.]

Oren wrote, on Sun, 28 Sep 2014 14:21:31 -0700:

> Mentioned twice here. Torque the nuts on the cable clamps to specs.

Yup. 45 foot pounds. Thanks.

I'm relaying all this information to the neighbor as I'm just a helping
hand. I jokingly refer to myself as the "union worker" because I make
jokes about OSHA getting on their case every time I have to climb one
of those ladders!

I do apologize that updates are slow, as I can't snap a picture unless
I'm there, and the treehouse is only worked on during the weekends, and
I'm not always there to help, but I will try to snap pictures as we
progress.

Dunno if I should append all to the same thread, as the way "I" read this
newsgroup is that I only look at the threads from the last day or three.
Dunno how others look at older threads, 'cuz this could take a few months
elapsed time.

 

[Oren]

On Sun, 28 Sep 2014 16:50:02 +0000 (UTC), "Danny D."
<dannydiamico@gmail.com> wrote:

Following that diagram, we put the "saddle" of the clamps on the
"live end" (the mnemonic we used was "don't saddle a dead horse").
http://www.pirate4x4.com/tech/billavista/Recovery/use%20of%20wire%20rope%20clips.jpg

Just curious. Is there a torque spec for those clamps? Or ...

 

[Dan Coby]

On 9/28/2014 9:50 AM, Danny D. wrote:
.... snip

On the big tree, 125 feet away, we will add a wraparound additional
steel cable, so that the middle also has two cables.

.... snip

Any other tips are welcome, as we're just now at the stage where
we have the ability to build the 125 foot long bridge starting
about 15 feet up in a pine, and then going straight across a
steep slope through the set of two redwoods, and then on to the
really big redwood 125 feet down the slope.

The treehouse will be in the middle of the bridge.

Are you saying that the tree house will be in the middle of a 125 foot
suspension bridge. How much will the tree house weigh when fully loaded
and do you have any idea of the forces that may be in the cables?


Dan

 

[Oren]

On Sun, 28 Sep 2014 21:11:55 +0000 (UTC), "Danny D."
<dannydiamico@gmail.com> wrote:

dpb wrote, on Sun, 28 Sep 2014 13:54:02 -0500:

I still think the clips should be used as delivered by the manufacturer

They *are* designed for this purpose, are they not?

They didn't come with lock washers.

I'm sure we have nothing against putting them on; but, if they really
needed lock washers, wouldn't they have come with them?

Mentioned twice here. Torque the nuts on the cable clamps to specs.

I would.

 

[Mike Marlow]

Danny D. wrote:

dpb wrote, on Sun, 28 Sep 2014 13:54:02 -0500:

I still think the clips should be used as delivered by the
manufacturer

They *are* designed for this purpose, are they not?

They didn't come with lock washers.

I'm sure we have nothing against putting them on; but, if they really
needed lock washers, wouldn't they have come with them?

Yes.

--

-Mike-
mmarlowREMOVE@windstream.net

 

[Danny D.]

Dan Coby wrote, on Sun, 28 Sep 2014 20:32:48 -0700:

If you are tensioning the cables for very little sag
then the forces in the cable can be many time the weight
of the tree house.

We "tensioned" the cables, by hand.

What we literally did was put a broomstick through the 60 pound wooden
spool of 250 feet of 3/8" steel cable and we mounted that on two chairs
about 15 feet downhill of a big pine tree.

Then we went uphill to that pine tree at a point about 15 feet off the
ground and then back to the chairs with the spool of wire.

At that point, we tied a rope to the end of the wire, and we walked the
wire downhill a little less than about 100 feet to a big redwood.

At that redwood, we climbed up to the same height as the pine (which,
since it's downhill, is about 40 or so feet up in the air) and we pulled
the rope with the wire cable attached.

Then we pulled the rope which pulled the cable back up the hill back to
the point on the path 15 feet below the pine, where we pulled it tight by
hand, and then clamped the 8 clamps on.

Then, we simply slid the cable around the big redwood and slid it around
the pine, until the cable clamps were symmetric around the pine, as shown
in the last set of pictures.

I won't mention the fact that we accidentally crossed the cables because
we went around the big redwood the wrong way, as that's embarrassing to
mention. Nor will I mention how many times we got hung up in the branches
between trees, necessitating mid-air precarious surgery on the trees.

