Fatigue condition under the engine room environment and improving work accuracy

Familiarization of the work could reduce the difficulty of a given task, and workers can perform the work quicker. However, familiarization of the work in a long term may cause the work to be boring as it generally reduces the stress. As a result, the worker might develop an unsafe behavior through reduction of alertness. Instead of repeatedly performing the tedious work, as a common method for maintaining the accuracy at work, there can be an alternative method by inserting a break into the working schedule. The types of work in the engine room are quite diverse since there are different types of engines and machineries operating together or independently. Nevertheless, the break taken by each engineer working in engine room might be different according to operating situation. This study uses an experimental case to investigate the fatigue and its relationship to work accuracy. This experiment utilizes an equipment consist of short pipes and flange connections used in engine room. A student carries out tightening experiments to keep the flanges in place by bolts and nuts. The biological reactions were measured in an activity by heartbeat sensor and electroencephalogram head-set. The tightened bolts were made loose by torque wrench, while torque was measured simultaneously. The relations between the biological reactions and the working accuracy are investigated according to elapsed time and presented in this paper. It was concluded that working environment in the ship engine room could be improved using the optimum rest time concept, discussed for the working accuracy and safety level.