100 Dahlgren 



evaluation activity for the design and development of these weapons. This was 

 done to simulate, with guns, launching of a bomb from an aircraft at 50,000 

 feet. Guns were modified so that they could accelerate these devices up to the 

 terminal velocity that would be achieved by free-fall. The guns had to accelerate 

 the devices but were not to exceed a certain G-load level because the bombs 

 were not designed for high-G acceleration forces. Several guns were developed 

 that had a multitude of charges. As the device would go down the barrel, these 

 charges would be set off resulting in relatively slow acceleration but achieving 

 the required terminal velocity. These guns were installed in the battery areas at 

 Dahlgren. 



This was after the war? 



This was after World War II but during the development phase [Elsie 

 Project] of atomic weapons. 



They evolved from the Manhattan Project? 



This was a follow-on to the Manhattan Project, but Manhattan, of course, had 

 essentially been dissolved, and the AEC had taken over. However, Dahlgren 

 was the primary test and evaluation facility for these weapons because of our 

 guns, and we could set up big targets. Some of those old targets are still out in 

 the test area — large concrete targets 30 or 40 feet thick. They were too expen- 

 sive to dismantle after they had been built, so they're still out there. The old test 

 butt used to catch the projectiles is also still out there. We had to fire all the 

 projectiles inland because we couldn't afford to lose them out in the water — 

 some of them did have natural uranium components. About the only differ- 

 ences between the final version of the weapon and the version we tested here 

 was that we used either natural uranium or depleted uranium, primarily the 

 U-238 isotope, whereas the weapon designed to function would use enriched 

 elements. Also, we tested a few other little devices which are probably too 

 classified to talk about. We did lose one device out in the water. It bounced out 

 of the target area. We finally had a diving team come in to find it, and we 

 retrieved it. 



We brought all the recovered devices back into the Butler hut which is now 

 the Dahlgren Mail Room [Building 492] and which was at that time a very secret 

 type of facility. We had a big chain-link fence around it, and it was equipped 

 with all sorts of security features and elaborate alarms so that unless you 

 actually knew what you were doing when you went in, you'd trip an alarm. 

 Immediately, marines from the local barracks would surround the place, and 

 an investigation would be started to see what caused the alarm to go off. These 

 were marines armed with machine guns — a spectacular operation at times. 



