Productivity of manual loading system of logs in El Salto, Durango, México

Introduction: In some forest regions of Mexico, it is common for short-sized logs to be handloaded; however, the efficiency of this operation has been poorly documented.Objective: To evaluate the effect of log size and distances on manual loading productivity in forests in the region of El Salto, Durango, Mexico.Materials and methos: A total of 738 manual loading cycles of 4 ft (1.22 m) logs were timed using the ‘back-to-zero’ method. Log volume and loading distances were taken by direct in-situ measurement. Average log diameters were divided into three categories and loading distances into four. The system yield was determined by relating log volume to total loading time.Results and discussion: Manual loading yield was established from 3.80 to 16.42 m3∙h-1, influenced by log diameter and loading distances, because 82 % of the loaded volume corresponds to logs with diameters from 10 to 30 cm, which are loaded every 12 s; logs larger than 30 cm require 27 s. Also, 91 % of the loading volume is carried out in the first 10 m of distance from the truck and takes 15 s per log, and, at longer distances, 35 s.Conclusions: It is possible to increase the performance of the operation by considering maximum loading distances in the order of 10 m