Here’s another interesting little bit of Cold War history — the M454 AFAP, an atomic artillery shell:
To be precise, what you’re looking at is an M455 — the training version of the M454 projectile — on display at the National Museum of Nuclear Science & History in Albuquerque, New Mexico.
The M454 was the smallest nuclear artillery round that the U.S. Army ever deployed, primarily assigned to M-109 155mm Self-Propelled Howitzers (a fairly standard artillery piece). Its measurements, from the placard:
Length — 2’10” (86.4 cm)
Diameter — 6.1” (15.5 cm)
Weight — 119.5 lbs (54.2 kg)
In service — 1963-1992
The M454 round carried the W48 warhead, a Pu-239 implosion device with a yield equivalent to that of between 72 and 100 tons of TNT (depending on which source you choose to believe). Some 3,000 of them were produced, the last one being decommissioned in 1996.