Aioi Bridge
In 1945, the United States detonated two atomic bombs over the Japanese cities of Hiroshima and Nagasaki, which ended World War II. For this blog, we are going to focus on the bombing of Hiroshima. Specifically, we are going to look at two items in ORAU’s Museum of Radiation and Radioactivity that are tied to the important day that Little Boy fell over Hiroshima. But first, let’s take a moment to set the scene.
According to an article published by the National WWII Museum, at 8:15 a.m. Hiroshima time on August 6, 1945, Little Boy was released from its restraints and the bomb fell from the Enola Gay. The Enola Gay was a Boeing B-29 Superfortress bomber, and it was named after Enola Gay Tibbets, who was the mother of the bomber pilot Colonel Paul W. Tibbets. The bombardier of the flight was Thomas W. Ferebee. As the bomber hovered over the city, Ferebee used the Aioi Bridge, also known as the “T” bridge because from the air it looked like a T, as a target point. The bomb exploded with the force of more than 15,000 tons of TNT directly over a surgical clinic, which was roughly 500 feet from the Aioi Bridge.
Why was the bridge important? That brings us to the first Hiroshima-related item in our museum collection: pieces of reinforcing rod, known as rebar, that came from the explosion of the Aioi Bridge.
According to Paul Frame, Ph.D., who was a health physicist and trainer at ORAU and the founder of the museum collection, the rebar, as well as metal from surrounding buildings, was collected to determine its Cobalt-60 content. Cobalt-60 was produced by the neutrons from the bomb dropping. This information was used to estimate the neutron exposures to the survivors. The rebar was donated to the collection by George Kerr, Ph.D., who worked for over 50 years as a health physicist at Oak Ridge National Laboratory and served as a staff member of ORAU.
Now, let’s turn our attention back to the crew of the Enola Gay. We have already mentioned both the pilot and the bombardier of the mission. The third member of the crew was Theodore J. Van Kirk, and he served as the navigator for the flight.
Another fascinating Hiroshima-related item in our museum’s online collection is an autographed photo of the entire Enola Gay crew. According to Frame, the photograph was purchased sometime in the early 1990s from the Buckeye Aviation Book Company of Reynoldsburg, Ohio. This company sold a variety of items from what they called the "Enola Gay Enterprises and General Paul Tibbets Memorabilia Collection Sales Catalog." In addition to autographed photos, the catalog also included items such as baseball caps, coffee mugs, license plates, and autographed books.
Now that you know about the rebar and autographed photo, be sure to learn more about two other items in ORAU’s Museum of Radiation and Radioactivity that are related to Hiroshima, the roof tile and the wall tile!