quote:
Originally posted by 3FingeredGlove:
To quantify "wicked, wicked tight":
The tension required to hold a single cable and a load which is uniformly distributed along its length is:
T=W*L/(8*h) where
T = tension
W = total weight of cable and netting for one cable
L = span of the cable
h = sag at the center of the cable
So for a single cable, assuming the cable and netting weight 115 lbs, the span is 70 feet, and the cable is allowed to sag 4" (0.3333 feet), the tension is 3019 lbs. If you have three parallel cables, the load on each wall holding the cable anchors would be 9000 lbs. Obviously the cable needs to be more than strong enough to stand the tension.
Too much tension? Allow more sag.
Once you and the construction companay have decided on an acceptable sag, resist the temptation to tighten the cables in order to reduce the sag.
Excellent formula! Since we are getting into the engineering of it, the cable should be sized greater than the calculated value of T. Perhaps 2T.