Ghost Hammock or Knotty Side Stretch w/mods
I am looking to make a lightweight hammock. I'm 210 lbs, using 1.1 ripstop. I was thinking to make a ghost hammock single layer and now I'm thinking of Knotty's side stretch with mods at the head and feet. I want something light, but it needs to hold my weight and be comfortable? BTW is the side stretch the same as a gathered end hammock?
Light for your weight? Expect shorter life
So long as you distribute stresses, the lightest nylon and polyester fabrics are strong enough to support even a heavy person.
The two issues are: Comfort of the stretching and reduced lifespan of the hammock. Just as ropes have a lifespan which is shortened by repeated loading beyond some elastic threshold, so too with fabrics.
For occasional use? And even occasional repeated use? No problem. For strength of the fabric covert the fabric by weight to the equivalent nylon or polyester rope, matching up weight, and looking up breaking strengths (bs).
For example 1.1oz /sq yd nylon fabric is comparable to 1.1 /3 = 0.35 oz/ft cord = 35oz / 100ft cord, just over 2 lb (1kg). That's pretty heavy rope by hammock-hanging standards, even allowing for lost strength from braiding. Looking up a Samson nylon climbing line, you can find 5/16" / 11m Velocity, a jacketed 5.6lb /100 ft line weighing 5.6lb per 100 feet. It is rated rated at 6000lb breaking strength (bs)
That's about 1000lb of breaking strength per lb of fiber in the rope (or fabric?.) Now, all the fibers in the 35oz of cloth will not contribute to breaking strength from loading in one direction. But, some will, in fact, distribute the load. So, that 1.1oz cloth may have minimum breaking strength, if called on to support you being pulled up the side of cliff, of half that say 1000+ lb.
And long term wear? There's a marked difference between regularly loading fibers @ <10% or less of their breaking strength versus loading them at 30+%. In the latter case, the fibers fatique, and will fail catastrophically, and without warning. So, abrasion faults aside, you can see that heavier fabric will likely be more durable, long term.