| During WWII, the U.S. Army determined that there was | | | | shell was fired a distance of seven miles, was |
| a need for a mobile long range heavy artillery weapon | | | | exploded in the sir and had a yield of 15 kilotons (15,000 |
| to attack strategic targets behind enemy lines - | | | | tons of dynamite/TNT.) |
| communication centers, fortified positions, enemy long | | | | The test was considered a success and a total of |
| range artillery and other high value targets. After the | | | | twenty atomic cannon were built. But over the years, |
| war, it was determined that a heavy artillery weapon | | | | they were slowly retired as their strategic value was |
| that could fire an atomic warhead would be even | | | | greatly diminished. This happened for three reasons. |
| more desirable. This kicked off a dual development | | | | The first was that the world was adverse to atomic |
| effort - designing and building the actual weapon and | | | | weapons used in future conflicts. The second was |
| designing a small enough atomic warhead to be used | | | | more practical. Due to the weight of the cannon - 88 |
| as a shell for the weapon. | | | | tons, it could only travel on high quality roads - |
| In 1952, the cannon was complete. The 280-mm | | | | something that generally did not exist in the conflicts of |
| Atomic Cannon weighted 88 tons and was | | | | the 50s and 60s. The third reason was simple |
| transported by two vehicles capable of moving at | | | | progress. Smaller cannons - 8 inch and 155 mm - were |
| speeds up to 40 miles per hour. The cannon could be | | | | developed that were much more mobile and of more |
| set up and ready to fire in 15 minutes or less. | | | | pracical value in the conflicts of the 50s and 60s. |
| But it wasn't until 1953 that it could be tested with an | | | | Today, there are only four 280-mm cannons still in |
| atomic shell. | | | | existence. They are all retired and located at various |
| On May 25, 1953, during the Operation | | | | locations in the United States. Atomic Annie still exists. |
| Upshot-Knothole test series conducted at the Nevada | | | | It is located at Fort Sill. The other three that exist are |
| Atomic Test Site, the first and last atomic shell was | | | | at the National Atomic Museum in Albuquerque, NM; |
| fired by Atomic Annie as part of the Grable test. The | | | | Fort Riley, Kansas and Aberdeen Proving Ground, MD. |