Thank you for the heads up. I did witness a guy "jump the pin" already in the yard. He was cranking the trailer up super high and I went over to see if he was ok and super enough he explained it to me. Some older guy said he just wasn't paying attention (on headset).
This got a lot worse when we started getting air ride tractors. With the air ride, when you crank the trailer legs down, you should leave the legs off the ground a good two inches. What you have to remember about the air ride is that it raises the trailer higher than the non-air ride tractors. So, if you crank the legs all of the way down, the trailer is going to be sitting up higher when you pull out from under it than it would with a non-air ride trailer.
This is why drivers are high pinning trailers more now than in the past. It's a conundrum, but the lazy, worthless drivers now, are cranking the legs all of the way down. It doesn't make sense, because you would think a lazy driver would crank the legs down as LITTLE as possible, but it doesn't work that way, for whatever reason. They crank them all the way to the ground.
That leaves the trailer sitting up higher than normal. And the next driver backs up under it, and unless he or she is careful, they will back their fifth wheel under and past the pin. And that ain't no fun getting out of.
The way to prevent this, is when you're backing up, under a trailer, watch the trailer when your fifth wheel is about to hit the trailer. It should raise the trailer when the fifth wheel hits the trailer. If the trailer doesn't move when you get under it, you are wise to stop, get out and check the trailer height. If the fifth wheel isn't touching the trailer, you're gonna have to crank the trailer down until it is making contact with the fifth wheel. This is also when you begin cursing the punk-assed driver before you.
I have to go to bed, but when I get a chance, I'll relay a real good safety demonstration we had here on the best way to back up under the trailers, with these new automatic transmissions, without getting whiplash. Trust me, one of the other drivers here will tell you all about the full-contact boom that happens until you get the hang of a smooth snap to the trailer.