Skip to main content
Forces and Stresses Generated During Rigging Operations
Arboriculture & Urban Forestry (2009)
  • Brian C.P. Kane, University of Massachusetts - Amherst
  • Sergio Brena, University of Massachusetts - Amherst
  • Wesley Autio, University of Massachusetts - Amherst

Rigging is one of the most dangerous aspects of arboriculture, yet there are no robust studies of the forces and stresses generated during rigging. Compounding the inherent danger of rigging is the structurally-deficient condition of many trees that are removed using rigging. Red pines (Pinus resinosa Ait.) (n = 13) were removed using conventional techniques, and forces at the block and in the rope were measured as the top, and four subsequent pieces were rigged with a block and Port-A-Wrap. Stress in the trunk at breast height was calculated from strain measurements and each tree’s modulus of elasticity. Multiple regression was used to determine which independent variables (mass of piece, fall distance and fall ratio, notch angle and depth) best predicted forces. Tops and pieces exhibited different relationships with mass, which was the best predictor of force at the block and tension in the rope. Other variables were not as important and exhibited counter-intuitive relationships with forces. There were few differences in stress generated when removing tops and pieces, which appeared to be due to greater deflection higher in the trunk when tops were removed.

  • Rigging,
  • Turnk Stress,
  • Biomechanics
Publication Date
Citation Information
Brian C.P. Kane, Sergio Brena and Wesley Autio. "Forces and Stresses Generated During Rigging Operations" Arboriculture & Urban Forestry Vol. 35 Iss. 2 (2009)
Available at: