View Full Version : rope and trees
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
Which hammock have you bought ?
I wouldn`t recommend hanging your hammock with paracord, I use 5m of this (http://www.profabrics.co.uk/shop/show_product_info.php?id=NTW) stuff at either end..
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. :o along with heavy metal grips..
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 (http://www.profabrics.co.uk/shop/show_product_info.php?id=NTW) 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.
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.
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?
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...:D
This is my hammock setup
http://i222.photobucket.com/albums/dd291/Shewie01/DSC00847.jpg
http://i222.photobucket.com/albums/dd291/Shewie01/DSC00848.jpg
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.
http://i222.photobucket.com/albums/dd291/Shewie01/DSC00850.jpg
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.
http://i222.photobucket.com/albums/dd291/Shewie01/DSC00851.jpg
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
29-01-2009, 19:01
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
Thanks for all your advice chaps.
Just out of interest Rich, that's that bit that's gathering the hammock made of?
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.
http://i222.photobucket.com/albums/dd291/Shewie01/DSC00852.jpg
I guess that makes the weakest link a krab on a loop of 5mm static cord. Now I'm confused :)
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.
Remember the static is in a loop so the strain is halved to each side.
ForgeCorvus
30-01-2009, 20:16
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
30-01-2009, 20:29
I have some HH tree hugger's if you want them.
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
31-01-2009, 00:07
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 ;)
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
31-01-2009, 00:13
Have you got the equations to back that up? I'm a maths tutor, I can handle it :)
have a look here :) (http://www.bushcraftuk.com/forum/showthread.php?t=24199)
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
31-01-2009, 08:54
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 :eek:
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.
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.
I use 20mm webbing for the whole job myself, but feel free to experiment. Just let us know so we can come and watch...:D
What material and what weave do you use?
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,
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. :dunno:
I'll see what I can find. I wonder if there is anything wrong with stretch, to be honest.
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.
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.
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.
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 understood that a little stretch helped with breaking problems, since you don't get a snatch. I've email Woodlore to see what they use on their eco sleep system.
The main point in my mind, is the protection of the tree and the weight is a secondary concern.
The straps are healthier for the trees. Use them and be happy.
The extra weight you carry (isn't much anyway, eh?) is the honor that your back does the trees and you can be proud to carry the weight.
Shambling Shaman
02-02-2009, 18:00
Normally ropes and slings are Dynamic (bit of stretch) static (no/very little stretch)
Still have some tree hugger's if you want them sort of a seat belt material.
How much damage would rope actually do?
I'd never even considered it might be an issue before.
SMarvell - I'd agree with you on the breakage thing. I'd expect the stretch to be beneficial in that respect.
How much damage would rope actually do?
I'd never even considered it might be an issue before.
SMarvell - I'd agree with you on the breakage thing. I'd expect the stretch to be beneficial in that respect.
Obviously, it depends a bit on the tree, but generally a hammock rope holding an adult can do a fair amount of damage -- especially over a couple of nights.
Bark is designed to protect trees, of course, but the long, lateral rubbing of a rope can open the tree up for a variety of unpleasantry because any rub through the bark allows the tender stuff (that the bark protects) to be exposed.
The way I look at is this: if I want the tree to hold me up all night, the least I can do is make sure I do everything possible to protect that tree.
Seems like a fair exchange, no?
dogwood - perfectly fair. :)
I was curious as to whether the need for straps/tape rather than rope was in response to a percieved risk of damage to the tree or a real one.
Sometimes people take precautions that don't need taking, I was wondering if this was one that needed taking or if it was more to do with making straps into a "feature" to add value rather than to actually protect.
I can see the logic in using something kinder to the tree, but was/am curious as to how necessary it actually is.
dogwood - perfectly fair. :)
I can see the logic in using something kinder to the tree, but was/am curious as to how necessary it actually is.
I'm not a botanist, but I've been a hammock camper for about 6 years ( I use a hammock about 1/3 of the time I'm out) and I religiously employ straps and have never seen anything resembling damage on the trees I use.
However, I have seen hammock campers who use ropes cut deeply into the bark -- and in one case when the rope slipped with a big guy in the hammock, essentially debark about a 1 foot by three foot part of the tree. It was ugly.
