Cordage Breaking Strengths

[New man]

Just out of curiosity I notice we are testing strength from end to end, but what about when tying down, we have no test for pressure applied to the middle (as if tying a ute load down)

 

[Aussie Forager CQ]

Wonder how long they last in the wild. If you'll pardon the pun I suppoe it is a piece of string question really. Depending on exposure, width, weather conditions, humidity, job being used on etc.
Very interesting. Just as a comparison, what thicknesses of natural twine (Jute) and or nylon etc would be comparable in a similar knotted test? Just to give some sort of apple with African Artichokes comparison.
Cheers
Bloffy

Yeh mate no doubt it does depend a lot....it also depends on quite a few variables with the natural vs synthetic question as well. I have not done a whole lot of small diameter tests. Test #1 was paracord and it is crazily stronger considering it is with a knot as well! We would have to test a heap more pieces to get a cache of results to be able to do some comparisons. That's the idea though!

Natural fibre has other pros other than strength though....mainly with heat resistance, versatility and cost. Obviously you don't need to go to the shop to get some either!

 

[Aussie Forager CQ]

Just out of curiosity I notice we are testing strength from end to end, but what about when tying down, we have no test for pressure applied to the middle (as if tying a ute load down)

Interesting point mate, however it turns out testing the strength of the material pulling end to end will still be the breaking strength of the material when it's used to tie down a load. The difference is in whether the way the load is tied down will amplify the tension in the material and cause it to break. In general the rope will always break at it's tightest bend (knot) if not, it will break where it is damaged or weaker due to a splice or variable in the material. So its technically the same breaking strength, it's just that maybe the way it's tied down increases the force on it when the load moves around.

It would be great if there was a jig to test the forces when tying down a load......

 

[Lepmeister]

Thanks for all the info in this thread, i have found it great reading.

 

[Bloffy13]

I agree with Lepmeister. It is an interesting thread, if you'll pardon the pun (unintended).
Thanks AF. All I was looking for was some sort of comparison on breaking strains. For instance, 230kg breaking strain doesn't mean a lot to me unless I know that paracord breaks at 500kg and jute at 20kg. Lets me start bracketing the fibres and putting them to proper use if I need to. Although I don't think I would rely on natural cordage to tie down a ute load of stuff :: .
Appreciate you taking the time to test this stuff.
Cheers
Bloffy

 

[Aussie Forager CQ]

Test #18

Maker - AFCQ
Material - QLD Bottle Tree*Brachychiton rupestris
Construction - Reverse twisted Z lay
Average Minimum Diameter Approx. 2mm
Test Configuration - *Eye splice on each end.*

RESULT

Breaking strength - 19kN approx. 20kg


Notes.

Quite a good sample. The cordage was made out of one strip of fibre. No splices.

Test #19

Maker - AFCQ
Material - Banana Stalk Fibre
Construction - Reverse twisted Z lay
Average Minimum Diameter Approx. Just under 1.5mm
Test Configuration - *Eye splice on each end.*

Result

Breaking strength - 10kN approx. 10kg

Notes

No splices in this piece. See below for how I got the fibres if your interested.

This is more or less the same way to process agave leaves.*I peeled back the layers of the stalk until they are white. This one was done nearly a month after the plant was chopped down, it does make it harder for the fibres to separate but goes to show it still can be done.*

Then I clamped down one end on a flat surface.

Then with a straight, right angled tool (I used the back of this machete as the plant was a bit old but hard wood works as well if its fresh) I scraped the flesh off one side of the stalk to reveal the fibres.

Then flipped it over and did the other side. How well this works really hinges on how flat the board is, quality of the scraper, freshness of the material and ofcourse practice.

Gave it a hose

Flipped upside down and did the other end. It can go bad at this stage if fibres get caught for a couple of reasons it's important to keep the fibres all level........ practice is the best way to work out how to manage it.*

Some of the excess. There sometimes can be alot of loss of fibres for the above variables.

 

[Aussie123]

Fantastic demo there.

I love those fibres, its amazing they lasted over a month, but I guess its quite a "wet" plant.

Could you get fibres the full length of a banana tree, or do they come in segments ?

 

[Aussie Forager CQ]

Yeh they are super cool. The water in them is crazy, I had to peel a couple of layers to get to the white stuff but they were still usable as well, you can see the moisture run out as you scrape it down.

I also found that its probably best to stand the stalk up if it's going to be stored, the one above was leaning against a wall inside under the house. I had another that was laying down in a relatively shady spot in the yard and it went a rotten on the side that was touching the ground, some of it was still usable and it was still full of moisture too though.

From the plant I've seen you can get the layers of the stalk off the entire length so i guess the only issue would be processing them. I had a tall plant as well but I cut it in half to make it a bit easier to scrape down in a nice smooth run.

It was actually great to work with some really long fibres!

 

[Aussie Forager CQ]

I had relatively recently heard and had a go of making cordage from the dry layers of stalk on the outside of the stalk. Which worked well too but I had never even heard or thought of doing the above process until I stumbled accross a series of mainly Indian videos with banana fibre. I stumbled accross a few other really good ones in the same sort of field.

http://www.youtube.com/watch?v=ko7p9pMR0fY&feature=youtube_gdata_player

This is one of them. There are quite a few banana fibre videos from the same mob showing processing and some of the crafts they make. Really impressive. The machine they have would make things easier.

 

[Aussie Forager CQ]

Test #20

Maker - AFCQ
Material - Small Leaved Fig, Ficus obliqua
Construction - Reverse twisted Z lay
Average Minimum Diameter - Three tests ranging from approx. 2mm-3mm
Test Configuration - *Eye splice on each end.*

RESULT

Breaking strength

- little one broke at 15kN
- middle one broke at 22kN
- big one broke at 32kN

Notes*

Seems to hold it's own in relation to other fibres tested. A bit of a trend is that for these two ply cordages, for every 1mm diameter we are getting approx *10kg of strength - without a knot.*

More testing on each will start to show which ones are stronger than the rest.

 

[Aussie Forager CQ]

Test #21

Maker - AFCQ
Material - Lomandra longifolia leaf
Construction - Single leaf dried in the sun for approx 1 week
Average Minimum Diameter - Average size leaf - tests conducted on both ends of the leaf
Test Configuration - *Overhand on the bight on each end

Here are two pieces of leaf one is the thick (base) end and the other smaller one the tip.

The small one on the left broke at approximately 15kg.

The big one on the right broke at about 30kg.

Notes

I thought this was quit impressive considering it was not twisted into cordage and just roughly tied as is. Also this breaking strength is with a knot as opposed to spliced like previous cordage tests.


Test #22

Maker - AFCQ
Material - Lomandra longifolia leaf
Construction - Single leaf dried in the sun for approx 1 week
Average Minimum Diameter - Average size leaf*
Test Configuration - *Simulated lashing. 5 wraps (10 strands). Started with the base and finished with half hitches with the tip.

Result

It broke at just over 250kg!

Very impressive! Heaps of potential for lashings. It tied well and did not slip at all during the test.

 

[Dan m]

hey Aussie have you tried a braiding technique with three bundles of fibers? i may test it myself, different types of weaving/braiding and rope making to see which gets the most out of the fibers, some reason i like to think that three stands twisted and braided together would be stronger.

 

[Enigma1]

Absolutely awesome thread AFCQ. I'll send you some Gymnostachys to test. It's my all time favourite.

P.S also added a small piece of Blue Mountains Restio, to try as well.

The Gymnostachys has been dried for about a month.

I'll do some with Gymea Lilly fronds some time as well, and get them off to you, they are quite strong when semi dry too.

 

[Aussie Forager CQ]

hey Aussie have you tried a braiding technique with three bundles of fibers? i may test it myself, different types of weaving/braiding and rope making to see which gets the most out of the fibers, some reason i like to think that three stands twisted and braided together would be stronger.

Dan

Hi mate, I have not done any braided tests at all on the rack but I think that would be very worth while. I have three strand braided green balloon cotton bush fibres and it worked ok in the field. Your dead right about three strands being stronger, especially with twisted cordage.

 

[Aussie Forager CQ]

Absolutely awesome thread AFCQ. I'll send you some Gymnostachys to test. It's my all time favourite.

P.S also added a small piece of Blue Mountains Restio, to try as well.

The Gymnostachys has been dried for about a month.

I'll do some with Gymea Lilly fronds some time as well, and get them off to you, they are quite strong when semi dry too.

Thanks mate! That would be great! I haven't seen or tested either, that will be very interesting! You can either tie or splice your choice of loops in the ends and I can test them as is. Otherwise make them a decent length and I can tie/splice them up here.

 

[Corin]

Mate your Lomandra tests are really impressive! I was very surprised by that.

I have not made cordage since I took on my new job. I really need to get out more....

I am so impressed with the work you are doing though. This stuff is gold! Would you mind if I started to tabulate the results and give them their own sticky thread? would make it easy to see whats been tested, and how, and what we still need to do. Naturally we need to test more of the same materials by different makers and using different methods...

 

[Aussie Forager CQ]

Mate your Lomandra tests are really impressive! I was very surprised by that.

I have not made cordage since I took on my new job. I really need to get out more....

I am so impressed with the work you are doing though. This stuff is gold! Would you mind if I started to tabulate the results and give them their own sticky thread? would make it easy to see whats been tested, and how, and what we still need to do. Naturally we need to test more of the same materials by different makers and using different methods...

Please do mate! I think that is a great idea. That will make it much easier to see where we are at and to compare results. Sounds great.

I need to do more myself, time does get away though. I have a bucket of Hibiscus tileaceus that I am trying to rett at the moment. It will be interesting to see how that turns out.

 

[auscraft]

Great idea Corin also agree this stuff is gold thank AFCQ

 

[Enigma1]

AFCQ, I sent you only short lengths, they were just small samples we show for teaching cordage. I can do some longer stuff, also thicker stuff, if you like. You should have them soon , they were sent Friday.
Gymnostachys is extremely strong, I can't wait to see if that short length is usable.
By the way, all the data for rope making was tested by that Aussie dude in WWIi, forget his name

 

[Aussie Forager CQ]

Enigma, sounds good mate. Looking forward to having a play with them.

What is the story about the Aussie guy that tested rope making stuff? Haven't heard about that before.....