Excerpts from Operation Hardtack

The awesome force of even small atomic blasts was clearly demonstrated in the first two of six tests shown in this silent montage of films taken during Operation Hardtack I. The tests WAHOO, UMBRELLA, TEAK, QUINCE, ORANGE, and FIG were conducted in the Pacific Proving Ground between May and August 1958. WAHOO (9 kilotons) and UMBRELLA (8 kilotons) were underwater tests conducted near Enewetak Atoll on May 16 and June 8, respectively. Target arrays of ships and submarines were moored nearby to test the effects of the blasts. Each test resulted in spectacular plumes of water rising upwards of 1,000 feet. The radioactive clouds produced by the shots engulfed the target ships. The ships appeared tiny when compared with the giant clouds. The force of the blasts sent violent waves crashing onto the Atoll, leaving debris-strewn beaches. "Are you still there?" was the first radio transmission received at Johnston Island hours after the TEAK thermonuclear test on August 1, 1958. The 3.8 megaton, 77-kilometer-high blast triggered an electromagnetic pulse (EMP) which stopped radio communications throughout that large area of the Pacific. The EMP was so severe that military and civilian aircraft had to be grounded in Hawaii. The TEAK fireball could be seen as far away as Oahu Island, approximately 525 nautical miles from Johnston Island. Eyewitnesses said the colorful display rivaled the "Southern Lights," also referred to as the Aurora Australis. Several scientists viewing the test had to duck into a shelter quickly because an error with the launch vehicle, a Redstone rocket, caused it to detonate directly over Johnston Island instead of 20 miles down range. On August 12, 1958, a second thermonuclear test of 3.8 megatons, ORANGE, was conducted in the Johnston Island area, this time at an altitude of 43 kilometers. It was less spectacular than the TEAK test and had little effect on radio communications and electrical systems in that broad area of the Pacific. The Atomic Energy Commissions University of California Radiation Laboratory and the Department of Defenses Special Weapons Project jointly conducted a cratering experiment on Yvonne Island on Enewetak Atoll. The QUINCE test malfunctioned on August 6, 1958, resulting in a zero yield. This necessitated the execution of the 20-ton FIG test, conducted as a replacement on August 18, 1958.