Preparations for the Trinity Test, the world's first detonation of a nuclear weapon, conducted on July 16th 1945 in the Jornada del Muerto in New Mexico; here a huge steel vessel, nicknamed Jumbo, is taken to the test site. Initially commissioned as a blast containment vessel, the bomb was to have been detonated within it's 36cm thick walls. This would allow recovery of the precious plutonium fragments should the nuclear chain reaction fail to sustain itself. However this plan was abandoned due to growing confidence in the device. Jumbo was finally placed about 240 metres from the explosion which it survived unscathed.