rope and trees

[Steve M]

The hammock I just bought came with some rather heavy flat rope claiming it was a better grip and kinder to the trees. This is all well and good but it weights a ton.

It seems that most people hang their tarp and hammock with 550 paracord, does that really damage trees?

Can anyone advise me on a good tarp and hammock rope that's light, a good grip and not going to make a mess of the trees I'm using.

Cheers

[Shewie]

Which hammock have you bought ?

I wouldn`t recommend hanging your hammock with paracord, I use 5m of this stuff at either end..

[dwardo]

For your tarp i would say paracord is more than enough. For the hammock tapes are much better as they wont dig into the bark of the tree. Surely they cant be that heavy ?
I use the tapes that hold my canoe on the car roof. along with heavy metal grips..

[Steve M]

Which hammock have you bought ?

Tenth Wonder XL, cos I'm tall. Bit of a pain finding a tarp now, but that's another thread

I wouldn`t recommend hanging your hammock with paracord,

Is that the hammock end or the tree end that causes a problem?

I use 5m of this stuff at either end..

That's 350g of webbing you've got there you know.

They supplied four 4m stretches of something which weights much the same per metre. If I take all four, it's 600g for me. That's more than the hammock, which is only 500g.

How are you finding knotting that webbing?

I was considering a webbing end for the tree and bend it onto a bit of something lighter at the hammock end.

[Wayland]

Webbing is best for the tree but if you want to shed weight you can use a webbing loop to wrap around the tree and then use static cord from that to the hammock.

Paracord is definitely not up to the job and the thicker the cord the less stretch you will get.

[Steve M]

Webbing is best for the tree but if you want to shed weight you can use a webbing loop to wrap around the tree and then use static cord from that to the hammock.

Paracord is definitely not up to the job and the thicker the cord the less stretch you will get.

Not up for the whole job, or not up for the hammock end of a combination job?

[Wayland]

Paracord will handle a small tarp but I've seen a lot of people hit the ground hard because they thought it would be strong enough to support a hammock.

I've even seen a couple of people break 5 or 6mm static cord.

I use 20mm webbing for the whole job myself, but feel free to experiment. Just let us know so we can come and watch...

[Shewie]

This is my hammock setup





I think the webbing tapes are more like 390g with the metal O-rings I sewed in. But the 5m length at either end gives me loads of flexibility.



I snap the Krab onto the hammock cord and metal O-ring, tie the tree end off with an evenk slippery figure of eight knot.



Then I just pull the webbing back through the metal O-ring and put a couple of loops in to tie off. This method is on the Eco System DVD on RMs site.

I use 7mm climbing accessory cord for my tarp ridgeline, and 2mm for the guys.

Hope this helps

[gzornenplat]

Not up for the whole job, or not up for the hammock end of a
combination job?

A chain is as strong as its weakest link and the para cord will be the weakest link.

Most people find that a tight hammock line works best and that puts a greater strain on
the cord.

Take an example - at the upper end, but not overly extreme.

Say you weigh 90 kilos = 14 stone = 200lbs including clothes, sleeping bag and everything
else you have in the hammock.

At each end of the hammock you have 5m of cord leading to the tree and you tie it tight.

When you sit in the hammock it gets half a metre nearer the ground, then the tension on
the cord will be 2000lbs, so you'd need to quadruple the (genuine) 550 paracord, and not
bounce up and down too much :-)

If you are really desperate to keep the weight down, then 4mm polyester-sheathed
dyneema has a breaking strain of about 1250kg and 2 x 5m will cost you about £15. I'm
not sure how much it weighs, but it can't be that much because it floats :-)

Ian

[Steve M]

Thanks for all your advice chaps.

Just out of interest Rich, that's that bit that's gathering the hammock made of?

[Shewie]

Just out of interest Rich, that's that bit that's gathering the hammock made of?

It`s 5mm static cord, it was fitted when I bought it. It also had two heavy metal hooks which I took off.

It`s just a loop with one end passed through and then cinched up.

[Steve M]

I guess that makes the weakest link a krab on a loop of 5mm static cord. Now I'm confused

[Shewie]

The krabs are rated to 23KN so they`re not going anywhere and the cord is plenty strong enough. The only thing that could give on my setup is the stitching on the silk but I can`t see that happening as it`s really well made.

[Wayland]

Remember the static is in a loop so the strain is halved to each side.

[ForgeCorvus]

But, if you pass the krab through the loop you're then loading just one thickness of line....the bit that goes around the metal

I've broken ropes by doing that (heavier ropes and a pair of blocks pulling a stump out in my case), would it not be better to use the loop as a double rope and hitch it on to the krab?

[Shambling Shaman]

I have some HH tree hugger's if you want them.

[Steve M]

If it's 550lb on each end, then the breaking strain is 1100lb (78 stone). That's got to be plenty. I don't really understand the tension got up one order of magnitude gzornenplat. Sure, jumping on it will increase the tension, but not tenfold, surely.

[bikething]

If it's 550lb on each end, then the breaking strain is 1100lb (78 stone). That's got to be plenty. I don't really understand the tension got up one order of magnitude gzornenplat. Sure, jumping on it will increase the tension, but not tenfold, surely.

It's all about triangulation of forces

[Steve M]

It's all about triangulation of forces

Have you got the equations to back that up? I'm a maths tutor, I can handle it

[bikething]

Have you got the equations to back that up? I'm a maths tutor, I can handle it

have a look here

[Steve M]

Cheers for the link. Doesn't that equation mean it started taught horizontally?

Anyway, if people have bust it, they have. And if there is paracord on the hammock, I'd be concerned.

[bikething]

Cheers for the link. Doesn't that equation mean it started taught horizontally?

yes... that's how i string mine up... still drops a foot or 2 in the middle when I'm in it
It is a very simplistic model, but shows the general idea. If you wanted to be deadly accurate you would need to take into account stretch in the fabric/rope, changing pull angles, distribution of weight along the hammock, flex in the trees etc.

[ZDP-189]

Avoid paracord like the plague. Paracord creeps and the knots fuse, even if you quadruple it. It's for securing gear, not people and certainly not people for a long time stretched between two trees.

I hang on spectra/dyneema and even then on 4mm+ lines to lessen creep.

As for trees, well if you hang in the crook of a branch, and tension carefully, it'll be fine, but otherwise, it's nice to use some 1" strapping or pad the line with leaves and twigs or bark.

[Steve M]

I use 20mm webbing for the whole job myself, but feel free to experiment. Just let us know so we can come and watch...

What material and what weave do you use?

[Tadpole]

If it's 550lb on each end, then the breaking strain is 1100lb (78 stone). That's got to be plenty. I don't really understand the tension got up one order of magnitude gzornenplat. Sure, jumping on it will increase the tension, but not tenfold, surely.

Tie a knot in a rope and you reduce its strength, same with if pass it over something. The tests used to determine the breaking strength are carried out under ideal conditions and a using a "static weight". In real conditions and being used for real it's real strength is between 10 and 20 percent of the tested strength,

[Wayland]

What material and what weave do you use?

Not sure, it was from a climbing shop and it has very little stretch in it under load if that helps.

[Steve M]

I'll see what I can find. I wonder if there is anything wrong with stretch, to be honest.

[JoyR]

I can point out here that stretch aint a great thing, my hammock was very securely fastened last night, good bit of clearance between me and the ground, even when in it. As it's the first time I've used it, the webbing provided with it (the same stuff as yours) sloooooowly stretched as I was alseep, to the point my bum was scraping the ground.Rechecked the knots before I decapmed, they were all secure, so must have been stretch.

[BigShot]

Stretch can be good or bad depending on perspective.
If you've just missed a hold while climbing, or vanished down a crevasse, the stretch in the rope is what turns a gut wrenching jolt of a stop into a much more pleasant deceleration.
Of course, not many of us are going to be leaping into a hammock from a lower branch so that kind of stretch wouldn't give much benefit.


I wonder if something with (effectively) zero stretch, let's say a stout chain, would make for a slightly more uncomfortable night. Having never slept in a hammock I don't know, but I imagine that a certain amount of give in the system would make for a smoother ride.


JoyR - what knots had you used? Not to insult you or anything, but could it be that the knots were securely tied and had slipped along the line somehow?
I expect that once the hammock is fully loaded, the lines around the tree would tighten, the knots would tighten and so on - I dunno if that'd add enough length to drop you bum-to-floor, but I imagine that would lead to some degree of sag, even if not as much as you experienced.

[Wayland]

I reckon you're right Joy.

More often than not when you find your hammock on the floor it's either stretch or the trees bending inwards because they are a touch too thin.