Due to recent concerns expressed in the forums, I e-mailed Airstream to inquire about the safety tow chains they equip their units with. Their answer is below.
Note: Working Load (WLL) is the recommended maximum load which should ever be applied to the chain. Ultimate Breaking Strength is the force at which the chain has broken in factory tests.
I am just passing along the info and not in any way inferring that Airstream is supplying unsafe chains. I'm sure they have done their homework.
Subject: RE: Safety tow chains
Airstream Inc., Safey Chain-All
Chain Manufacturer: Peerless Chain Co.
Working Load: 2900 lbs.
Ultimate Breaking Strength: 11,600 lbs.