the atomic cannon


Atomic Annie — The M65 Atomic Cannon,

Designed in 1949 by the American Engineer Robert Schwarz, the M65 “Atomic Annie” was inspired by German railway guns used during World War II.  The M65 however, was designed to deliver a nuclear payload to its target.  The gun and carriage itself weighed around 85 tons, was manned by a crew of 5-7, and was transported by two specially designed towing tractors.  At 280mm in caliber and capable of firing a projectile over 20 miles, the gun was certainly powerful enough as a conventional weapon, but the Atomic Annie was certainly no conventional weapon.  In 1953 it was tested for the first time at the Nevada Test Site, where it fired a 15 kiloton nuclear warhead, creating a blast similar in size to the bombs dropped on Hiroshima and Nagasaki.  

After the successful test, 20 M65 cannons were produced for the US Army and deployed in Europe and Korea.  They were almost always in constant motion so the Soviets never knew where they were and could not target them.  While an interesting weapon, the Atomic Annie suffered from limited range, especially after the development of ballistic missiles which could strike a target from thousands of miles away.  The last M65 Atomic Cannon was retired in 1963.  Today only 8 survive, and are displayed in museums across the country.


2B1 Oka & 2A1 Kondensator Nuclear Artillery

Some of the most monstrous SPGs to ever developed surpassed only by the Karl-Gerat, these artillery systems are in the same vein as the US M65 “Atomic Annie” atomic cannon. These were highly impractical weapons and served  as better propaganda than actual nuclear delivery systems. By 1960 they’d been replaced by tactical ballistic missiles such as the 2K6 Luna.

2A1 Kondensator: Pictures 1 through 4. Developed in response to the M65 atomic cannon. Over 65 tons and sporting a 406mm gun with a maximum range of 25 km. Steven J. Zaloga erroneously reports the caliber to be 310 mm. At any rate, a colossal beast developed in 1956. Only four were produced and they were retired by the mid-1960s. 

2B1 Oka: Pictures 5 through 7. Fifty-three tons of Soviet steel and overcompensation. The barrel is over 20 m long and fires a 420 mm, 750 kg projectile, conventional or nuclear, over 45 km. Due to the size of the projectile its practical rate of fire was one round every five minutes. Testing revealed that the recoil was too strong for many components: it damaged drive sprockets, tore the gear-box away from its mountings, etc. and the sheer length and size rendered it incredibly difficult to transport

“The design requirements of the early 1950s resulted in a spate of new nuclear artillery systems in 1956-57. Two self-propelled artillery systems were developed on a common chassis by the Central Artillery Design Bureau: the SU-310 [2B1] mechanized super-heavy gun and the related SU-420 [2A1] mechanized superheavy mortar. Both weapons were paraded in Moscow from 1957 and were crowd pleasers if only for their gargantuan proportions. They did not prove to be tactically successful and their further production was curtailed by Nikita Khrushchev’s personal disapproval.” 

-Steven J. Zaloga and James W. Loop’s book “Soviet Tanks and Combat Vehicles: 1946 to Present,” p. 128, 1987


Evolution of the Maser Cannon. From top to bottom:

  1. Markalite Cannon, The Mysterians (1957)
  2. Atomic Heat Cannon, Battle in Outer Space (1959)
  3. Atomic Heat Ray Gun, Mothra (1961)
  4. A-Cycle Light Ray, Monster Zero (1965)
  5. Type 66 Maser Cannon, War of the Gargantuas (1966)
  6. Hyper Laser Cannon, The Return of Godzilla (1984)
  7. MBT-92, Godzilla vs. Biollante (1989)
  8. ASTOL-MB93, Godzilla vs. Mothra (1992)
  9. DAG-MB96, Godzilla vs. Destoroyah (1995)
  10. Type 90 Maser Cannon, Godzilla Against Mechagodzilla (2002)

Upshot-Knothole Grable was a nuclear weapons test conducted by the United States as part of Operation Upshot-Knothole. The codename Grable was chosen because the letter Grable is phonetic for G, as in “gun”, since the warhead was a gun-type fission weapon. As a shell, or artillery-fired atomic projectile (AFAP), the device was the first of its kind. The test remains the only nuclear artillery shell ever actually fired in the U.S. nuclear weapons test program.  The M65 Atomic Cannon from which it was fired was often called Atomic Annie.

Plenty of potential apocalyptic horrors came out of the Cold War, but the atomic cannon is especially unsettling. This giant gun was able to fire a nuclear weapon with a range of 20 miles, detonating at once an entire enemy platoon.

The gun was developed in the 1950s by the American government over a period of eight years, with a prototype even making its way into the  procession of President Eisenhower’s inauguration. On May 25, 1953, at 8:31 am, over 3,000 military spectators watched from 5,000 yards away as the world’s first atomic artillery round was shot across the desert rock of the Nevada test site.

Nine seconds later, and just over seven miles away, “the shell that could wipe out an entire enemy division” exploded on target with a roaring violence equal to 15,000 tons of TNT,“ throwing debris 500 feet.

After the successful test, 20 of the atomic cannons were produced, each at a cost of $800,000 dollars. They were sent to Europe and Korea, but never saw action. Only eight now survive, including the only one to fire a shot: Atomic Annie at Fort Sill.

The Atomic Cannon:

The Atomic Cannon, at 280 mm, was the largest nuclear capable mobile artillery piece manufactured by the United States. On May 25, 1953, a 280 mm cannon fired an atomic projectile a distance of 7 miles at the Nevada Test Site. Twenty 280 mm cannons were manufactured. None were used in battle.

  •     Operation: Upshot Knothole
  •     Shot Name: Grable
  •     Shot Number: 10
  •     Date: May 25, 1963
  •     Detonation: Airburst
  •     Yield: 15 Kt
  •     Location: Frenchman Flat - Nevada Test Site
  •     Weapon: Mark 9 Gun
  •     Sponsor: Los Alamos Nuclear Laboratory

External image

Within milliseconds of the detonation, the fireball is formed. The smoke trails are visible to the right. The small box at bottom left indicates the area covered on the bottom frame.

External image

This frame shows the precursor which is formed by the blast. The boxed area indicates the area covered on the bottom frame.

External image

This frame is an enlargement of the frame above and shows a train and bus. The device in the background is a very tall tower containing cameras and instruments. The precursor is visible in the upper right of frame.


cavalier-renegade submitted:

Aberdeen Proving Ground outdoor exhibits. I only got there when the indoor ones had already been moved.

1. M65 Atomic Cannon, aka “Atomic Annie”
2 & 3. Jagdtiger with me for size comparison.
4. 16 inch coastal gun M1919 with my dad next to a shell
5. Heuschreke 10, German prototype SPG and weapon carrier with some very realistic camo
6. Sturmpanzer IV, one of four surviving and probably in the worst shape.
7 & 8. MBT-70
9. M1 120mm super-heavy AA. Nicknamed “Stratosphere Gun”

Man, what I’d give to visit a place like this.

Thanks a lot for the submission, it’s awesome!