Effect of gaff design on linemen's perception of the climbability of red pine utility poles of pre-selected wood hardness

The aim of this study was to investigate the effectiveness of a gaff adapted for chromated copper arsenate (CCA) in order to improve the linemen's psychophysical perception of pole climbability compared to the standard gaff used by Hydro-Quebec's staff. Three red pine poles were selected in arange ofwood hardness where the linemen's acceptability level is around 30 to 50 percent (hard poles) and three others in a range showing generally over 80 percent of acceptance (soft poles). In a first series of tests, psychophysical data collected from 16 line workers showed that the CCA-adapted gaff provided a significant but limited improvement (10% to 15%) in the perception for the hard poles. Conversely, the use of the CCA-adapted design in conjunction with the soft poles led to a slight but significant deterioration in the linemen's appreciation. These soft pre-selected poles, which met total acceptance with the standard gaff, were found to be unacceptable by about one-third of the linemen when the CCA-adapted gaffwas used. In a second series of tests, the same workers were sequentially equipped with an instrumented climber from each gaff design to record gaff penetration and gaff impact values. The results confirmed the possibility of using a combination of these physical parameters for estimating the linemen's perception when assessing the hard poles. However, the situation reported by the linemen for the soft poles cannot be followed with the same level of discrimination. In a third series of tests, a mechanical device that directly provides a climbability index was used to assess the poles. As expected, the measured values showed trends very close to those observed with the instrumented climbers. From these results, it is obvious that a third parameter such as gaff withdrawal force should be measured to use the setup for discriminating the gaff effect over these pre-selected soft poles.