Underwater Nuclear Tests: Operation Hardtack 1958 US Navy Atomic Tests Wahoo & Umbrella (Patreon)

more at http://quickfound.net/

Originally a public domain film, slightly cropped to remove uneven edges, with the aspect ratio corrected, and one-pass brightness-contrast-color correction & mild video noise reduction applied.

The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).

https://en.wikipedia.org/wiki/Operation_Hardtack_I

Wikipedia license: http://creativecommons.org/licenses/by-sa/3.0/

Operation Hardtack I was a series of 35 nuclear tests conducted by the United States from April 28 to August 18 in 1958 at the Pacific Proving Grounds. At the time of testing, the Operation Hardtack I test series included more nuclear detonations than the total of all prior nuclear explosions in the Pacific Ocean. These tests followed the Project 58/58A series, which occurred from 1957 December 6 to 1958, March 14, and preceded the Operation Argus series, which took place in 1958 from August 27 to September 6.

Operation Hardtack I was directed by Joint Task Force 7 (JTF 7). JTF-7 was a collaboration between the military and many civilians, but was structured like a military organization. Its 19,100 personnel were composed of members of the US military, federal civilian employees, as well as workers affiliated with the Department of Defense (DOD) and the Atomic Energy Commission (AEC).

There were three main research directions. The first was the development of new types of nuclear weapons. This was undertaken by detonating experimental devices created by the AEC's Los Alamos Scientific Laboratory and the University of California Radiation Laboratory (UCRL). The DOD performed experiments and tests on these detonations that did not hamper the AEC's research. The second research direction was to examine how underwater explosions affected materiel, especially Navy ships, and was performed by the DOD. The Wahoo test was conducted in the open ocean, whereas Umbrella was in a lagoon. The final avenue of study was to analyze high-altitude nuclear tests to refine the detection of high-altitude nuclear tests and investigate defensive practices for combatting ballistic missiles...

Underwater tests

Underwater tests were conducted to assess the damages to Navy boats and materials. The location for these tests was Enewetak due to the uniformity of the sea bottom in the area. This is critical for the tests so that proper moorings of the target ships can be secured on the sea floor. The underwater explosions create a bubble from the expended energy of the blast. This bubble is due to the vaporization of water that directly absorbs the heat of the blast. This bubble may break the surface depending on how much energy is dispersed and the depth of the nuclear device. The bubble displaces large amounts of water that then collapses in on the bubble after all the energy is expended. The water collapsing in on the cavity is called the "radioactive pool" and has the highest concentration of radioactive material.

Many different projects were put in place to test the two underwater blasts. Wave generation, hydrodynamic variables, and energy released were all studied using multiple sensors...

Wahoo preparation

The nuclear explosion was carried out in open ocean outside of Enewetak. This nuclear test codenamed Wahoo was the first underwater test in the Operation Hardtack series. This test could be considered a continuation of the Wigwam nuclear blast (a deep water nuclear test 500 nautical miles (930 km; 580 mi) off the coast of San Diego). Like its predecessor, the Wahoo shot was a scientific program that studied the effects of an underwater nuclear blast on Navy systems. The nuclear device was positioned 500 feet (150 m) deep in the Pacific Ocean...

Umbrella preparation

The second underwater explosion of the Operation Hardtack series was code-named Umbrella. This test was conducted in the lagoon inside Enewetak. This test could be considered a continuation of underwater test Baker, which was conducted in Bikini Lagoon. Explosions in shallow water can create an underwater crater if close enough to the bottom. The target ships from the Wahoo test were towed into the lagoon to be used again for the Umbrella test. The damage from Wahoo was minor in all cases with the exception of the Moran which required extra refurbishing of the hull. These ships had to be washed down and have the measuring equipment replaced before being put into use. The mooring for Umbrella was considerably easier than for Wahoo due to the location and depth of the lagoon. Information gathered from the Wahoo shot directly affected the Umbrella plans with regard to target array placement and decontamination times. The device was placed with a buoy at a depth of 150 feet (46 m)...