202
L. Picu et al.
From Fig. 9, the dependence of the number of nails correct placed inside the holes
decreases over time, with the fatigue onset.
The best results obtained by Subject 6, with 76% correctly placed pins, followed
by Subject 5 with 70.33%. Subjects 3 and 4 had close outcomes: 57.3% and 60.3%,
respectively. Subject 2 had only 37%, and Subject 1 refused to participate in the
experiment on the last day. All tests were carried out at the workplace of each subject.
It results that the performance of the subjects decreases, as the days pass and
fatigue accumulates; so if on the first day more than 20 correct placed nails were
obtained, on the last day, their number was less than 15. Also, worse results were
obtained by the subjects who are overweight or obese (who get tired faster) as well
as by those who have a lower seniority in work, so they are less accustomed to stress.
Also, the age of the subjects has a great influence on efficiency; the crew is aging,
and half of the subjects said they have health problems. Smoking is a very important
factor when it comes to dexterity, consequently on the ability to solve a test that
highlights the subject’s handiness. If all these add to the totally unfavorable weather
conditions, there is an accumulation of risk factors that lead to modest results in
terms of subjects’ efficiency.
4 Conclusions
From the measurements made for WBV, it was surprising that T EAV and T ELV for
control room were higher than T EAV , or T ELV , for the engine room. Similar results
were obtained with HAV measurements.
This may be explained by the fact that the ship is quite old and that the vibrations
are more pronounced at the higher structures.
Also, the situation is serious in the case of daily noise exposure (L EP, d ) whose
average is 99.5 dB inside the control room and 107.6 dB for the engine room, so it
is exceeded by 17/26.6% compared to the Directive 2003/10/EC requirements.
As far as the effectiveness of crew members is concerned, it is reflected in the old
age of the subjects and the fact that among them are smokers and drinkers. Some
of these subjects have also several cardiovascular problems. It is also found that the
effectiveness of crew members decreases toward the end of the voyage because, in
addition to the fatigue accumulated during the journey, the other stressors: noise and
vibrations interfere. It is clear that engine room workers have lower performances
than those who worked in the control room.
All problems of the subjects (age and personal problems) are contributing to
the poor health caused by vibrations and noises; if to this are added irregular work
schedule, living on a boat for 2–3 weeks, extreme weather work, etc., it can be said
that it is necessary to create better working conditions for the crew: newer ships,
shorter work shifts by increasing staff numbers, etc.
Obviously, this study on an only six people crew and a single ship cannot be so
conclusive, but it is a starting point for future research.
L. Picu et al.
From Fig. 9, the dependence of the number of nails correct placed inside the holes
decreases over time, with the fatigue onset.
The best results obtained by Subject 6, with 76% correctly placed pins, followed
by Subject 5 with 70.33%. Subjects 3 and 4 had close outcomes: 57.3% and 60.3%,
respectively. Subject 2 had only 37%, and Subject 1 refused to participate in the
experiment on the last day. All tests were carried out at the workplace of each subject.
It results that the performance of the subjects decreases, as the days pass and
fatigue accumulates; so if on the first day more than 20 correct placed nails were
obtained, on the last day, their number was less than 15. Also, worse results were
obtained by the subjects who are overweight or obese (who get tired faster) as well
as by those who have a lower seniority in work, so they are less accustomed to stress.
Also, the age of the subjects has a great influence on efficiency; the crew is aging,
and half of the subjects said they have health problems. Smoking is a very important
factor when it comes to dexterity, consequently on the ability to solve a test that
highlights the subject’s handiness. If all these add to the totally unfavorable weather
conditions, there is an accumulation of risk factors that lead to modest results in
terms of subjects’ efficiency.
4 Conclusions
From the measurements made for WBV, it was surprising that T EAV and T ELV for
control room were higher than T EAV , or T ELV , for the engine room. Similar results
were obtained with HAV measurements.
This may be explained by the fact that the ship is quite old and that the vibrations
are more pronounced at the higher structures.
Also, the situation is serious in the case of daily noise exposure (L EP, d ) whose
average is 99.5 dB inside the control room and 107.6 dB for the engine room, so it
is exceeded by 17/26.6% compared to the Directive 2003/10/EC requirements.
As far as the effectiveness of crew members is concerned, it is reflected in the old
age of the subjects and the fact that among them are smokers and drinkers. Some
of these subjects have also several cardiovascular problems. It is also found that the
effectiveness of crew members decreases toward the end of the voyage because, in
addition to the fatigue accumulated during the journey, the other stressors: noise and
vibrations interfere. It is clear that engine room workers have lower performances
than those who worked in the control room.
All problems of the subjects (age and personal problems) are contributing to
the poor health caused by vibrations and noises; if to this are added irregular work
schedule, living on a boat for 2–3 weeks, extreme weather work, etc., it can be said
that it is necessary to create better working conditions for the crew: newer ships,
shorter work shifts by increasing staff numbers, etc.
Obviously, this study on an only six people crew and a single ship cannot be so
conclusive, but it is a starting point for future research.