2. The coloring of typical UHMWPE ropes is in a surface coating that can wear quickly. I'm not seeing fraying (breaking of fibers) in your photos. I do see strand re-alignment at the bury exits which is normal although your's seems greater than usual. Pulling the adjustable end back on itself to shorten the whoopie will make this worse and is to be avoided.

Not seeing a big problem here...use them.

3. This is great information! Thanks so much for sharing, Gravity! I just finished my first set of Amsteel Blue whoopies and soft shackles (improved shackles with the choked overhand knot).

4. A question, I'm looking at some dyneema line, 2,5mm. It has tear strength listed as 580daN. How do I figure the safe working load from that?

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5. That's 580kg.
Safe working Load (SWL) = break strength / Safety Factor

You choose what safety factor you are happy with. It seems most folk are happy with 5x SF
So for this case, SWL = 580/5 = 116kg
For rescue life loads we use 10x SF.

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6. Thank you! That is what I thought after reading a bit about it, but I was still a bit confused!

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The load isn't shared as you thing. The tension in each rope will be roughly equal if the angles are the same, and that will be equal to the weight. If you are hanging in a perfect triangle with 30° angles. The weight is 100kg X G(9.81) = 981N.

The tension is calculated by mG =T1xSin30 w T2xSin30

If the angles are the same and we module the mass as a point loading T1=T2

Therefore mG=2Tsin30

mG/2 = TSin30

T = (mG/2) / Sin30

T = 490.5 / Sin30 [ Sin30 equal 0.5]

Therefore the total tension in the ropes is 981N or 100kg (220lb) or your starting weight.

If you want to know the tension put on the tree, use cos in place of sin and you'll get the "weight" felt by the tree in the horizontal plane.

If you didn't follow our you think I might have made a mistake, there is a calculator for hammock geometry on the ultimate hang.com

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8. Originally Posted by Ghashul
A question, I'm looking at some dyneema line, 2,5mm. It has tear strength listed as 580daN. How do I figure the safe working load from that?

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daN stands for decanewton. Deca means x10 and newton's if a measure of weigh = mass times acceleration of gravity

580 X 10 = 5800N
Gravity is 9.81m/s.s
So to get a safe mass you divide by g

5800/9.81 = 591kg

1kg =2.2lbs
591kg = 1300lbs.

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9. Or, for an approximation: 1 daN is about 1kg is about 2 lbs.

10. This is a problem i had to get my head around as well.

If you set your hang up at the recomended angle if 30• the amount of force experienced on EACH rope is slightly more than 100% if the total weight suppirted.

Thats YOUE weight PLUS the combined weight of the entire rig supported by the hammock suspension lines.

Some very smart people here have made a hang calculator if you want to calculate this for yourself.

As your hang angle approached 0• the stresses go up dramatically so you need stronger rope.

My personal preference is for SK75 or higher in 3mm or 1/8(which is 3.18mm).

A licjed brummel will also REDUCE the line strength a bit(up to 10% i read) so if you are a dainty wee 130kgs like me then 2.4mm or 7/64 does not give a good safety margin.

I do hang up trees and on rock ledges so i tend to prefer the 10 times life suppoet guidelines.
That means that 3mm is still not good enough for the dangerous hangs but perfectly acceptable for standard liw level hangs with clear ground beliw.

I do have a set of 4mm(1600kgs) dyneema whoppies but the stuff is very bulky and stiff for qyite a long time.

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