GMH wrote:
I would say operator error also. One time I hitched up and forgot to close the front cargo hatch, so I had to unhitch. The handle on my BW would not stay open due to the pressure of the kingpin on the jaws, so I pinned it open. I pulled ahead, closed the hatch and re-connected. I raised the landing gear and pulled ahead a couple inches so that I could remove the wheel chocks. On my way back to the truck I was horrified to see the handle still pinned in the open position! I got away really lucky and won’t make that mistake ever again!
Your experience is exactly why I say no one does a proper pull test. It is also why I never do one. If you don't know how much throttle you need to use to pull out when your hitch is open you are not doing a proper pull test.
Before anyone jumps on me, I drove semi's for 17 years weighing 120,000 lbs. I have never dropped a trailer. When I got my B&W, I did an actual proper pull test. I hooked up, pinned the jaws open and raised the legs a 1/4" off the blocks then pulled out from under it and let the trailer drop. You would be shocked how much throttle it took to pull away with only the trailer weight holding things together. That is the only way to know if your pull test is good or just a feel good exercise.
When I hook up, I do three separate visual checks. That way even if I get distracted I know I did a visual check. I painted the bottom part of the pin yellow so my wife can see that it is below the jaws and the jaws are closed. She checks me every time before we move.
I hope this never happens to me, but if it does, I know it will be operator error, not equipment error.