Among the hazards posed to storage tanks by thermal radiation are the effects of changes in the mechanical strength of the metal at high temperatures that may lead ultimately to failure. Alarge-scale experimental study has been made of the water cooling requirements for metal surfaces exposed to thermal radiation. A two meter aquare radiation furnace and commercial water spray equipment were used in the study, which included trials on both vertical and inclined target surfaces. Water application rates between 1.4 and 10.4 L/min per square meter and incident heat fluxes up to 70 kW per square meter were employed. The experimental work was supported by a theoretical model of the cooling process. The results indicate that a metal plate, exposed to a nearby radiating source, can be kept below the temperature at which its mechanical properties become impaired as long as a water film, of minimal thickness, can be maintained over it.