This paper studies the noise and vibrations transmitted to the crew of a pusher with eight barges sailing upstream the Danube River, between Cernavoda and Drobeta, with a staff consisting of a captain, one coxswain, one mechanic and three sailors. The research was conducted over a one-week period in August 2018. The navigation time was 24/24 h and the seafarers’ schedule was 4/8. Determinations were made on three different workers: Coxswain, mechanic and sailor. The meteorological parameters and the Danube river levels, the sound level and the transmitted vibrations, as well as the body temperature and blood pressure of the subjects were measured. The periods of activity and sleep were analyzed by means of an actigraph. Our research findings indicate that people worked overtime, slept less than necessary and, generally, did not observe the official program. The noise (LEP,d = 92 dB) and vibration levels (a total exposure A(8) = 4.1 m/s2) also contributed to the sleep disorder. Such effects were accompanied by increased body temperature and blood pressure. Synthesizing, it can be concluded that: The peak (acrophase) of the work capacity was from 9:00 to 11:00 and from 17:00 to 19:00, which represent the maximum efficiency periods. More specifically, the highest mental performances were recorded in the morning, while the maximum physical ones were to be seen in the afternoon. The minimum efficiency period was from 13:00 to 15:00. Decreases in the work capacity were identified at 23:00 (reasonably low level) and 3:00 (extremely low level).

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Abstract. This paper analyses the influence of whole-body vibrations on human performance; for this it was investigated how a group of men (20-29 years of age) and a group of woman (21-31 years of age) answered to specific requirements after being subjected to vertical vibrations under controlled laboratory conditions for 10-25 min. The vibrations were generated by a vibrant system with known amplitudes and frequencies. Accelerations were measured with NetdB -complex system for measuring and analysing human vibration and they were found in the range 0.4 -3.1m/s 2 . The subjects' performances were determined for each vibration level using specific tests. It can be concluded that exposure to vibrations higher than those recommended by ISO 2631 significantly disrupts how subjects responded to tests requirements.

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