RECOMMENDATIONS FOR FURTHER RESEARCH 



339 



under both current and modified watch 

 schedules. The tests should be performed 

 at different hours of the day and night and 

 at various intervals of time following 

 awakening. The new routine has to sell 

 itself by virtue of greater efficiency resulting 

 from its adoption, as well as its cheerful 

 acceptance by the submarine personnel. 



B. Watch Schedules Based on a 12-Hour Cycle 



The current arrangement of "4 hours on 

 and 8 hours off" lends itself to an investi- 

 gation into the possible advantages of a 

 frank 12-hour cycle of wakefulness and sleep. 

 The entire personnel would be divided into 

 three sections, operating under the following 

 time table: 



Section I 



Watches: 0-4, 12-16. Meals: 4^5, 1(H-11, 

 16^-17, 22^-23. Sleep: 6-10, 18-22. 



Section II 



Watches : 4-8, 16-20. Meals : 2^-3, 8^9, 14|-15, 

 20^-21. Sleep: 10-14, 22-2. 



Section III 



Watches : 8-12, 20-24. Meals : ^1, 6^, 12|-13, 

 18^19. Sleep: 2-6, 14-18. 



General features common to all schedules : 



1. One 4-hour watch during each waking period 

 of 8 hours; two 4-hour watches per 24 hours: 

 watches of equal duration and spacing under 

 all schedules. 



2. Long stretches of free time : eight hours out 

 of each 12, or two 8-hour periods per 24 hours. 



3. Four meals per 24 hours, or one every 6 hours, 

 with at least one hour between end of each 

 meal and beginning of watch period. 



4. Hours of sleep may be optional, falling 

 equally in each of the two 8-hour stretches 

 of free time between watches or falling pre- 

 dominately within one of the two 8-hour 

 periods. Hours of sleep may also be fixed 

 at 4 hours in the middle of each 8-hour period 

 of wakefulness, permitting the exclusion of 

 of non-sleepers from sleeping quarters and 

 the use of rotary bedding equipment. 



5. At least two hours elapse between awakening 

 and beginning of the watch. 



In these schedules the timing of the 

 watches would be fixed for the duration of 

 the cruise, but otherwise there are no changes 

 in the now prevailing hours of duty. How- 

 ever, sleep in four or five hour stretches 

 would fall in the middle of the "8 hours off" 

 period, and the cuHnary adjustment would 

 have to be even more radical than under the 

 first experimental routine suggested: two 

 meals, before and after duty, per 12 hours, 

 for each section, would mean a total of 12 

 meals prepared and served during every 24 

 hours. Again, the criterion of superiority 

 of the 12-hour cycle over the present skewed 

 24-hour one would have to be similar sleep- 

 wakefuhiess and body temperature curves 

 for all successive 12-hour periods. In addi- 

 tion, greater eflSciency would have to be 

 demonstrated by greater speed and accuracy 

 of carrying out typical submarine activities 

 under operational conditions. 



C. An Artificial Cycle of Activity 



The possibiHties of a cycle longer or 

 shorter than 24 hours should be investigated 

 under laboratory conditions. Since sub- 

 marine operations are likely to be carried 

 out under surface in the future even more 

 than in the past, there is no physiological 

 reason for adhering to the 24-hour alterna- 

 tion of day and night in scheduHng the time 

 table of duty, meals, recreation, and sleep. 

 Artificial cycles can be estabhshed, and the 

 greater temperature swings that are likely 

 to result from cycles longer than 24 hours 

 might lead to greater eflSciency during the 

 increased period of wakefulness. The men 

 would still be on duty only one-third of the 

 time, but on a 30-hour cycle would put in 

 altogether 10 hours of duty during 20 hours 

 of wakefuhiess, with 10 hours given over to 

 sleep. While being tried out under labora- 

 tory, rather than submarine-operational, 

 conditions, the same tests could be apphed 

 to the advantages of this scheme as have 

 been suggested for those discussed under 

 A and B. 



