There are two ways I know of that it could happen.
1. The kingpin broke off. Yes, I've seen that happen before.
2. The fifthwheel let go. Either something out of adjustment, or something in the fifthwheel broke. I've seen that happen too.
I saw one not too long ago. I came over a hill and saw about 4 escort vehicles and an Anderson tractor parked on the shoulder of the East bound side. He had the jeep hooked to the tractor but no fifth wheel on it. I thought to myself "Gee, thats odd. I wonder where..." And that is when I saw the top of the tower sticking above the shoulder of the road. That is alot of weight on the pin and the fifth wheel.
I had the fifth wheel on my jeep come off one time but the load and trailer were heavy enough so's it only slid about 6 inches. Tore up the road real good though.
Not something I ever thought about before. I've hauled both, oversize and overweight. Used the same tractor and fifth-wheel for all of it. For the equipment that hauls more than 150,000 pounds, the kingpins and fifth-wheels are the same, aren't they? What is the pull rating of the fifth-wheel, and the kingpin? Do we just assume that the tractor can not pull hard enough to break them?
I-10, last week (in either MS or AL) was shut down because of a load with all axles under it. Didn't get a good enough look to see just what it was, but all westbound traffic was being detoured because of it. I saw the load, but do not remember seeing a tractor hooked to it.
Is it possible that for those "SUPER-LOADS", we need to have fift-wheels and kingpins re-designed and beefed up for the load? The only thing I have seen increased is the support against gravity, not the pulling part of it.
It's not normally the fifth wheel or pin that fails it is what they are fixed to. When I lost mine it was the plate that fifth wheel was on came off, bad welding and not large enough bolts.
There is different ratings for fifth wheels available. A common upgrade is a 70 ton fifth wheel. I think that is a pull rating and the standard one is around 35 or 40 tons.
There is different ratings for fifth wheels available. A common upgrade is a 70 ton fifth wheel. I think that is a pull rating and the standard one is around 35 or 40 tons.
And, with this fifth-wheel, are trailers still interchangeable? Or do they also take a larger kingpin?