Ropes and hammocks cause visible damage to trees -- straps don't. We've all seen that trees with bark cuts can have problems, so I say don't do it.
Botanist or not, that sounds pretty conclusive to me.
I'm still hammock-less, but when I do get one... straps it is.
As I said, it was just a wonder as to whether ropes really did damage or just "might" do it. From that post it seems pretty clear.
Thanks for that. :)
Ahahahaha! I've found some 20mm polyester webbing with a 4kN breaking strain. If that doesn't do it, I'll got for the 25mm at 5.2kN.
Any objections? :)
VirusKiller
15-02-2009, 13:15
Ahahahaha! I've found some 20mm polyester webbing with a 4kN breaking strain. If that doesn't do it, I'll got for the 25mm at 5.2kN.
Any objections? :)Can you post links please?
I think this (http://www.shelby.fi/catalog/product_info.php?cPath=141_32&products_id=1127) was it. I didn't end up buying it after all. I found something similar on eBay.
VirusKiller
16-02-2009, 11:11
I found an 18mm tubular polyester webbing option which looks like it has a 9.8kN (1000kg) static strain: http://walkhigh.co.uk/acatalog/Cord_and_Tape.html
However, this is quite over-rated for tarp requirements. I re-did oetzi's calculations from scratch: For a 100kg load, as long as the hammock tapes are at least 20° to the horizontal you have a maximum static strain of about 1.5kN. I reckon a good, flat (non-tubular), lightweight, 20mm polyester webbing rated at 5kN would be a good option. That gives a 3x safety margin.
VirusKiller
16-02-2009, 11:25
A useful comparison of polypropylene and polyester properties: http://www.haywoodproducts.com/webbingstrapping
Note that nylon stretches when wet, so not really an option IMO. Bizarrely though, the tapes supplied with my Nomad Tropical hammock are, indeed, (0.5" tubular) nylon.
VirusKiller
20-02-2009, 18:15
I think this (http://www.shelby.fi/catalog/product_info.php?cPath=141_32&products_id=1127) was it. I didn't end up buying it after all. I found something similar on eBay.I've been in contact with the Finnish company in the link. They sell 20mm and 25mm polyester webbing that's only 18g and 24g per metre respectively. The 25mm is rated at 5.2kN. The 20mm isn't rated, but I can do the maths and reckon that 4kN will be more than adequate for hammock tapes.
Black 20mm and 25mm is in stock, but they only have 25mm in olive green. 20mm olive green (which is ideally what I want) is due in within a month.
Is anyone interested in joining me in a purchase to save on postage costs? If there is enough demand, it's cheaper to buy rolls of the material rather than by the metre.
Might be worth starting a group buy thread.
I think you'll get more takers that way.
As for the damage to the trees:
Obviouly open wounds to the tree is considered a damage, what people tend to forget is that crushing the layer directly underneath the barch is equally as damagaing as making an open wound.
Consider a tree's "infrastructure" like a bundle of straws (you know. straws for drinking)
It is only the outer layer that is alive on a tree. This would then be a single layer of very thin straws.
If you crush or cut open part of this layer, the tree's response is to fill the underlying straws with toxins in the full length of those straws (basically a natural very strong fungicide) to prevent any infections developing, thus cutting of the damaged parts.
The living layer will then start to grow over the damaged parts, nomatter if those parts are open or still under the barch.
No question about it. Line bad, tape better.
EVen better is if you take some decent padding material with you. Could be a coffebean sack for each tying thats under strain.
VirusKiller
21-02-2009, 11:02
Might be worth starting a group buy thread.
I think you'll get more takers that way.Thanks. I think I'll do that.
Shambling Shaman
21-02-2009, 15:52
Thanks. I think I'll do that.
I have some "tree hugger's I can send you if you want? so you can see how HH do the stitching etc.
VirusKiller
23-02-2009, 14:36
I have some "tree hugger's I can send you if you want? so you can see how HH do the stitching etc.Thanks for the offer, but I'm not planning on doing any stitching! I've seen the Ray Mears Eco Sleep System DVD and I've got a fair idea of how I want to set up my hammock.
Cheers,
Joel
VirusKiller
17-05-2009, 18:48
I have started a group buy for lightweight polyester webbing: http://www.bushcraftuk.com/forum/showthread.php?t=41502