Operation Wigwam

Operation Wigwam involved a single test of the Mark 90 Betty nuclear bomb. It was conducted between Operation Teapot and Operation Redwing on May 14, 1955, about 500 miles southwest of San Diego, California. 6,800 personnel aboard 30 ships were involved in Wigwam. The purpose of Wigwam was to determine the vulnerability of submarines to deeply-detonated nuclear weapons, and to evaluate the feasibility of using such weapons in a combat situation. The task force commander, Admiral John Sylvester, was embarked on the task force flagship USS Mount McKinley (AGC-7).

The test device was suspended by a 2,000 feet (660 meters) cable under a barge. A six-mile tow line connected a fleet tug, the USS Tawasa, and the shot barge itself. Suspended from the tow lines of other tugs were three miniature unmanned submarines named "Squaws", each packed with cameras and telemetry instruments.

The time of detonation was 1300 hrs Pacific Time. The test was carried out without incident, and radiation effects were negligible. The device yielded 30 kilotons. Only three personnel received doses of over 0.5 rems.

The equipment intended for direct measurement of the explosion-generated underwater bubble was not operational at the time of the shot, but based on other measurements, the bubble's maximum radius was calculated as 376 feet, and its pulsation period approximately 2.83 seconds. (See Scientific Director's Report)