The end of 20 billion $ worth Manhattan project and beginning of the atomic era. The device used in the
Trinity test had code name - Gadget. It was an experimental design of the implosion type bomb, used later in
Fat Man. Later on, the same design(obtained via espionage) has been used by USSR in
their first nuclear bomb Joe I.
The core of the gadget was enriched Pu sphere. 9cm in diameter and weighted approximately 6.2kg(13.5lb). The whole device itself was a 1.5m diameter sphere. When everything was ready it took 5 days to finally assemble the Gadget and make it operational. Some of the final tasks were performed at ground Zero.
The first atomic explosion in mankind history was conducted at the Alamagordo Bombing Range in New Mexico. The name of the place, trail called the Jornada del Muerto(Jorney of Death) was apparently somewhat appropriate. The whole test operation was code-named Trinity.
Gadget was detonated on July 16, 1945, 5:29:45 a.m. (Mountain War Time). The explosion yielded 19-22kt, according to various sources. Though later estimates refer to the numbers close to 22kt. THe blast instantly rised the temperature to 10 000 000 degrees. The light was so intense that it was sufficient to cause temporary blindness to an observer 10 miles away. The immense temperature of the blast fuzed te desert sand into glass, which after 50 years still contains the traces of radioactivity.
The explosion resulting crater was 6.5ft(2m) deep and had 260ft(80m) radius. Originally the yield was estimated anywhere between 5-10kt. Since the practical yield was several times more a lot of test equipment and recording devices have been simply destroyed. After the explosion when Gen. Groves was informed about the destroyed equipment, noted: Good at least we know it was that powerful.
Credits - For the color photo of the trinity (trinity2) goes to Jack W. Aeby. He took the only color photo of the Trinity test as a civilian with his own camera & film. Interestingly, this phot often is printed backwards, not sure why, but in this gallery it is shown with correct orientation.