1. BRM Ch07 Fatigue

2. Technical questions What is sleep apnea? How common is it?
List symptoms of fatigue.
What is circadian rhythm?
What is cumulative fatigue?
List factors that cause fatigue.

3. Captains do not get paid to sleep.
The complete responsibility that goes with being a ship’s master carries with it the complete demand of being on-call 24 hours a day, 7 days a week.
The standing orders of most captains carry specific instructions about being called no matter what time of day or night in case of navigational problems, unusual traffic conditions, adverse weather, or limited visbility.

4. Case study：
M/V World Prodigy grounded on a rocky ledge.
Spilled 3000,000 gallons of diesel oil.
The captain had been up and on watch for almost 36 hours.

5. Case study:
M/V Star Princess grounded on Poundstone Rock.
Total loss more than $27 million.
The pilot suffered from sleep apnea.
A person with sleep apnea has phtsical conditions that cause breathing to stop until he or she suddenly wakes up.

6. Consequences of fatique
Fatique is often overlooked as contributing to the catastrophe because other factors seem to outweigh it.
Inadequate planning, communications failures, and loss of situational awareness often appear to be more immediate causes for ship mishaps.

7. Sleep fundamentals When we are tired, we don’t think very clearly:
We overlook things, our judgement deteriorates, our percep- tions diminish, we become impatient with ourselves and others, and we find it difficult to concentrate or we tend to concentrate on one thing to the exclusion of all other things.

8. Circadian Rhythm
Human beings have a nature biological rhythm that makes us wakeful during daylight.
Our circadian rhythm is a 24- hour period that generally includes about 8 hours of sleep during the hour of darkness.
Human being are least alert in the very early morning, around 4 or 5 a.m..

9. Minimum Daily Sleep Requirement
Most humans need 8 hours of sleep in a 24-hour period.
Within our sleep periods, however, we have sleep cycles.
REM sleep (the sleep we have while we are dreaming).
NREM sleep (nondreaming sleep).
REM sleep and NREM sleep alternate in cycle that are about 90 minutes long.
Strategic napping

10. Cumulative Fatigue
Increasing sleep deficit, resulting in cumulative fatigue.
Cumulative fatigue can only be overcome by getting sufficient sleep until our bodies are fully rested.

11. Fatigue and Work
At the end of watch, whether it is eight in the morning or midnight, the watch-stander is tired, and, being tired, he or she will begin to experience some of the symptoms of fatigue no matter how much rest he or she got before watch.

12. Overall Result
Who
have suffered even minor sleep deprivation for any period of time,
suffer from accumulated sleep deprivation by losing sleep for several days in a row,
are working at unusual hours, and
are finishing their normal work period.

13. USCG statistical data show that as much as 18 percent of all significant shipboard mishaps occur between the hours of 0700 and
Peak accident time also occur each of the usual watch change hours: midnight, 0400, 1200, 1600, and 2000.
Particular vigilance should prevail during the change of watch when routine distraction and confusion can be augmented by fatigue.

14. Fatigue as a consistent factor
Fatigue is always a contributing factor.
Sleep with interruption, conclude that none of the crew were properly rested.
Case study：
Eisenhower collided with the Urduliz.
Exxon Valdez grounded.

15. Fixing fatigue
First thing to do is make sure that we have no undiagnosed sleep disorders.(sleep apnea)
The best way to combat fatigue is to get adequate rest each and every day.
US Code of Federal Regulations (CFRs), dictate a minimum of 10 hours rest in any 24-hour period, of which at least 6 hours must be continuous.

16. One of the first thing fatigue does is impair judgement;
Second, someone who is tired becomes less communicative and is less willing to talk about anything.
Third, an individual suffering from fatigue will work more slowly and is more likely to commit errors in work.

17. Rest times
STCW
Every 24 hours, at least 10 hours rest, continue working hour not more than 14 hours, at most two rest periods, one at least 6 hours.
ILO
In 7 days working time not more than 72 hours. In 24 hours at least 10 hours rest. Least rest hours, in 24 hours should be 10 hours, in 7 days should be 77 hours.
OPA 90
In 72 hours , no more than 36 working hours.

18. Discussion questions
We have all stood watches when we have been tired. Discuss the time you were most tired on watch.
Why didn’t World Prodigy’s chief mate suggest that he stay on the bridge instead of going below to recalculate the ship’s draft?
Discuss cases in this book, but not in this chapter, that have elements of fatigue in them.
What did you think of the nontraditional watch schedule presented in this chapter? Would it work? Have you ever tried it?
What things are done on your vessel to minimize fatigue? What things are done that do not minimize fatigue?