GASES IN SUBMARINES 



271 



relatively little. For example, if a man with 

 a high temperature could possibly swallow 

 a liter of ice water, it would abstract 40 calor- 

 ies, enough to lower his temperature only 

 f°C. This same water vaporized from 

 his skin would abstract 585 calories. 



The humidity of the air can be measured 

 accurately by wet and dry bulb ther- 



Gases in Submarines 

 Table A is taken from an article^ on 

 submarine ventilation published in 1928. 

 In this article it was estimated that under 

 ordinary conditions each man in the sub- 

 marine produces 0.75 cubic feet CO2 and 

 consumes 0.9 cubic foot O2 per hour. Know- 

 ing the total air capacity of the submarine 



TABLE A 



Important Gases Occurring in Submarines 



" The table 38-215 in Bureau of Ships Manual gives the following figures for dangerous concentrations : 

 O2 — Less than 12-7 percent at 29.92 in. Hg. Pure O2 at pressures of 3-4 atmospheres may cause 

 trouble if breathed for an extended period of time (C. K. Drinker, verbal communication says 

 one hour). 

 H2 — mixtures 8-74 percent in air explosive or 8-94 percent in O2. 

 CI2 — 0.0004 percent for § hour, 0.004 percent for a few minutes. 

 AsHs — 0.003 percent, slight symptoms after several hours exposure, 0.005 percent dangerous for one 



hour exposure, 0.025 percent fatal in 20 min. 

 CO — 0.01 percent if breathed for several hours, 0.15 percent if breathed for half an hour. 



C.K. Drinker, Carbon Monoxide Asphyxia, Oxford Univ. Press 1938 gives the following figures 

 for CO by volume percent : 



Gasoline automobile exhaust gas 7.0 



Diesel engine exhaust 0. 1-0.33 



mometers or psychrometers. Rough esti- 

 mates can be made by the amount of dis- 

 comfort and the dripping of sweat. The 

 danger point could be determined by means 

 of clinical thermometers. If several mem- 

 bers of the crew are found to have 

 temperatures over 103°F, the situation is 

 critical. In an emergency some relief could 

 be secured by sponging the body with 

 alcohol. 



and the size of the crew it is easy to calculate 

 the number of hours before the condition 

 will became dangerous. On a long sub- 

 mergence it is desirable to keep the CO2 

 below 2 percent and the O2 above 17 percent 

 until shortly before the end of the dive. 



2 DuBois, E. F. Physiology of respiration in 

 relationship to the problems of naval medicine. 

 Part III. Submarine ventilation. U. S. nav. 

 med. Bull., 1928, 26, 8. 



