Jumbo

Jumbo was the Manhattan Project's insurance: if the plutonium failed to chain-react, the steel jug would hold the conventional blast and keep the scarce metal from scattering. Babcock & Wilcox built it in Barberton, Ohio, and it came west by special train to a siding at Pope, then twenty-five miles on a 64-wheel trailer. By July the scientists trusted the design, and Jumbo hung in a steel tower about 800 yards out; the panel's 800 feet is too close. In 1946 the Army set off eight 500-pound bombs inside it, which blew off both ends.

What the plaque says

Official Scenic Historic Marker Jumbo This is a fragment from Jumbo, a huge steel vessel designed to contain the explosion of the first nuclear device at the Trinity Site some 35 miles southeast of here on July 16, 1945. Jumbo was 25 feet long, 12 feet in diameter, and weighed 214 tons. Its steel walls were 14 inches thick. Although Jumbo was not used in the tests, it was 800 feet from ground zero at the time and escaped without damage except for a steel superstructure around it which was crumpled by the blast. Jumbo was used in later experiments which resulted in the ends being blown out. This piece of Jumbo is a souvenir of the worlds first nuclear explosion. Dr. Marvin Wilkening an observer in 1945

Where it stands

Worth the stop nearby

• Bosque del Apache National Wildlife Refuge — 17 mi
  A Rio Grande refuge south of Socorro where cranes and geese winter by the tens of thousands on wetlands and fields kept by people, because the river no longer floods to make them.

More markers nearby

• Socorro — steps away
• The Garcia Opera House — steps away
• New Mexico Tech — 0.9 mi
• New Mexico Bureau of Mines and Mineral Resources Museum — 1.1 mi