  As the Manhattan Project shifted to the theory of implosion assembly in 1944,
plutonium was extremely rare and large uncertainties surrounded the function of
the Gadget. For these reasons, a team within the Manhattan Project began
another ambitious experiment: to confine the effects of detonating two tons of
high explosives and enable the recovery of precious plutonium! No data existed
on the subject, and the team faced numerous challenges as they engineered what
is believed to be the world's first blast-loaded confinement vessel.
