Her keel was laid down in 1944 under a Maritime Commission contract (MC hull 1329) by the Barrett, Hilp & Belair Shipyard in San Francisco, California (Type B7-D1).

Midnight completed conversion for Navy use on 28 March and was assigned to the Service Force, Pacific Fleet.

Early in 1946, she was chosen as one of the support ships for "Operation Crossroads", the atomic bomb tests conducted at Bikini Atoll that summer.

Action on that decision was also deferred, and she was used to house Stockton-Pollack employees building a drydock in Apra Harbor.

The barge, however, remained at Apra Harbor because she was impounded due to a dispute over ownership of the vessel between the Asia Development Corporation and Moellers, Limited, of Hong Kong.