SUGGESTED RESEARCHES 



307 



right hand portion of Fig. 11 were based on 

 studies at the Army CHmatic Laboratory. 

 The graph ilkistrates the fall in rectal and 

 skin temperature observed in 50 subjects 

 seated in a cold chamber and clothed in 

 heavy flying clothing. Apparently, under 

 heavily clothed conditions the uniform pro- 

 tection of the skin tends to delay the onset 

 of protective shivering (increased heat pro- 

 duction), and lower body temperatures occur 

 than are seen when men more hghtly clothed 

 are exposed to limited periods of cold stress. 

 Chmatic maps have been prepared which 

 relate the clo unit of insulation to various 

 chmates of the world, and the concept has 

 been generally used by the majority of inves- 

 tigators who have attempted a correlation 

 of scientific information with practical expo- 

 sure problems. 



Comment Relative to Temperature and 



Humidity Conditions in Undersea 



Operations 



The foregoing material is intended to be 

 informative rather than minutely prescrip- 

 tive with reference to principles governing 

 thermal hygiene, since the many circum- 

 stances that limit the achievement of ideal 

 air conditions in undersea operations are 

 well known. A survey of operational experi- 

 ence indicates that air-conditioning systems 

 are absolutely essential for effective undersea 

 operations. Present systems are only mod- 

 erately effective. It is beheved that the re- 

 design of such systems in a manner which 

 would guarantee internal temperatures in the 

 range from 15° to 25°C (with humidities 

 below the saturation point) at any injection 

 temperature would provide a major gain in 

 personnel efficiency and health. 



Experience with ultra-violet irradiation of 

 circulated air as a method of reducing odor 

 and contagion hazards has been inconclusive. 

 Civilian experience indicates that triethylene 

 glycol may have a more efficient sterilizing 

 action. However desirable sterilization and 

 odor removal may be, it appears that the 

 major need in submarines is for equipment 



capable of maintaining the thermal balance 

 of the space within the range indicated, and 

 at humidities substantially below saturation. 



Suggested Researches 



Additional investigations of a basic as well 

 as an applied nature remain to be carried 

 out in order that better planning may be 

 done to improve submarine habitability in 

 respect to temperature and humidity. Basic 

 investigations should include : 



1. Researches upon the analysis of the 

 thermal environment. This should include 

 the development of new instiiiments for the 

 measurement of thermal radiation in the 

 visible and near and far infrared portions of 

 the spectrum. It should be the aim to ar- 

 rive at an evaluation of the operative tem- 

 perature of the environment which is the 

 recognized measure of thermal stress. 



2. Studies of the sensations ehcited in the 

 skin of man by these radiations should be 

 carried out to afford a possible quantitative 

 measure of thermal strain. 



3. The effects of sustained thermal stress 

 and elevated body temperature upon sleep 

 and efficiency in mental and physical work 

 should be studied. Some work has been 

 accomphshed along these lines, but none of 

 it has been carried out under conditions 

 approximating those to be encountered in 

 the submarine. 



Apphed researches should include: 



1. A project for removal of the cork lag- 

 ging from a portion of submarine hull to 

 test the effectiveness of this surface in 

 reducing humidity in an experimental com- 

 partment. These studies should be carried 

 out with forced air circulation and natural 

 convection, and attention should be directed 

 toward the transmission of sound from the 

 compartment into the sea. The purpose of 

 this study would be to provide a silent, 

 effective means of reducing humidity in the 

 living spaces of the submarine. 



2. A job analysis should be made of the 

 cooking aboard a submarine, in order to 

 reduce as far as is practicable the release of 



