Introduction:

In some forest regions of Mexico, it is common for short-sized logs to be hand-loaded; 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.

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