Video: Making a Fixed Ridgeline

**namnat** · 03-09-2013, 21:00

I feel like this is a dumb question, but when measuring ones hammock to get a proper ridgeline length and say it's an 11 foot hammock. Are you measuring from where your suspention is attached to the hammock or when it's all layer out flat?

The reason I ask, I cut out a piece 11 feet long but when have it hemmed and cinched up I loose about a foot in length. So would I take 83% of 11 feet or 10 feet?

**Brute1100** · 03-09-2013, 21:30

Originally Posted by namnat

I feel like this is a dumb question, but when measuring ones hammock to get a proper ridgeline length and say it's an 11 foot hammock. Are you measuring from where your suspention is attached to the hammock or when it's all layer out flat?

The reason I ask, I cut out a piece 11 feet long but when have it hemmed and cinched up I loose about a foot in length. So would I take 83% of 11 feet or 10 feet?

83% of final hammock length... Be as exact as you can be... Also measure from the usable part of the hammock... If you have something past where the hammock can fan out ignore than... Example... If you look at this pic, I measure from where the whoopies are attached not from the end of the fabric...

**namnat** · 03-09-2013, 21:53

Originally Posted by Brute1100

83% of final hammock length... Be as exact as you can be... Also measure from the usable part of the hammock... If you have something past where the hammock can fan out ignore than... Example... If you look at this pic, I measure from where the whoopies are attached not from the end of the fabric...

Thanks Brute! Just finished up my ACU camo hammock. Just waiting on some tree straps.

**HURTHEART** · 03-10-2013, 07:25

Thank you, great job. I had to figure out most of what your video shows clearly, the hard way.

I think a "Sticky" is appropriate.

**TheBrewGuy** · 03-10-2013, 20:38

Originally Posted by namnat

I feel like this is a dumb question, but when measuring ones hammock to get a proper ridgeline length and say it's an 11 foot hammock. Are you measuring from where your suspention is attached to the hammock or when it's all layer out flat?

The reason I ask, I cut out a piece 11 feet long but when have it hemmed and cinched up I loose about a foot in length. So would I take 83% of 11 feet or 10 feet?

I would agree with Brute on this one

**TheBrewGuy** · 03-10-2013, 20:41

Originally Posted by HURTHEART

Thank you, great job. I had to figure out most of what your video shows clearly, the hard way.

I think a "Sticky" is appropriate.

As did I. That's why I thought it would be a good idea to show people. I wish I could've seen it done the easy way before I spent hours figuring it out. Thanks!

**Spinefusion** · 03-10-2016, 00:23

Does anyone have a calculator for the amount of cord needed for different types of loops and slings that you can make with Amsteel blue. My question would be to know how much 7/64 Amsteel blue would be needed to make a dog bone that is exactly 93 inches for a fixed ridge line.
Thanks

**wbJohn** · 09-26-2018, 14:39

I'm a bit confused as there is some "loss" of length to the buries. I took a piece of scrap 7/64 Amsteel and made a two inch locked brummel loop in one end. I measured and marked it at 12, 16, and 20 inches. 20180926_152143.jpg

After splicing a locked brummel with one inch of the loose end trimmed by three strands, I got a length of a bit over 13 1/4 inches. That's 3/4 of an inch shorter than the theoretical 14 inches of line lost to the bury. 20180926_152731.jpg

I'm sure once under load, this length will get a bit longer, but not that much. Does anybody have a way to calculate an allowance for the loss in length from the locked brummel bury?

**cmc4free** · 09-26-2018, 15:12

Originally Posted by wbJohn

I'm a bit confused as there is some "loss" of length to the buries. I took a piece of scrap 7/64 Amsteel and made a two inch locked brummel loop in one end. I measured and marked it at 12, 16, and 20 inches. 20180926_152143.jpg

After splicing a locked brummel with one inch of the loose end trimmed by three strands, I got a length of a bit over 13 1/4 inches. That's 3/4 of an inch shorter than the theoretical 14 inches of line lost to the bury. 20180926_152731.jpg

I'm sure once under load, this length will get a bit longer, but not that much. Does anybody have a way to calculate an allowance for the loss in length from the locked brummel bury?

The outer cordage that the bury gets tucked into is expanded by the part of the cordage that is buried inside it. Just like pushing on one of those finger trap toys, as you push the ends together, the diameter expands. Same principle here. The bury being tucked into the outer part of the splice causes the outer part of the splice to expand and therefore the length shortens.

I definitely don't have a formula, but I typically add about an inch per bury to my final desired length, and I'm usually ok with the resultant length. I personally don't feel the need for millimeter precision. 7/64 Amsteel will shorten more than 2.2 Zing-It, which will shorten more than 1.75 Zing-It.

If you always use the same length bury for a given cord diameter, you could write down observations for how much each bury shortens the theoretical length by. Write this down for each type of cordage you use, and the result should be pretty consistent for whatever given diameter cordage... assuming you always use the same length bury.

**wbJohn** · 09-27-2018, 09:36

Originally Posted by cmc4free

The outer cordage that the bury gets tucked into is expanded by the part of the cordage that is buried inside it. [snip]

If you always use the same length bury for a given cord diameter, you could write down observations for how much each bury shortens the theoretical length by. Write this down for each type of cordage you use, and the result should be pretty consistent for whatever given diameter cordage... assuming you always use the same length bury.

That's a great idea that I had hoped somebody else had already done

I think I might try it with my Zing-it ridgeline on my 12 foot hammock this weekend. I made an adjustable ridgeline for it hoping to dial it in over time and then make a fixed ridgeline for it. What's the use of fiddling with the adjustable ridgeline without knowing the final result of the fixed one. With 7/64 Amsteel, it would be off by 1.5 inches by my simple experiment above. That's a lot considering I'm making very small adjustments on the adjustable RL.

Another thing that occurs to me is that lines do get longer when the weave gets put under load. I know this from my kite flying days. We use Spectra/Dyneema lines (75 to 150 feet long) that need to be exactly the same length for dual and quad line kites. We habitually switch lines around left to right and top to bottom to get them stretched out evenly and nobody in his right mind ever used brand new lines in competition. Between the bury "loss" and the weave settling, the end result could be very different from where the line started.