Public pressure to end clearcut logging, and changing forest management needs have
increased opportunities for partial cutting in British Columbia's second-growth coastal forests.
Production economics and engineering design of cable harvesting systems for partial cutting in
second-growth forests of British Columbia (BC) are largely unknown. Scientific research and
working experience in partial cutting forest harvesting operations in coastal areas of the Pacific
Northwest of North America is from the United States or from selection harvesting of old growth
forests in coastal BC prior to 1935.
Time and motion studies were conducted in fall of the 1992 and spring of 1993 on two
cable yarders in second growth coastal forests (on Vancouver Island) of BC. The goals of the
studies were to design a forest engineering system for field layout of cable harvesting systems in
partial cutting, develop production and cost models for the two yarders , compare the
productivity and costs of partial cutting and clearcutting, and develop models for optimal spacing
of skyline yarding corridors.
Results showed that forest engineering of partial cutting with cable yarders was dependent
upon corridor spacing and tailspar tree location, size and species. Production and cost analyses
showed that wider corridors and larger crew sizes were more efficient, but also that productivity
gains from larger crew sizes did not result in lower operating costs. Clearcutting in all instances
was shown to be more efficient and cost effective than partial cutting. The coastal stumpage
appraisal system was shown to vastly under-estimate the added costs of partial cutting in relation
to clearcutting. Optimal skyline corridor analysis and comparisons demonstrated that lower variable yarding costs resulted from wider corridor spacing, both contractors spaced yarding
corridors narrower than optimal, and costs could be reduced by optimal spacing of corridors. The
quantity of timber harvested with partial cutting is increasing annually, and knowledge and
experience in these harvesting systems is necessary and will be an asset.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:BVAU.2429/4425 |
| Date | 05 1900 |
| Creators | Rutherford, Dag |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Relation | UBC Retrospective Theses Digitization Project [http://www.library.ubc.ca/archives/retro_theses/] |
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