Lashed Structures? or (Lashed Structures!)

[Bre]

So this is partly a solicitation of tips (perhaps words of caution) from people who have experience with these, and partly sharing the idea.

So I've been experimenting with lashed structures. I was never in the boy scouts, so while I had some vague ideas that "primitive" (or shipwrecked) peoples in the world do this sort of thing, I think i always assumed it must be some esoteric knowledge passed from generation to generation over the course of an entire adolesence (or knowledge imparted by screen writers of films about shiprwrecked people). But, unless I'm missing something, it seems more like something you can learn from the interweb in a few days (Probably less than a few, but I have to figure in extra time because I'm an idiot. Hopefully my famous last words aren't going to be "hey guys, look what I buil...aaaaahhh".)

I havn't built a full size one yet (getting some full sized materials to really try it out tommorow) but from some close to full size models it seems so incredibly easy, quick, verstile, sturdy, inexpensive*, and fun to build to boot.

(*One caveat to claiming they are inexpensive is that a decent fabric, as far as I know, is always expensive. )

I'm wondering, given how easy and sturdy these things seem to be, how come I don't see them more often? Or maybe I just never noticed that people do it? Is there some reason it's not a good idea?

What I've been learning:
So there are 4 basic lashings (which just means a knot you tie around two poles), apparently most of the structures are based on these fours knots, and from them can be built pretty impressive multi-story structures (though, I'm staying away from weight bearing structures since I'm new to it, just tent):

Square Lashing http://www.animatedknots.com/lashsquare/index.php?LogoImage=LogoGrog.jpg&Website=www.animatedknots.com
Most sturdy, given strong poles and ropes, and a reasonably well thought out design (common sense stuff if you stay simple), a couple of these can safely hold a person: and certainly a shade structure

Diagonal lashing: http://www.animatedknots.com/lashdiagonal/index.php?LogoImage=LogoGrog.jpg&Website=www.animatedknots.com
Used to supplement the structures which have the square lashing or non-weight bearing features.

Shear Lashing: http://www.animatedknots.com/lashshear/ ... dknots.com
Designed to make a "bipod", component of an A frame. A of these and some supplemental structur used to, for example, make a bridge. An A frame tent structure is just can be made with these and a bar crossing a few (as few as two really if the tent is reasonably small)

Tripod Lashing:http://www.animatedknots.com/lashtripod/index.php?LogoImage=LogoGrog.jpg&Website=www.animatedknots.com
Makes a very sturdy tripod structure. Can be used as a reliably sturdy compenent (if properly set up) in all kinds of structures or by itself. (I'm going to build our shower out of this structure, tied down to the playa. )

Round Lashing: http://www.animatedknots.com/lashround/index.php?LogoImage=LogoGrog.jpg&Website=www.animatedknots.com
Used to connect to poles together straight (trade off here between strength and length, but this can be mitigated with appropriate structure)

I found this pdf from the boy scouts really helpful: http://www.pioneeringprojects.org/resources/ebooks/sceng.pdf
Note the "10 minute tower". They claim that a pretty large and sturdy platform could be built in 10 minutes with practice. (After practicng for a couple days I've found the knots can be tied pretty quickly---though it may get more diifcult given awkward positions and angles that might arise when building larger structures).

This one is mostly the same info as above but terse: [url]meritbadge.org/wiki/images/f/fc/When_to_use_knots_lashings.pdf[/url]

[Bob]

....I'm wondering, given how easy and sturdy these things seem to be, how come I don't see them more often? Or maybe I just never noticed that people do it? Is there some reason it's not a good idea? ....

Larnie Fox has done lashed bamboo kites and structures out there.

I've used lashed tripods for a bowling-ball pendulum, and miscellaneous camp structures. Some people use them to hang camp shower buckets or bags. If you use wood poles, make sure you strip all bark and branches first. In the scouts we learned hemp rope works nicely, even better if soaked in water so it tightens up as it dries. Sisal rope is okay if it's not designed to carry heavy loads eg hippies climbing up to see God. Anything tall needs to be staked and/or guyed properly so it doesn't turn turtle. I usually lash the uprights to 3/4" steel form stakes at the base.

Imagine one reason they aren't so common, aside from people's inclination to buy manufactured off-the-shelf crap, is that it takes some ingenuity to make a lashed-pole camp structure relatively dust- and weather-tight. And as you imply, it's somewhat of a lost art.

[delle]

so it doesn't turn turtle.

Heheh. "Turn Turtle".


sorry. i'd never heard this one before.

[theCryptofishist]

It is well known that Andrew Selkirk consulted the internet before building his structure.

[Ugly Dougly]

It is well known that Andrew Selkirk consulted the internet before building his structure.

Eh? The archaelogist?

We built some lashed structures as the core of the Barbarian Obstacle course, but they were not shade structures. I reckon as long as you don't:
- Secure a tarp to such a structure and expect to endure the wind
or
- Allow too many playa monkeys to clamber over it at one time...

Then you should be all right. Some pioneering books/sites have lashed gateways that look like something out of Lord of the Flies.

[Oldguy]

Lashing with wet rawhide can last for centuries. I like braided laundry cord. Coated bailing wire lasts a long time too.

[Bob]

The colorful braided poly stuff they sell for truck rope at the big-box stores works great too, just burn the ends so it doesn't ravel.

[shykat]

The colorful braided poly stuff they sell for truck rope at the big-box stores works great too, just burn the ends so it doesn't ravel.

How strong is that rope, it looks like it has paper in the middle of it . I used some for camping swing for the kids a couple weekends ago and was worried it would snap. It didn't.

[Bob]

The colorful braided poly stuff they sell for truck rope at the big-box stores works great too, just burn the ends so it doesn't ravel.

How strong is that rope, it looks like it has paper in the middle of it . I used some for camping swing for the kids a couple weekends ago and was worried it would snap. It didn't.

Should have a "working load" strength on the product labeling, probably a couple hundred pounds. I wouldn't use a 3/8" line to suspend people (eg for swings), but lashing uses multiple wraps. The fact that it didn't break doesn't mean the line didn't degrade during use.