Productivity Measurements of Two Waratah 234 Hydraulic Tree Harvesters in Radiata Pine in New Zealand

Abstract

Abstract Two Waratah 234 single-grip harvester heads were assessed for productivity and log-processing accuracy while working in radiata pine clearfell operations in New Zealand forests. Estimated productivity, processing stockpiled trees into logs on a landing in a ground-based operation, was 77 m3 per productive machine hour (PMH) in an average tree size of 1.63 m3. In a yarder-based trial, processing trees into logs on a landing, productivity was 77 m3/PMH in an average tree size of 3.1 m3. Length-measuring accuracy in a later trial was shown to be within ± 5 cm for 93% of logs. In a second ground-based trial, estimated productivity for an average extracted tree size of 1.95m3 was: • 51 trees/PMH (100m3) for felling, tree-length delimbing and bunching. • 73 trees/PMH (143m3) for tree-length delimbing (butt-first) and bunching of manually felled trees.