It is a well-known fact that humans are subject to circadian alterations caused by the action of sunlight. This strongly affects their behaviour and skill, making them change their level of alertness from high at daytime to low at night-time. Taking into account this biological feature, and considering that commercial shipping is one of the oldest round-the-clock activities, raises the question whether bridge watchkeepers can carry out their tasks on night shifts with the same level of alertness as on day shifts. Furthermore, night bridge watchkeeping has to be performed in darkness or very dim light to improve the visual capacity of lookouts. A sample of vessel collisions was analysed and it was find out that this kind of accident tends to be more frequent and more serious during the darkness period of the solar day.

中文翻译：

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昼夜节律对航运事故的影响

众所周知，人类会因阳光的作用而发生昼夜节律变化。这极大地影响了他们的行为和技能，使他们的警觉程度从白天的高水平变为夜间的低水平。考虑到这一生物学特征，并考虑到商业航运是最古老的全天候活动之一，提出了一个问题，即桥梁值班员是否可以在夜班时以与白班相同的警觉水平执行任务。此外，夜间桥梁值班必须在黑暗或非常昏暗的光线下进行，以提高瞭望台的视觉能力。对船舶碰撞样本进行了分析，发现此类事故在太阳日的黑暗时期往往更频繁、更严重。