I’m certainly not an operator but I do know that you’re going to point the boom at the lift and not pull anything at an angle to the boom. With no outriggers, it’ll tip towards the side that the boom points. So my first question still stands. How do you tip a crane over backwards?

Sorry for continuing the thread drift.

Yeah, that is a puzzle. Does not seem to be any wreckage "behind" the crane.

Maybe they loaded up a heavy lift in "front" of the crane and took a good heavy load on the winches inside the crane and the rigging (cables, chains, shackles) let go releasing the load in front of the crane instantly and the crane "rocked" back away from the load and tipped off the tracks.

Very interesting photos.

Usually they set the center outrigger in the direction of the boom. The end out riggers are set to the rear. A railroad wrecker is rated for slew, that is you can drag cars off to the side with the boom. That is the unique feature of a railroad wrecker. The way to tip a wrecker over backward is to break a sling under a heavy load without setting kickers. Or you can turn the cab to 90 degrees to the track and run the boom alway up without outriggers.