Ah, I didn't think of it like that. I had read that I needed 1 1/2 times the vehicle weight for the winch but didn't really think about the accessories. Thanks. Although now I will have to go shopping.As FlyFisherman noted, when you double line a winch, you double the effective pulling power. The tension on the line will remain the same, but you'll have two lines pulling. Hence the snatch block and the equipment you secure it with, like the tree strap and shackle, need to be rated for double the pulling power of your winch as a minimum, 24,000 lbs in your case.
Mike