Lesson To Be Learned

I had something like this happen once. Backed under a trailer, heard that special sound as the lock bar slams home, tug test held. Same ol' same ol'. Attach hoses/pig tail, pre-trip, landing gear, pull forward and into the lane. Then I heard the trailer drop! Fortunately the trailer was still sitting on the chassis, so it wasn't much to raise it back up.

I thought I did everything right. The tug test should prove the attachment was successful. But I ended up giving the other truck drivers that familiar chuckle about Swift drivers.

I suppose you could try it, but the only times I ever set the trailer brakes is when I'm in a dock or dropping a trailer.

shut down with the trailer under tension. That way it would be more difficult for someone to pull the coupling release arm?

That's an excellent point, and it's true.