This has been a fairly exhaustive discussion on the use of chains.
I have a little bit to add from a TC-er who lives in California and routinely plies the mountains.
When I was towing my jeep on a trailer from west of Reno to Lone Pine, CA one year we had a cold, slippery snow all the way, about 200 miles. It took 8 hours. I used 2 WD (with power lock limited slip) for a while until we hit some significant upgrades. When gravity overcame traction, the high preload limited slip tended to migrate the rear axle toward the low side, whichever that was, so I pulled the lever into 4WD. Now we were in level 2: 4WD with snow tires and pulling a trailer. There were several of 2WD pickups with slick street tires overturned in the ditch along the way. I pulled off the highway down a ramp to find the 7K pound trailer and jeep swinging around to the low side, even with the trailer brakes on. I quickly added more thumb trigger, and then less thumb braking power to the trailer which helped right the consist, but not as much as I was hoping.
We continued down Hwy 395 and came to a dead stop south of Topaz Lake. It was a narrow winding section cut into the hillside along the lake and had some banking of the roadway. This was the demise of someone pulling a RV trailer, even with chains. The only drive axle could not over come the drag of the trailer and gravity, even with chains. Waiting for the road to clear about 2003:
A California Highway Patrol man walked by and looked at our rig. He stopped and said, "Chain 'er up". He said if you tow, even with 4WD and snow tires, you need chains on one drive axle. I did not know this and happily complied. We had a new set of cable chains and I used my 2x4 block under the tire to easily put the chains on. No, they did not wear out, I think because I had them on very tightly with no slop. Once the choke point was cleared, we followed a single axle bob tail truck and trailer: 3 axles total. He had chains on the outside of one set of drive axle and one set on the single axle of the trailer. This what took the time: 10-15 mph for about the next 6 hours. I did observe many unchained dual wheel pickups on this long day and noticed that even in 4WD pulling a hill they were slipping all over. Why? Ground pressure or lack thereof. An abundance of floatation.
Back in the day, I chained up all four of my FJ-40's big, oversized tires with big, welded lug chains I had. As mentioned above it was unstoppable in deep snow. I didn't move very fast, but the rig just kept chewing away at the 3 feet of snow I was trying to breach.
After all this, I still hate the idea of using chains.
Remember that just using single chains on one tire of duals is preferred on pavement because of ground pressure. Ground pressure? Yes, the smaller the footprint of the chain the more pressure is focused and exerted to the ground causing less slippage. I found this out when I chained up my real wide tires. They had less effect and tended to slip more on snowy pavement. Plus they are VERY heavy. I would only use them in dire straights around our abode and certainly not on a trip away from the compound.
So, I guess my recommendation (this is the internet, you know, and everything is true; i love that from the poster above) is to keep the strongest cable chains, pre fit for your rig for one tire per side only, in a bag with a block that will fit between the cross links, and tighteners; be ready and able to install them; and hope you never have to use them. Only on a long winter TC trip in the norselands would I be obliged to take even the cable chains along.
jefe
'01.5 Dodge 2500 4x4, CTD, Qcab, SB, NV5600, 241HD, 4.10's, Dana 70/TruTrac; Dana 80/ TruTrac, Spintec hub conversion, H.D. susp, 315/75R16's on 7.5" and 10" wide steel wheels, Vulcan big line, Warn M15K winch '98 Lance Lite 165s, 8' 6" X-cab, 200w Solar