The Chief. AFSWP. formulated these plans and also a number of separate projects to be conducted on selected development detonations. The Director. Test Division. WET. a staff agency under the Commander, Field Command, AFSWP. was assigned the functions of detailed planning and field implementation of the DOD Weapons Effects Program, Operation Hardtack. The approved military weapon effects test projects in Programs 1 through 6, and 8 and 9 are outlined below and discussed in Chap. 2. Colonel E. A. Pinson, USAF. was assigned as the Technical Director to the DCS/WET. FC, AFSWP. and acted as Deputy Commander, Task Group 7.1, during the operation. The DOD Weapons Effects Programs were organ-~ ized as Task Unit 3 of Task Group 7.1 and commanded by Col K. D. Coleman, USAF. The DOD program participation in Hardtack was of greater magnitude than in any other Program 1. ground shock, and ticipation included Pacific Operation. This program was designed to determine air blast. underunderwater shock parameters and effects. Primary parthe underwater shots, Wahoo and Umbrella; three surface shots, Koa, Cactus. and Fig; and the VHA shot, Yucca. Underwater and air blast pressures from the underwater events will be used as input data to determine safe delivery ranges for ships and aircraft, and to support the target response projects of Program 3. Ground shock measurements from the surface bursts will determine design criteria for "hard" underground structures and missile sites. Air blast data from the VHA shot will provide data to check theoretical estimates of energy partition at high altitudes. Program 2. The objectives of this program were: 1. To determine the gross radiological hazards resulting from underwater bursts. Included were free-field measurements, deck and selected compartment contamination measurements. and measurements of ingestion and inhalation of contamination entering the ship via ventilation and combustion air systems. 2. -To collect neutron energy spectrum data to supplement the presently inadequate knowledge of neutron energy spectra from thermonuclear weap~ ons. Prompt neutron measurements were to be determined from a VHA small yield weapon and from two UHA large yield devices. 3. To measure radiation in the nuclear cloud from selected large yield detonations to obtain better data concerning the contribution of radioactive debris to worldwide contamination. , 4. To determine prompt neutron and gamma radiation and fallout contamination from a subkiloton device. Program 3. This program was designed for determination of the effects underwater bursts on surface and subsurface vessels, and for the study of different types of land structures under various loading conditions. The information obtained by Programs 1 and 3 will be used to aid in formulation of operational doctrine. particularly insofar as delivery ranges and tactics for both surface and subsurface vessels are concerned. The information obtained on the response of ship structures will be used to provide criteria for future designs. Data obtained from various earth-covered flexible arches tested under both long and short duration air blasts, and deep reinforced concrete slabs tested under blast loading, will be used to determine construction criteria for future underground structures and for the study of the response of various types of land structures to air blast from surface detonations. 20