Here's the big brute from the MH Racine "tank" stable.  It's the M44 self propelled howitzer weighing in at around 36 tons.  In one shot on the flat it is seen on the Racine test track.  It was claimed that this machine bearing a 155mm howitzer could be put into action faster than any other piece of field artillery at the time whether they be towed or self propelled.

The other shot shows it hill climbing on the Aberdeen Proving Ground in Maryland.  The specifications when it was designed and built  called for it to climb a 60% slope and fire on a 30% slope.  It was also demonstrated on MH's Racine test track on 12th August 1954.  Amazing that these were being made when "I was a lad"!

John