Jim and I took a drive up to check out Martinez Lake north of Yuma to see what the fishing might be like. On our drive up there was passed the Yuma Proving Ground. This large atomic cannon is at the entrance to the proving grounds.
The atomic cannon was built in the mid 50's to hurl nuclear shells far enough that they wouldn't kill the peoe who fired them. It is 42 feet long and weighs 42,500 lbs. On May 25, 1953 the Atomic Cannon was tested in Nevada. This resulted in the successful detonation of a 15 kt shell at a range of 7 miles. This was the first and only nuclear shell to be fired from a cannon.
It was just too big to move around easily overseas and had such a limited range that it was obsolete shortly after it was deployed. It was deactivated in 1963.