We trained used a 50 foot lanyard (rope) to fire the Howitzer when loaded with a nuclear shell. You dig a fox-hole to protect yourself first. From that fox-hole, you then pull the lanyard and watch the howitzer destroy itself. The nuclear artillery shell goes down-range, and the tube will exit in the opposite direction.
For obvious reasons, you can only fire one nuclear artillery shell per howitzer.
With 6 Howitzers per Field Artillery Battery, that would make the Russians think twice.
I was on a SWAT team in germany also but from 87 to 89. I hate to see them go away but I guess it was bound to happen. I remember carrying the training round up the four floors worth of stairs daily to our attic classroom in our old german barracks at Schweinfurt. Wonder if any of the training models are left, wouldn't mind having one as a keepsake.