I am hanging a "pot rack" in my kitchen.

Looks kind of like this (http://t0.gstatic.com/images?q=tbn:ANd9GcTsLqnuJA9AwZgmz6j1d4Um6_xy3srDE e8DZ6HJke1X7aXK0OE&t=1&usg=__l5vfgIc5RkZIYZN4zADxnUaCAC4=).

I will have a total of two lengths of wire rope, each one being connected to a hook on the pot rack, going up to the ceiling.

My question.. do I get double the load capacity of the wire rope, since I will have two wires?
i.e. I have 1/16 wire rope, rated at 120lbs. Do I get 240lbs of capacity with two wires?

Yes doubling the wire rope will greatly increase your load, not quite double. How you connect to the ceiling is as about as important as the size of the rope. That 120 lbs, is that working load or breaking load?

Just my idea of a common sense answer:
How much can the rack metal itself hold without buckling, and what about the attachment(s) at the ceiling, and the ceiling itself?
Assuming all those are able to hold 240 lbs, you can probably say that since the ability to hold 120 spreads out along the rack under each wire to a certain extent, then as long as you don't put all the pots at one end, you can say a qualified, yes, it now holds 240 lbs. I think it would take a lot of info about the rack itself to determine how easily it would be to offset the load enough to break one wire. If your rack says it holds 240 lbs, I wouldn't plan on putting that much on it.

ballengerb1 - The capacity is listed as "load limit (lb)", not sure if that is meaningful or not. To connect to the ceiling, I am screwing large "eye hooks" into the support beam. For the wire, I will be creating a loop at each end using "thimble and clamp" sets.

joypulv - I think the pot rack itself probably weighs about 40-50lbs. I figure with my pots and pans, I am just near the 100lb mark, maybe. Probably a bit less. I have never actually weighed my cookware :-). Since I didn't want to put the wire anywhere near it's limit I just wanted to verify my thinking (2 wires = approx twice the load capacity). Thank you for the advice about distributing the load evenly. I will make sure not to hang all my pots on one side!

For a follow up question, I have seen it suggested that one should "spread out" the wires at the top (so they won't run straight up and down, but out at a slight angle) to improve stability. Does this affect the load limit? It seems that the further out they are, the more stress they would be under, but maybe not.

Thank you for the answers!
John

Actually if you spread them out you are going ot lower the actual weight bearing capacity because the stresses will increase. It can be figured out mathematically, but I can't remember the formulas.

Yes, your load capacity will decrease as smoothy told you.

Here's why (I made a simplified sketch)

http://p1cture.me/images/07810197819325380243.png

The smaller the value of \alpha, the larger the value of \theta. And \cos\theta becomes a smaller fraction as \theta becomes large.

In brief, the larger the angle the wire makes with the ceiling, the lower capacity it will support, if you don't want to exceed the load limit of the wire.

Hi Unknown008: if a full load is a bit more on one side of the midpoint than the other, is the load shared? If it is, is there a limit? (Span and weight difference)

The load will be more to one side, just like a see saw, but with wires instead.

http://p1cture.me/images/73717112942847824110.png

Put most at the centre, the wires will share the weight.
Put slightly on one side, one wire will be under more pressure than the other.
Put everything quite spread about and the wires will share the load.