An Unbelievable Set of Declassified Photos Reveal the Preparations Leading Up to the U.S. Nuclear Attacks on Hiroshima and Nagasaki, in August 1945

On August 6th and 9th of 1945, the U.S. atomic bombs were dropped over the Japanese cities of Hiroshima and Nagasaki. These rarely-seen photos give a little look into the other side of the engineering on the first atomic bombs, the mechanical and logistical work that it took to handle, store, transport, and load them; the preparations on the hours leading up to the U.S. nuclear attacks on the two cities.

Notice the “Top Secret” stamp on some of the photos. In the last few photos notice the CRUDE sheet metal work on the casing and fins of “Little Boy” – the bomb that was dropped on Hiroshima.

Notes: A large number of these photos were assembled from the RG-77-BT collection in the Still Photo collection of the National Archives II building in College Park, MD.

Manhattan Project scientists and military personnel gather around the bomb pit, ready to watch the Little Boy bomb being loaded into the Enola Gay.

Little Boy ready to be lifted into the Enola Gay.

Little Boy ready to be loaded into the Enola Gay.

The Enola Gay backs up over the bomb pit.

Little Boy is lifted via a hydraulic lift into the Enola Gay Little Boy is lifted via a hydraulic lift into the Enola Gay.

Little Boy is lifted via a hydraulic lift into the Enola Gay.

A view from underneath the hydraulic lift, in the bomb bay.

Little Boy has been successfully lifted into the bomb bay and is being attached to sway brackets that will keep it secure.

Little Boy in the Enola Gay bomb bay.

Bomb pit on Tinian.

Little Boy, covered by a protective tarp for security reasons Little Boy, covered by a protective tarp for security reasons.

The assembled implosion sphere for Fat Man ready to be placed in the casing.

Sealant is applied via spray gun.

Putty is applied to the forward plate.

Norman Ramsey signing his name on Fat Man.

The Fat Man bomb being towed toward the airfield with an escort.

The sealant has been applied. Note the signatures on the tail assembly and the "bomb" on the worker's shirt.

Fat Man is lowered on to a transport dolly for the trip to the airfield. Note the signatures on the tail assembly.

“A Second Kiss for Hirohito!” Signed by Rear Admiral W.R. Purnell, USN, on the side of Fat Man.

Signatures on Fat Man's tail assembly. You can see the small signature of "W. S. Parsons, USN" or Enola Gay weaponeer Deak Parsons, to the far left.

Preliminary pit alignment.

Fat Man is manually pushed to the bomb pit.

Fat Man's alignment with the bomb pit is checked.

The towing cable is disconnected. Note the MPs keeping guard.

Fat Man is raised on a hydraulic lift.

Once alignment is complete, Fat Man is lowered into the pit.

Fat Man is lowered into the pit.