CHAPTER 37 THE INTERACTION OF SURFACE SHIPS WITH THE THERMAL AND RADIOLOGICAL ENVIRONMENT 17.1 17.1.1. PURPOSE AND SCOPE Introduction Knowledge of the interaction of naval ships with the radiation fields resulting from nuclear water-surface or underwater bursts is important in determining the effects of these fields on the personnel aboard the ships. This chapter will discuss the nature of the thermal and radiological effects resulting from nuclear water-surface or under- water bursts in terms of the modification of the radlation fields by eurface ships, including physical interaction with the ship's structure, up to the point where injury of the crew is involved. Effects on ships' personnel will be considered in Chapter 18. Means of predicting thermal and radiological effects include theoretical calculations and scaling techniques employing data from nuclear tests. It should be noted that only a few underwater bursts and no true water-surface bursts over deep water have occurred; thus data pertinent to the effects of such pursts are limited. A brief qualitative description of the general phenomenology involved, is given next as background for the rest of the chapter. 17.1.2 Description of the Effects of Nuclear Surface and Underwater Bursts When a nuclear weapon is detonated, a large amount of energy is liberated in a very small period of time within a limited quantity of matter. This liberated energy manifests itself in the form of a shock wave, thermal radiation, and nuclear radiation. Extremely high temperatures are produced by the tremendous amount of energy created, and a glowing mass of hot gases called the fireball is formed. A large amount of thermal radiation is emitted by this fireball within the first few seconds after a detonation, and the fireball of a surface burst tends to rise at the rate of several hundred feet per second. For a water-surface burst, a large quantity of water is vaporized by the high temperatures, carried up under the fireball into a cloud, and mixed with the fission products that are formed by the detonation. Nuclear radiations are emitted during the first minute after a deton- ation by the fireball, stem, and cloud. As the water vapor cools and condenses back to droplets, these droplets fall to the surface as