In recent years, the German Social Accident Insurance Institution for the energy, textile, electrical and media products sectors (BG ETEM) has been faced with managing several suspected cases of formally recognized occupational disease No BK 2301 among fitters of overhead contact lines. Little information is available on the noise exposure associated with this job profile. Noise analyses from the companies are not available, nor have meaningful measurements been conducted by the accident insurance institution itself. Reference is frequently made to an IFA study conducted in 1995 in which two full-shift measurements returned noise levels of 84 and 86 dB(A). However, this study covers only a part of the tasks and areas of work of overhead contact line fitters. During tasks involving excavators and piledrivers and on construction sites in tunnels and adjacent to sections of track in use, in particular, noise exposure can be expected to reach levels capable of causing hearing loss.
The present study was to produce validated results concerning the noise exposure situation associated with this job profile. The results may also be useful for prevention purposes (risk assessment, need for hearing protectors).
Dosemeters were used in order to determine the noise exposure of fitters of overhead contact lines during their various tasks, in their various areas of activity and under different underlying conditions. For a range of procedures, such as fitting of lines on the masts, the measurement method had to be suitably adapted and the results validated by comparative measurements. Observation of the test subjects was to yield further findings concerning the tasks and the associated time components.
Owing to the number of areas in which overhead contact line fitters work and of the sub-tasks that they perform, it was not possible for the noise exposure level to be determined for all conceivable job profiles.
Since the findings were consistent with the comprehensive results obtained by the AUVA (the Austrian Workers' Compensation Board), further measurements within this project were not required. Together with the measured data obtained in Austria, sufficient values from the field have now been obtained to permit assessment of the noise exposure situation in a number of tasks performed by fitters of overhead contact lines.
For example, equivalent continuous noise levels of between 90 dB(A) and 110 dB(A) occur during piledriving in and adjacent to the trackbed, whereas equivalent continuous noise levels in the region of 80 dB(A) occur during the actual fitting work. Altogether, it can be concluded from the measurement results that fitters of overhead contact lines are exposed to an equivalent continuous noise level exceeding 85 dB(A) only during a small number of tasks, such as piledriving and demolition work or during the use of tools such as hammers and angle grinders. Depending upon the duration and frequency of such tasks, the associated noise exposure must be determined on a case-by-case basis.
The measurement results obtained serve as a valuable basis for preventive activity, particularly for decisions concerning occupational medical examinations and the selection of suitable hearing protectors.
electrical engineeringType of hazard:
prevention, risk assessment, noiseDescription, key words:
typical occupational exposure, noise exposure level, installation of overhead contact lines