# Thread: Heavy newbie with a Whoopie question

1. ## Heavy newbie with a Whoopie question

I am excited to break out my new hammock for some camping soon! I am planning on making some Whoopie slings and connect them to a strap.

My question is, I am what you would call a larger individual (300 pounds but dropping, down 25 pounds this year!) and do NOT want to end up sleeping on the ground!

Would the 7/64" Amsteel Blue hold up my heft OK, or should I be going to the 1/8" version?

If the thicker rope is required for the thicker guy, how do you calculate what the burries would be in the 1/8" Amsteel. I would guess that you would need longer burries, but that is just a guess!

2. Amsteel 7/64 has approximately 1600 lb. breaking strength. Most folks use a general safety ratio of 5 to 1, so you're right at it. If you're worried, you can always go up to Amsteel 1/8 which comes in at 2500 lb. breaking strength which would give you an 8 to 1 ratio.

3. Samson Rope who makes Amsteel have some good information on there site here for making whoopies and what not. Amsteel is a 12-strand braid, technically the 7/64 is a 8-strand, and you want to use class II methods.

Your buries are going to be different for each rope diameter in that your fid length is a function of the diameter, 22x I think. This spread sheet will do all the calculations for you and give you all your measurements.

Also keep in mind that a whoopie reduces the rating of the rope to 60%. That leaves you with 960lb, so a factor of 3+. Your call on how big a safety margin you want. Personally at 240 I'm fine with 7/64.

4. I'm at 300 and over in my hammock. 280 with me, 320 with my grand-daughter. 335 with my grandson and grand daugther, 342 with daughter's long hair chihuahua and 382 when Juice, my dog, just has to join. Of course I've had myself, my daughter and my grand-daughter all in at once as well. so that's 280, 135 and 40, all on 7/64th amsteel. Not a worry. It's really strong stuff.

5. Proper splicing retains something like 90% of the breaking strength so you should be fine. I've had 400 lbs on mine before with confidence.

6. Originally Posted by Mouseskowitz
Also keep in mind that a whoopie reduces the rating of the rope to 60%.
That's not correct. KNOTS will derate the breaking strength 50 to 60%, but not splices. According to whoopieslings.com, "The whoopie sling derates the rope by no more than 5% so you can be certain these will give you years of service with no knots to tie."

http://shop.whoopieslings.com/Whoopie-Slings-AWS.htm

7. Originally Posted by Mouseskowitz
Your buries are going to be different for each rope diameter in that your fid length is a function of the diameter, 22x I think. This spread sheet will do all the calculations for you and give you all your measurements.
Thanks for sharing the spreadsheet. That is a very nice tool.

8. Originally Posted by SilvrSurfr
That's not correct. KNOTS will derate the breaking strength 50 to 60%, but not splices. According to whoopieslings.com, "The whoopie sling derates the rope by no more than 5% so you can be certain these will give you years of service with no knots to tie."

http://shop.whoopieslings.com/Whoopie-Slings-AWS.htm

You are correct that eye splices will retain 90-100% of the rated strength. But according to Samson's documentation found at the link I referenced above,"Amsteel and AmSteel-Blue Whoopie Slings have a break strength of 60% of the published average rope break strength." They are good people over at whoopieslings.com but I am more inclined to trust the manufacturer's information.

edit: Here is the direct link.

9. Originally Posted by Mouseskowitz
You are correct that eye splices will retain 90-100% of the rated strength. But according to Samson's documentation found at the link I referenced above,"Amsteel and AmSteel-Blue Whoopie Slings have a break strength of 60% of the published average rope break strength." They are good people over at whoopieslings.com but I am more inclined to trust the manufacturer's information.

edit: Here is the direct link.
You are correct, Knotty wrote an R&D guy at Sampson and got the lowdown on whoopies.https://www.hammockforums.net/forum/...ad.php?t=12319

Some knots, like the figure 8, only lose 20 to 25 % of straight rope strength...some other knots, lose a lot more. Depends on the knot.

10. Originally Posted by outdoorsguy
You are correct, Knotty wrote an R&D guy at Sampson and got the lowdown on whoopies.https://www.hammockforums.net/forum/...ad.php?t=12319

Some knots, like the figure 8, only lose 20 to 25 % of straight rope strength...some other knots, lose a lot more. Depends on the knot.
Thanks for that info. Makes me curious which sizes are on the 60% side and which on the 80%.

The thing that has frustrated me is that I have not been able to find any actual testing data on knots in Amsteel. Everything I find is on nylon kernmantle type ropes. If memory serves, they only need a 3:1 bend vs the 8:1 for Amsteel which means the data is probably not correlative.

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