An Evaluation of Tool Design and Method of Use of Railroad Leverage Tools on Back Stress and Tool Performance

In: Human factors: the journal of the Human Factors Society, Volume 28, Issue 3, p. 303-315

Abstract

The effects of railroad claw bar design factors and method of use upon performance and back stress were investigated. Novice and experienced subjects were tested for their ability to use the claw bar to remove track spikes. Two standard claw bar designs were evaluated. The method of tool use was described by body position relative to the claw bar and by body action. Tool design had no significant effect on either tool-lifting performance or back-stress measures. Body action patterns, but not body position, were found to have significant effects on both performance and back stress. Results support the use of a body action involving the use of the arms only. This method provides the required impulse forces with minimum back stress and also provides proper balance to avoid falls from sudden spike removal. Proper technique, as opposed to total force application, was found to be the key factor in tool use. Novices attempt to apply a large, sustained force using the whole body, whereas experienced trackmen use a snapping action to generate the required forces. Trackmen generated 50% more lifting force than did the novices.