The Great Pumpkin Explosion

Monolithic domes – cool. Urban exploration – cool. An exploded, abandoned dome – super cool!

The “Great Pumpkin” is the remains of the Wheeler Grain Company's granary located next to the Elk River, west of Athens, Alabama. It was designed by Dr. Arnold Wilson, a civil engineering professor at Brigham Young University and a pioneer in the monolithic dome industry. The concrete Wheeler dome was built in 1982 with a diameter of 150 ft, a height of 75 ft, and 20 ft dug out below ground level. It could hold one million bushels of grain.

"Before" photo from http://www.monolithic.org/blogs/presidents-sphere/the-west-texas-explosion-an-avoidable-tragedy/photos

In 1988 a fire started (apparently from methane, produced from the grain, not being properly eliminated) and the grain inside the dome burned for several months. It contained 300,000 bushels at the time. The owners knew it might explode and were looking for ways to stop the fire. They had already tried injecting a semi-truck load of carbon dioxide into the dome but that was unsuccessful. They were evaluating where to cut additional holes in the dome when it exploded during the night, waking people four miles away. The top blew off, leaving a 100-ft diameter opening. 

"After" photo from http://www.monolithic.org/blogs/presidents-sphere/the-west-texas-explosion-an-avoidable-tragedy/photos

This event actually demonstrated the structural integrity of domes for containing explosions – the strong lower walls held, allowing the top to act as a relief valve and direct the explosion vertically. The release of pressure then tends to drag the debris back down into the dome. Hardly any concrete landed outside the dome; no lives were lost and there was no other property damaged. The company that built it offered to put the top back on the dome but apparently the owners no longer needed the storage.

The outside of the dome is covered in insulation.

Looking inside the dome