Soviet Engineer Equipment. The BTM is a high-speed, bucket-wheel trenching machine mounted on the chassis of the AT-T heavy tracked artillery tractor. This vehicle can dig an 80cm wide and 1.5 meter deep ditch 1,120 meters long in one hour.
Not that you want to do that very often, but it's pretty impressive, still. It was originally designed for trenching in frozen ground, which makes more sense.
Big Trench Maker