Operation Sailor Hat

Operation Sailor Hat was an explosives effects test conducted by the US Navy at Kaho'olawe Island, Hawaii in 1965. They were not nuclear tests, instead employing conventional explosives (i.e. TNT) to simulate the effects of a nuclear blast. The purpose of these three tests was to study the effects of shock and blast of a nuclear explosion on naval vessels. In addition, seismological data, underwater acoustics, radio communications, cratering, air blast effects, cloud growth, fire ball generation, and electromagnetic data were gathered. The former light cruiser USS Atlanta (CL-104), USS England (DLG-22), the guided-missile destroyers USS Cochrane (DDG-21), USS Benjamin Stoddert (DDG-22), USS Dale (DLG-19), USS Towers (DDG-9), and the Canadian Navy's escort destroyer HMCS Fraser all participated in the trial.

Each "Sailor Hat" test consisted of a dome stacked 500-ton charge of TNT high explosive detonated on the shore of Kaho'olawe close to the ships under test and each test saw the USS Atlanta move closer to the explosion. The first test, called Bravo, occurred on February 6 and the second test, called Charlie, occurred on April 16, 1965. The last was codenamed Delta and occurred on June 19, 1965.