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Strength demands of line handlers on the Panama Canal.

Gallagher-S; Unger-R
American Industrial Hygiene Conference and Exposition, June 1-6, 2002, San Diego, California. Fairfax, VA: American Industrial Hygiene Association, 2002 Jun; :59
Vessels transiting the Panama Canal are guided through the locks using locomotives that are connected to the vessels by menas of wire ropes or cables. Crews of line handlers must attach these cables to bitts on the vessel. This task entails high strength demands and results in a high incidence of low back pain. As a result, the Panama Canal Commission requested that the National Institute for Occupational Safety and Health (NIOSH) evaluate the strength requirements of the job and strength capabilities of line handlers. Task demands were evaluated using a digital force gauge during transit of a Panamax vessel through the Miraflores and Pedro Miguel locks. Capping the bow bitts consistently resulted in the highest force demands, averaging 1144 N of force. Capping the stem bitts required less force (1034 N), while capping the midships bitts were least stressful (averaging approximately 311 N). Individual and team pulling strengths of a crew of line handlers were evaluated using three angles of pull. Individual strengths were greatest when pulling upwards (average of 512 N+- 222.5), followed by pulling downwards (average of 467 N :t 133.5), and was least when pulling horizontally (average of 401 N+- 178). In team strength tests, arranging the crew in order of stature was important. When pulling upwards, arranging the crew from shortest (in front) to tallest increased strength by 12.5% compared to the opposite arrangement. When pulling downwards, having the tallest in front increased strength generated by the team by 25% compared to the opposite order. Order of the team by stature had no effect on horizontal pulls. Data suggest that capping bow and stem bitts on Panamax vessels requires at least four and perhaps as many as five line handlers in order to meet strength demands of the task.
Workers; Transportation; Transportation-workers; Back-injuries; Workplace-monitoring; Musculoskeletal-system-disorders
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Research Tools and Approaches: Control Technology and Personal Protective Equipment
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American Industrial Hygiene Conference and Exposition, June 1-6, 2002, San Diego, California