Given all that, I wouldn't call the tension all that tight. You can see
the sag in the photos. Maybe it sags, oh, I don't know, about 5 to 10
feet maybe?

I do not know what you are planning upon building. That was why I asked
you. If you are talking about the tree houses that we built as kids with
a plywood floor and a few boards and a tar paper roof then only a couple
of hundred pounds. If you are talking about some of the multi story
creations that I have seen on TV then many tons.

I think we're talking just a plywood box, with a deck. I should mention
that there will be anchors on the two little redwoods, so, the treehouse
won't actually be floating on all sides. The bridge *will* be floating
though. It should be fun once it's done and wired for Internet. It has a
great view once you're up in the redwoods.

 

[Dan Coby]

On 9/28/2014 2:18 PM, Danny D. wrote:

Dan Coby wrote, on Sun, 28 Sep 2014 12:34:27 -0700:

Are you saying that the tree house will be in the middle of a 125 foot
suspension bridge. How much will the tree house weigh when fully loaded
and do you have any idea of the forces that may be in the cables?

The tree house will be where our cargo net currently is.

That's roughly half way from the uphill pine to the downhill big redwood
(with two little redwoods, side by side, in between).

The steel cables can handle 14,000 pounds each.

That's 28,000 pounds (because we maintain a double cable throughout).

You also have to consider the geometry of what you are creating. If you
are tensioning the cables for very little sag then the forces in the
cable can be many time the weight of the tree house. Without knowing
exactly what you are creating then I cannot guess. That is why I asked
if you had any ideas of the forces in the cable.

We don't know how much the bridge & treehouse will weigh, but if it's
close to or greater than 28,000 pounds, then we have a problem.

How much do you think a treehouse will weigh?

I do not know what you are planning upon building. That was why I asked
you. If you are talking about the tree houses that we built as kids with
a plywood floor and a few boards and a tar paper roof then only a
couple of hundred pounds. If you are talking about some of the multi
story creations that I have seen on TV then many tons.


Dan

 

[Danny D.]

John Robertson wrote, on Mon, 29 Sep 2014 09:54:57 -0700:

Have you allowed for a windstorm where the trees may be moving in
opposite directions to each other?
Have you allowed for maximum and minimum temperatures?

Only that each cable supports 14,000 pounds!

> You want some sort of shock absorption built in too.

Hmmmmmm.... The cables don't "give" a little when you walk on the bridge
that would be hanging below it?

> May I suggest you find an engineer to look over your design?

The neighbors are all owners of companies and people with graduate
degrees, so, they *are* engineers (of all types). The one having the most
fun with the design is the retired carrier fighter pilot.

> Suspension bridges are close to what you are building

Yes. I'm told the catenary will turn into a parabola once we hang the
bridge off of it. Since the bridge starts uphill about 15 feet above the
trail, it will be fun to just step onto the bridge, at the level of the
trail, and then walk "downhill" level but going higher and higher above
the steeply sloping ground, to get to the two smaller redwoods in the
middle of the span.

At that point, we will be in the "treehouse" which will have a deck and
WiFi and a great open view of the mountains.

Then, if we want, we can walk further to the *big* redwood, which will
have sleeping quarters (hammocks and cargo nets) for the nights we'll
spend there.

It should be fun, once done, and I'll try to keep you guys informed; but
I personally am not designing or building it; I'm just the free help (we
all have Spanish nicknames when we do free labor. I'm "Rodruigo", and my
wife's nom-de-labor is "Marisol", for example).

I keep threatening that I'm gonna call OSHA on them if I fall or if they
don't provide cold soda (the free soda has been warm, to date).

 

[John Robertson]

On 09/28/2014, 2:18 PM, Danny D. wrote:

Dan Coby wrote, on Sun, 28 Sep 2014 12:34:27 -0700:

Are you saying that the tree house will be in the middle of a 125 foot
suspension bridge. How much will the tree house weigh when fully loaded
and do you have any idea of the forces that may be in the cables?

The tree house will be where our cargo net currently is.

That's roughly half way from the uphill pine to the downhill big redwood
(with two little redwoods, side by side, in between).

The steel cables can handle 14,000 pounds each.

That's 28,000 pounds (because we maintain a double cable throughout).

We don't know how much the bridge & treehouse will weigh, but if it's
close to or greater than 28,000 pounds, then we have a problem.

