Command and Control

The segment about the Trinity test site in 1945 opens with a shot of a large item on a big trailer with many wheels, pulled by caterpillar tractors. The thing on the trailer is not an atomic device. It was a large steel vessel of 214 short tons, called "Jumbo", that had been specially built at great cost for the first atomic test ("Trinity"). There had been concerns that the device might fail to produce a nuclear explosion. This would have scattered almost all the plutonium across the desert. The plutonium had been manufactured at great expense in some of the world's largest factories which had been built specifically for that purpose. The initial production had been very slow and expensive. So the decision was made to order "Jumbo" and explode the device inside it, in order to save as much plutonium as possible in case of a fizzle. By the time Jumbo arrived though, plutonium was being produced in quantity and Oppenheimer was confident there would be enough for a second test. It was decided not to use Jumbo but instead, hoist it up a steel tower 800 yards from the world's first atomic explosion, which it survived intact. Jumbo's remains are still at the Trinity site. The visible fractures were incurred in a much later test when a conventional bomb with chemical explosive was set off inside it.