Skip to main content

Two-Dimensional Analysis of Logging Tail Spars

Buy Article:

$21.50 plus tax (Refund Policy)

A beam-column analysis of a skyline-logging tail spar was formulated and an example analysis made of a second-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) spar (15.-in. dbh) rigged at 40 ft. The analysis takes into account the taper of the spar tree, the flexibility of the base of the spar, and the eccentric restraining load at the top provided by guylines. Allowable skyline tension on the tail spar is shown to vary with skyline angle and guyline pretension. An optimum guyline pretension that produces the greatest capacity in the spar tree was found to be within a range attainable by hand tightening. The variation of allowable skyline tension with rigging height and spar diameter also is shown. For. Sci. 33(4):971-983.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Data/Media
No Metrics

Keywords: Capacity envelope; beam column; loading envelope

Document Type: Journal Article

Affiliations: Logging Systems Specialists, Umatilla National Forest, Pendleton, OR 97801

Publication date: 1987-12-01

More about this publication?
  • Forest Science is a peer-reviewed journal publishing fundamental and applied research that explores all aspects of natural and social sciences as they apply to the function and management of the forested ecosystems of the world. Topics include silviculture, forest management, biometrics, economics, entomology & pathology, fire & fuels management, forest ecology, genetics & tree improvement, geospatial technologies, harvesting & utilization, landscape ecology, operations research, forest policy, physiology, recreation, social sciences, soils & hydrology, and wildlife management.
    Forest Science is published bimonthly in February, April, June, August, October, and December.

    2016 Impact Factor: 1.782 (Rank 17/64 in forestry)

    Average time from submission to first decision: 62.5 days*
    June 1, 2016 to Feb. 28, 2017

    Also published by SAF:
    Journal of Forestry
    Other SAF Publications
  • Submit a Paper
  • Membership Information
  • Author Guidelines
  • Podcasts
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more