Dec 16, 2011 at 2:31 pm #1283107
Okay, this ain't SUL at all, but some of us climb and many of us have kids.
My epiphany years ago is to NOT drop the 50- to 70-foot-tall beetle-killed spruce (to protect the house, yard, etc and then erect a pressure-treated 6x6s for the swing set, treehouse, cargo net, second treehouse, crow's nest, suspension bridge, third treehouse, monkey bridge, etc. But to just top the tree at 20-30 feet, limb it, and build the stuff onto the tree trunk.
The latest was when my 7-year-old daughter wanted a rock-climbing-themed birthday party. I topped the dead tree at 28 feet and ripped plywood to 2'x8', painted the plywood, attached some commercial handholds and some cut/sanded hunks of lumber, and lag-bolted them to the tree trunk. Three 8-foot lengths made a 24-foot-high climbing wall. There's a pulley at the top for belaying. Since this photo, I've added a second wall, 120 degrees around the same tree trunk.
It ain't a birthday at our house if the mothers aren't a little bit nervous!Dec 16, 2011 at 3:54 pm #1813010
@jamesdmarcoLocale: Finger Lakes
Looks good. The durabilty of raw spruce is not that great, though. Be prepared to replace it right along…Dec 16, 2011 at 4:11 pm #1813019
>"durabilty of raw spruce"
James: I debated that point quite a bit. Growing up in California, I'd come to think: wood is the ground should be pressure treated or redwood. But I can see standing dead spruce all along Turnagin Arm which died on the next high tide after subsiding 20-30 feet in the 1964 Good Friday quake. If I get 47 years out of these, I'll be happy. Oh, and dead by then too, I suppose.
I think the lack of any termites in the state, the frozen ground for 7 months, and very cool ground even in the summer at 60N account for the very slow decay.
I figure by taking the top 40 feet and all the limbs off, it has vastly less "sail area" than it used to and should last a whole lot longer. That said, we don't sleep in the treehouses when it's blowing 40, gusting 56 mph.Dec 16, 2011 at 5:03 pm #1813041
Don't want to tell you what to do, but 2 observations:
1. That doesn't look like a climbing rope. Maybe reconsider your rope choice?
2. If you replace the pulley at the top with something that doesn't spin it will be a lot easier to belay due to the added friction. Instead of having to hold the climber's whole weight, friction at the top will make the climber seem lighter.Dec 16, 2011 at 5:13 pm #1813046
@mtnbob123Locale: Upstate South Carolina
That way you will not have to worry about it for a long time.Dec 16, 2011 at 10:35 pm #1813149
@joshleavittLocale: Ruta Locura
Cool. Growing up in the early '80s everyone in the nieghborhood had basketball hoops. We had climbing holds bolted to the side of our house. ropes?Dec 17, 2011 at 3:49 am #1813183
@jamesdmarcoLocale: Finger Lakes
Yeah, it is your tree. I don't really know the conditions where you live, so, you might very well be correct. I have seen many dead pines (white pines, spruces, etc) near beaver ponds hold up very well when the dam was "reinforced" by a huge blowdown. Others, have died and dropped in 3-4 years out of the water and in damp forested conditions. Just keep an eye on it, poking with a pencil now and then.
We worked on a three sided climbing wall at Cedarlands BS camp made out of old telephone poles (cedar & creosote dipped.) Yours looks good! Thanks for sharing!Dec 17, 2011 at 4:36 am #1813188
You kids are lucky to have a dad like you. Man, I would have killed for a playset like that when I was a kid. I suppose I'll have to spoil the grandkids once I get some.
DaveDec 17, 2011 at 6:02 am #1813206
"Don't want to tell you what to do, but 2 observations:
1. That doesn't look like a climbing rope. Maybe reconsider your rope choice?
2. If you replace the pulley at the top with something that doesn't spin it will be a lot easier to belay due to the added friction. Instead of having to hold the climber's whole weight, friction at the top will make the climber seem lighter."
Especially if people that are not your own are getting on this thing. if anything happens you'd get sued up the wazoo instantly.
What do you have for an anchor? bolts through plywood is NOT going to cut it. my gym is required to put any anchors or climbing bolts through the steel girders behind our wall. plywood is not strong enough to begin with then gets soft and crappy in the rain over time.
instead of the pulley a few steel carabiners or a big steel locking carabiner would be best.
Also you should bring the climbing rope inside while not in use. At the high ropes course i helped run we strung paracord through at night. Whip it to the end of the climbing rope, pull through carabiners. then when you want to use it. whip again, pull the cord and the rope will go right through.
stored properly it'll last you 5-10 years.Dec 17, 2011 at 12:06 pm #1813292
Brad and Jake: Thanks for yor thoughts. The kern-mantle climbing rope was already on order that day so I used a static line from my SRT caving days for my 47-pound kid to be belayed. Cavers routinely put two or three adults on a static line and it is much easier to climb with a little weight from below. I prefer the flexility of the kern-mantle and haven't been very bothered by the dynamic aspect of it – there's not much stretch with a grader schooler on it and even an adult doesn't stretch it much over 50 feet. I think I remember there being UIAA spec for a lower limit on low-load stretch in dynamic line.
