A comparison of grapple yarding and choker yarding in British Columbia

Abstract

This report examines the two major systems used for harvesting on the coast of British Columbia. The traditional choker yarding system has been replaced in many instances by the grapple yarding system over the last 15 years. The grapple yarding system is very cost efficient when the number of scheduled hours per year is high. The large capital investment required for the grapple yarding system dictates that the utilization level must be relatively constant and high. In "unfavourable" ground conditions the choker yarding system is still the most efficient with the cost approximately $6.56 to $7.15 per cubic metre of wood harvested. "Favourable" ground conditions lead to a grapple yarding cost of $3.69 to $3.90 per cubic meter, compared to the choker yarding cost of $5.02 to $5.47 per m3 on similar terrain. Keywords: Cable yarding systems Choker yarding Grapple yarding