Comparative ergonomic analysis conducted during the TAQP project of various techniques during the loading and unloading of aircraft

Status:

completed 04/2011

Aims:

During the TAQP project (the German abbreviation stands for technological innovation, work organization, training and prevention), two new technical systems were introduced in the baggage loading area at Frankfurt airport. The systems, a vacuum lifter and a rollertrack conveyor (Powerstow) are promised to reduce the work load of the baggage handlers and increases in efficiency. The intervention study was intended to quantify the decreasing of the work load and to demonstrate the influence of the technical aids upon the working process and the potential of organizational measures and training for improvement of the results. The results serve as guidance for further investment by Fraport AG, and as a starting-point for sustainable effects for other airports and for other providers of ground services.

Activities/Methods:

Following a training period, the stress-reduction effect of the technical systems was determined by means of the CUELA measurement system worn by the worker. For this purpose, the work load upon the baggage handlers and ramp agents were measured before and after the technical intervention. The measurements were performed on Fraport AG staff at regular workplaces, and the effect of stress reduction studied. The impacts upon the effectiveness and efficiency of the working procedures were also recorded. Ten male baggage handlers in the baggage transfer centre and 13 male ramp agents in the loading service volunteered to act as test subjects in the study. Each test subject performed his tasks both conventionally and at the technically modified workplace. The average measurement duration per test subject and work situation was approximately 45 minutes in the central baggage room and approximately 20 minutes in the aircraft holds. The measurement data for body postures and movements were assessed by means of the OWAS method and the IFA-posture code of the Institute for Occupational Safety and Health of the German Social Accident Insurance. Further the body postures were evaluated for joints in accordance with the neutral-zero method. Manual load manipulation operations were interpreted comparatively in terms of the load weight, the duration, and in combination with the associated body postures.

Results:

Use of the vacuum lifter reduces by 83% the cumulative effective mass of the baggage items which each test subject in the baggage transfer centre lifts manually within an hour. The number of baggage items lifted was reduced by 71%: of an average of 230 baggage items handled per hour, 64 were still handled manually. For some baggage handlers, relief as high as 90% was measured, i.e. only 10% of the baggage items were still handled manually. The body posture was not significantly improved by the use of the lifter; inclinations of the torso accounting for 80% of the total measurement duration are however within the neutral range in any case, and may therefore be considered not critical. The measurements showed that use of the lifter results in a minor average reduction in working speed of 21%; in terms of the daily capacity however, this results in a handling rate that is still greater than the average baggage volume. The use of the rollertrack conveyor, which transports the baggage into the airliner at the point of loading, slightly reduces the stress upon the workers in loading service. Stresses caused by loading activities in the aircrafts hold are a result of the low compartment height on narrow-bodied airliners. This situation cannot be alleviated by the rollertrack conveyor; the proportion of body postures placing stress upon the knee is therefore largely unaffected by its use. The forward inclination of the trunk can be improved by means of the Powerstow during loading the aircraft; during unloading however, the rollertrack conveyor does not bring about any improvement in the body posture. A clear improvement in the stress situation is seen during manipulation of the baggage items. Analysis of the duration of manipulation shows that in conjunction with the adjustable loading table, the rollertrack conveyor clearly alleviates the force required to be exerted by the loading workers. The duration of load manipulation is ultimately reduced by 53% during loading of the baggage items and by 45% during unloading. The use of the rollertrack conveyor was less effective in terms of its impact upon the handling times. Use of the rollertrack conveyor increased the unloading time per item of baggage by an average of approximately 40%; during loading, the increase was a modest 12.5%. Net unloading times of five to six seconds per item of baggage were nevertheless recorded for unloading both conventionally and with the rollertrack conveyor. Delays were a result of insertion of the system into the body of the aircraft.

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