Fatigue

• 17.04.2015
• 15:53

Fatigue can be a difficult concept to understand. Often it is explained as a state of exhaustion that results in diminished physical and/or mental capacity.

Impact on work performance

This condition can be explained as a result of physical, mental or emotional exertion and may have impact on the individual’s capacity in terms of strength, response time, coordination, balance, decision making, etc.

Sleepiness vs fatigue

Many interpret the word fatigue as a synonym to sleepiness.
Lack of sleep and imbalanced sleep cycle are serious risk factors in shipping. There are a number of examples of disastrous maritime accidents resulting from the master falling asleep on duty.
However, one can be tired and exhausted without being sleepy. This will make us less alert as well as influence our ability to handle unexpected situations.

The individual

In addition to being a safety problem and increasing the risk for accidents, it is important to keep in mind that fatigue may also have a direct negative health impact on the individual, both physically and mentally.

Working environment

Fatigue could also have impact on the working environment on board. Reduced awareness and work capacity, irritability, etc. could result in increased strain level for colleagues.

Causes of fatigue

Several international studies show that there are many factors that may lead to fatigue:

• Lack of sleep or poor sleep quality. This may be due to sleeping problems, interrupted sleep, trouble relaxing properly, poor weather conditions and rough seas.
• Negative environmental factors. Examples may be bad indoor climate, poor comfort, noise and vibrations.
• High work pressure and high levels of stress. This may be due to extra shifts, time pressure, manning level or bad organization.
• Frequent port calls. This may interrupt working patterns, as well as resting and off-duty time.
• Unfavourable weather conditions.
• Constantly working more than 12 hours a day. There is a clear connection between the number of working hours and fatigue.
• Boredom. Passivity and little activity also promote fatigue.

What can I do?

Immediately:

• Inform your supervisor.
• Take a break and get some fresh air, go for a quick walk on deck if possible.
• Take 30 minutes off and schedule a 20 minute nap.
• Drink water and eat a light meal.
• Check the indoor environment, air out and make sure that the temperature is as comfortable as possible.

In the longer term:

• Discuss the duty roster with your supervisor.
• Try to make sure that you are well rested before you start your shift.
• Discuss with your supervisor and with your colleagues, and try to find out why crew members suffer from fatigue.
• Evaluate relevant environmental factors or more organizational circumstances such as duty schemes, use of overtime, resting time, manning level on board, etc.
• Agree on measures to prevent fatigue and how to solve the situation if fatigue arises.

General understanding

Fatigue is the result of several factors reinforcing each other, for instance little sleep combined with long shifts, monotonous work and perhaps bad indoor climate.  
Regulations, duty schemes and manning all limit the amount of sleep workers get at sea. Type of duty scheme is determined by the shipowner in accordance with international and national regulations.  It is important that shipowners consider risk of fatigue when the crew, duty roster and duty scheme are settled. By focusing on the mentioned risk factors for fatigue, one can try to organize so that workers get enough rest and sleep.

See our Fatigue brochure (pdf)

Publications regarding fatigue:

IMO guidance on fatigue (pdf)
Seahealth.dk
Fatigue at Sea
Results and recommendations for managing fatigue in watch systems onboard
Forskningsprosjektet Horizon 2011
Cardiff research programme

IMO guidance on fatigue (pdf)
Seahealth.dk