That reminds me of a trip where I was still training and we were waiting for a crew to bring a coal train off Wolfe Creek Branch here on the Pokey.
The crew had already stopped us,since the branch came into single track to double track,because they were having a tough time pulling the tonnage.
Well one of the brakeman went back to the third unit put it on-line and just like you mentioned ka-boom,but instead of a knuckle they got the draw bar on the rear of the third unit !
Apparently the Engineer didn't notch down before the brakeman placed the isolation switch into run 
We nearly outlawed a hot time freight waiting for them to get things fixed 
!
