An economic study of the technology of harvesting and transport systems used in clearfelling Acacia mearnsii, Eucalyptus grandis and Pinus patula.

Abstract

Objectives of this thesis are to project the description and supply of Black labour in the forestry industry of southern Africa, survey harvesting and transport systems used overseas and locally, select and adapt a method to analyse and quantify local systems and present the results of this research. The next objective is to write a computer programme which uses these results to estimate labour and machine requirements with their respective production rates and give standard cost analyses. This supplies the detail for system selection, daily management of harvesting and transport operations and the basis for control by comparing projected production rates and costs with historical data. Although labour intensive systems are still being comployed, it was found that costs and unavailability of Black labour has forced a conversion to capital intensive systems. This trend is expected to continue at an increasing rate. Many European machines appear to have developed from forwarders with various heads fitted to their cranes to perform different operations. American equipment has tended to develop around the articulated front-end loader. In South Africa, the locally invented three-wheel loader has been adapted to fill a similar role. However, it is premature to forecast the direction southern African forestry will follow. Of the possible work measurement techniques, the so-called stop watch methods were selected as they proved to be the most accurate, penetrating and rapid. Results were reproducible and highly significant when regressed on the appropriate tree, terrain or work site dimensions. A survey of available computer simulation programmes revealed that in their present form they were unsuited to southern African harvesting and transport operations investigated. Consequently, the writer wrote a programme in FORTRAN 77 which contains all results in this thesis and analyses timber harvesting and transport. The programme, named Techno-Economic Analysis of Logging (TEAL), supplies its results in a form suitable for both field staff and senior management. TEAL analyses have been found to compare closely with efficient operations. Many of this thesis' data have been compiled into tables giving piece work rates in simplified form. These are presented in appendices.