A Shameless Plug

Today’s post is written by Adam Minakowski, an archives technician who works with researchers in College Park.

Opening a box of records in the Textual Research Room at the National Archives at College Park, you expect to find folders stuffed with typed or handwritten documents.  Sure, you’ll sometimes encounter log books, photos, and maps, but these are still paper-based records.  You certainly don’t expect to find an envelope containing wires and objects with a shape and size similar to a car’s cigarette lighter like the ones pictured below.

Yet, these objects did turn up among a researcher’s requested records.  As is often the case, the researcher was very knowledgeable about the records he was looking at and identified these objects as the safety plugs for a Mark VI nuclear weapon.  Obviously, this only increased the fascination with these items.

Plugs like these were inserted into nuclear bombs to interrupt the connections between the bombs’ batteries and firing mechanisms.  By doing so, the plugs prevented the detonation of a nuclear weapon before it was ready to be dropped.  When the time came to use the bomb, a member of the flight crew would remove these green plugs and insert red plugs that reestablished the connection between the battery and firing mechanism.

Safety plugs like these caught the public’s attention back in 2002 when a set of them became the source of controversy and a legal battle.  That year, Morris Jeppson, the man who removed the plugs from the “Little Boy” bomb that was dropped on Hiroshima, offered the plugs he kept from the bomb for sale at auction.  The U.S. Justice Department filed suit to block the sale, claiming the plugs’ design was classified, but courts sided with Jeppson and allowed the sale to go through.

These plugs were part of a different type of bomb than Jeppson’s.  The Mark VI bomb was developed in 1949 and was derived from the “Fat Man” bomb design that was dropped on Nagasaki.  Pictured below, the Mark VI was 127 inches long and 60 inches in diameter, weighing 8,500 pounds.

The safety plugs that our researcher found also don’t have as colorful a history as the ones Jeppson had.  Found among the Sarah Clark Collection (“Central Decimal Correspondence Files, 1919 – 1950.” Record Group 342: Records of U.S. Air Force Commands, Activities, and Organizations, National Archives Identifier 2660904), of research and development project records acquired from Wright-Patterson Air Force Base in Dayton, Ohio, the plugs were part of “Project Kingbee.”  The project, conducted between 1948 and 1951, aimed to test the form and function of equipment used to house a nuclear bomb in the B-50 planes that carried them as well as telemetry equipment.

Although Wright-Patterson supplied most of the equipment for “Project Kingbee,” the records accompanying the safety plugs suggest they were part of bombs tested near Eielson Air Force Base, outside Fairbanks, Alaska, or near Eglin Air Force Base, outside Valparaiso, Florida.  Another aspect of “Project Kingbee” was to test how equipment operated at different temperatures and weather conditions.  This explains why the Alaska tests occurred in March and the Florida tests in July, two inhospitable times of the year in their respective locations.

So even though there’s no great story behind the plugs, it’s at least good to know there are no nuclear weapons sitting around missing their safety plugs.  But it goes to show that you never know what will turn up in the records at the National Archives.  And if you do come across bomb parts during your research, don’t worry:  we’ve checked and there’s no radiation danger from these materials.