Cable strength requirements/load calculator

[spikey78]

Can anyone tell me how to calculate the strength of chain or cable that I would need for a pair of support cables on and extended tail lift on my lorry..
I forgot to concentrate when I was at school!

[anonymous-user]

First calculate the maximum vertical load that can be applied to the farthest end of the tail lift. Worst case is to assume that the heaviest object you're ever going to put on the lift is entirely supported at it's very end (unlikely, but maybe transiently possible) In this case we shall assume that the other end of the lift is not supporting any of that load. And remember to include half the mass of the actual lift "floor" itself.


Now we know the vertical load, we can calculate the load in the angled cables. Using trig, based upon the actual angle of the cables from the vertical.


A few extra points to think about:

1) consider applying a suitable safety factor (say 2x or 3x)
2) consider the load sharing case between the two cables (i.e. could a situation exist where one can take more load than the other (different lengths, un-even loading etc)
3) consider the anchor points for those cables too