How much do you think a treehouse will weigh?

Have you allowed for a windstorm where the trees may be moving in
opposite directions to each other?

Temperature affects the length of the wire rope, have you allowed for
maximum and minimum temperatures?

You want some sort of shock absorption built in too. Old antennas used
porcelain blocks for joining cables, the porcelain would shatter under
unexpected loads giving the cables a chunk of extra slack to avoid their
collapse by stretching beyond limits.

May I suggest you find an engineer to look over your design? I'm not
one, but can think of a few ways for this to go wrong already including
the clamps failing etc.

Suspension bridges are close to what you are building - read up on the
design criteria for these. Seat of the pants design may give you another
Tacoma bridge...

John :-#)#

PS, it looks like a lot of fun though!

 

[Danny D.]

Oren wrote, on Sun, 28 Sep 2014 10:31:43 -0700:

> Just curious. Is there a torque spec for those clamps? Or ...

I had forwarded this thread to the owner of the treehouse in the redwoods, who replied with the following ...
-----------

People worry too much.

I simply design for 10 times the expected load, and pay the premium.
Trying to finely engineer the solution where torque and special fasteners are important
is a way to save money, and I'd rather spend the money and not waste my time.
I've never seen a malleable cable clamp. Drop forged ones are cheap, and I use more than
normal anyway, not because I think they are needed, but because they help keep the cable
from slipping out of place on the wood block spacers.

The reason for keeping the U-bolt on the dead end of the cable is because the saddle has
a lot more surface area, and thus does not reduce the strength of the cable as much as the
U-bolt does. But they make dual-saddle cable clamps, for those who don't use the over-engineering
approach I do.

Each cable can support 7 tons, so the total weight of treehouse and occupants can be 14 tons.
(Although there will be other supports besides the cable -- one end will rest on the ground, and
another end will be anchored to the tree, and there may be other support cables used just to
make installation and leveling easier.)

If half of the weight is treehouse and the other half is people, we have 7 tons of treehouse
possible (although the actual treehouse will probably weigh less than 1.4 tons fully furnished),
and 7 tons of people (70 people, if they are all 200 pounds). I doubt we will ever have 70 people
in the treehouse -- they'd be shoulder-to-shoulder.

 

[Danny D.]

Oren wrote, on Mon, 29 Sep 2014 16:02:48 -0700:

> It's an insult to call a Mexican a Spaniard!

I guess it's like calling an Asian an Oriental?
Who is insulted when I equate Mexico with Spain anyway?
The Mexicans? Or the Spaniards?

(I don't know these things.)

 

[Danny D.]

Oren wrote, on Mon, 29 Sep 2014 15:20:20 -0700:

Your friend can do as he pleases.
I get the point of over building something.

The good news is that, if the whole thing collapses, *he* gets sued, not
me!

 

[Grant Edwards]

On 2014-09-29, Danny D. <dannydiamico@gmail.com> wrote:

Oren wrote, on Mon, 29 Sep 2014 16:02:48 -0700:

It's an insult to call a Mexican a Spaniard!

I guess it's like calling an Asian an Oriental?

No, that's pretty much correct (if rather dated). "Oriental" literally
means somebody from "the East". Asia is usually defined as "East of
the Urals". Both are somewhat vague terms with meanings that have
changed over the centuries, but Wikipedia says the're pretty much the
equivalent:

The Orient means the East. It is a traditional designation for
anything that belongs to the Eastern world or the Middle East (aka
Near East) or the Far East, in relation to Europe. In English, it is
largely a metonym for, and coterminous with, the Continent of Asia.

Calling a Mexican a Spaniard is like calling somebody from the US
"English" or "British". Rather than being insulted, I think people
are just going to be puzzled over where you've been for the last 250
years.

Who is insulted when I equate Mexico with Spain anyway?
The Mexicans? Or the Spaniards?

Either, both, maybe neither (it probably depends on the crowd).
Regardless of whether it's insulting, it's incorrect.

--
Grant

 

[Danny D.]

G. Ross wrote, on Mon, 29 Sep 2014 20:38:51 -0400:

You keep talking about WiFi. More important is a refrig for the beer.
Why would anyone want WiFi in a treehouse. I would think this would be
a place to escape all that stuff.

Good point, but, this *is* the Silicon Valley environ ...