Chockstone Forum

      Sponsored By
      ROCK
   HARDWARE

Chockstone Photography

Australian Landscape Prints

Chockstone Forum - General Discussion

General Climbing Discussion

Topic Date User

Only a Climber...... 11-Feb-2008 At 9:45:55 PM lacto

Message

Assuming that acouple from the "biggest losers ie 300 kg " were in the hammock , 300 kg is approximately 3 kN load on the system . if the hammock strings were at 30 degrees to the horizontal then the load in each string would be 3 kN , and equally the load on each bolt would be 3kN , that is 4 loads of 3 kN would support the two people .
loads within the system to be carried by the chain or krab is 3kn divided by 2 or 1.5 kN Mild steel has a strength of 340 mPa so the area required to carry 1.5kN is 4.4 sq mm or 2.4 mm diameter chain or crab
actual chain size
4mm area 12.56 sqmm os safety factor of 5.2
5mm 19.6 8.1
6 mm 28.2 11.7

vey few things built have safety factor in excess of 2 The steel work is not the problem but the capacity of the bolt anchors would more likely to be the weak link . Throw a normal person in the hammock and the safety factors are enormous and the consequenses of a fall a few cm to the floor. get a life enjoy the hammock it is safe