Fatigue Management

I asked him (an officer) to let us bivouac, which he did, so
we just fell down and slept, rain and all, and shells falling
all about us, but we were too exhausted to bother, we didn't
mind if we were killed, it was terrible.
CPL A. Thomas
A.I.F., France, October 1916
f. Odd behaviours. These may include talking ‘gibberish', neglect of
routine tasks, stupid accidents, hallucinations and inconsistent
work and behaviour.
Operational effectiveness increasingly relies on complex mental processes
that are highly susceptible to the impact of fatigue.
Some Effects of Fatigue on Performance
Reduced Attention. Soldiers are slow to notice occurrences in their
environment such as the approach of an enemy.
Communication Difficulties. Increasingly, it is
difficult to decide what needs to be said, how to say it
or what someone else said; for example, soldiers
cannot formulate coherent messages and may omit
important information in orders or reports. Speech
may become unintelligible.
Mood Changes. Significant changes in mood
normally accompany performance degradation.
These almost always include increased irritability and can entail depression
and apathy.
Inability to Concentrate. Maintaining attention to the task at hand, for
even a few seconds, is difficult. Soldiers cannot follow complex directions or
perform numerical calculations and are easily confused.
Increasing Omissions and Carelessness. Soldiers begin to skip tasks,
miss events and make mistakes, for example, failure to perform weapons
checks or remember the action state of weapons. A common and dangerous
sign of chronic fatigue is unauthorised discharges.
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Performance
Deterioration:
Rule of Thumb
The battle had raged all night and was still raging ...
Kennedy (Battalion CO) looked up at me from deeply
sunken eyes. His voice sounded inexpressibly weary,
lacking the bark and bite with which I was so familiar.
A 25 % decline in
mental performance
for each successive
24 hrs without sleep
Farley Mowat
And No Birds Sang, 1979