SRT = single-rope technique. How cavers repel into a caver and climb out with ascenders. Needlessly touching the cave damages the cave and is bad form.
As to the top anchor: It's a 1/2 bolt through 16" of spruce. Backed up with a loop through two other such bolts. I'm not worried about that. I agree securing it to the plywood would not have sufficed.
A biner instead of a rescue pulley is an intersting idea. No need for it with kids' light weight. But for an adult belaying a bigger adult, it would allow an easier descent. I've got anchors at the base of adjacent trees for the light-belayer-heavy-climber situation.
IMO, the reason to make it reasonably safe is for the safety of the kids, not for the legal liability. The neighbor's kids sometimes get injuries on my trees or treehouses. My kids have been nicked up on their store-bought playground equipment. This is Alaska, not California and there's pretty strong legistated protections for land owners who let other recreate on their land. It's sort of like growing up in the 1950's: They play outside a few hours a day and some stuff happens. Obviously, we try to avoid injuries, but not at the expense of fun, exercise, and developing their skills and independence. That said, I DO really appreciate everyone's thoughts and double-checking me on the details.
Editted to add: I do pull down the climbing rope after each use by running some 1/4" nylon cord as a pull cord for the next session. And I ran the whole concept past the neighbor, realizing it was potentially an attractive nuisance for his kids. He was all in favor of it and he (runs an industrial manpower company) and I have brainstormed on some self-belaying equipment, but the industrial stuff is mostly too beefy for 50 pound kids.Dec 17, 2011 at 12:29 pm #1813298
The rope in your picture does not look like a climbing style static rope. it looks like a braided rope. either way as long as you are getting a climbing rope that is good.
as for the pulley. it will be MUCH easier to control the belay with a biner or 2 instead of the pulley. the forces are also multiplied by a pulley rather than a biner. Hell even 2 links of 1/2" chain connected by a biner would be better than the pulley.
there should be some sort of redundancy in the system. ie the rope should be connected to the single bolt and the back up bolts somehow. It doesn't matter if it's Alaska or New Jersey. climbing anchor systems are universal and need to be safe. It won't be some kid getting a scratch. it will be broken bones or worse.
i've been rock climbing for 10 years so i'm not just saying this stuff.
post this over on RC.com or Mountain project and see what response you get if you don't believe me.
Edit: also how are you belaying these people? do you have an actual harness and belay device?Dec 17, 2011 at 2:07 pm #1813319
Josh and David: Thank you for your kind words. We try to leverage our free time and 13 acres into interactive time with the kids. I've always included the kids in the planning stages. As they get more capable, it's gotten even better as they can participate in some of the construction, painting, etc.
Something I learned on the first few treehouses is one that is built practically to code is not a lot of fun to play on – there's no sense of doing something edgy. It's just a very solid playhouse, up in a tree, with handrails, ballisters, etc. So now I try to design those play structures that feel edgy and a little risky while overbulding it by a factor of 10 and minimizing the risks should a fall happen.
I remember, as a kid, nailing pieces of plywood way up in a Monterey Pine with a hammer and some 8d nails. In California, no less. Guess my parents would be up on charges nowadays.
This was the cake for the party:
And before others jump all over me: Yes, I realize that the licorce ropes would never hold a leader fall by the little Lego guys. And those Lego helmets aren't UIAA rated. And the smooth, round, chocolate "boulders" are a tripping hazard. And while two people on SRT is fine, it's not appropriate for the rock climbing depicted. And a candle flame should never be so close to a belay line. Etc, etc. So we ate all the evidence.Dec 17, 2011 at 2:29 pm #1813326
Jake: the photo is not of the rock climbing style dynamic rope that is on there now (or rather, stored in the garage), it is a laid rope, not braided. Cavers go back and forth on rope styles but unlike in rock climbing, a little stiffness is a good thing in SRT. And since we dislike the lack of flexibility of an ATC* or figure eight, the spin-inducing aspects of a laid rope doesn't matter when using a rack to descend.
Sorry if I wasn't clear about the redundancy – the rope passes through the pulley AND around a loop of steel cable that links the three anchors and encircles the tree trunk. The rope could be a single point of failure, of course, but not the anchor hardware.
When belaying we wear climbing harnesses and use an ATC or Figure 8. A rock-gym employee brought her super spiffy belay / self-belay / repel wonder-thing and she used it, but I'm more competent with the older gear I know well. The climbers are in child-sized climbing harnesses.
*For completeness: ATCs have a lot of flexibility of rock climbers. And they're lightweight. But I wouldn't want to drop a 400-foot pit in one, much less anything big in Mexico. Racks are big and clunky but they let you dial in the friction, adjust it while on rope, and have so much more surface area for disappating heat.Dec 17, 2011 at 4:27 pm #1813344
@levonjensenLocale: Canadian Rockies
what a great way to spend a birthday partyDec 17, 2011 at 7:47 pm #1813388
Yea, rappelling racks are definitely the way to go for caving, i agree.
i still think a few steel links or biners through the bolt and cable would be better on the rope and belayer than the pulley.
ATC works fine. Fig8 for belaying is not ideal. I use both ATC and Trango Cinch(locking assist style..)
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