RT Journal Article
SR Electronic
T1 Branch Break Assessment: An Unexpected Accident with a Professional Arborist
JF Arboriculture & Urban Forestry
FD International Society of Arboriculture
SP 278
OP 285
DO 10.48044/jauf.2024.009
VO 50
IS 4
A1 Scipioni, Marcelo Callegari
A1 Delben, Guilherme Jurkevicz
A1 Modes, Karina Soares
YR 2024
UL http://auf.isa-arbor.com/content/50/4/278.abstract
AB Background Arborists are important in both the maintenance of urban trees and research on forest canopies. Tree climbing is hazardous work. This study investigated the causes of a branch-breaking accident involving a certified arborist.Methods The branch was 11 cm in diameter. The density and mechanics of the branch wood were studied; the measurable stresses and deformations until the material ruptured were analyzed. The position of the tree climber and the applied forces were calculated, including the shear stresses, the bending moment, and the support reaction suffered at the point of rupture.Results The shear stress grew exponentially from V = 25.78 MPa; a shifting of the angle of the lanyard by > 45° and moving one meter toward the tip of the branch caused a 64.67% increase in shear stress. The support distance of the arborist’s body on the one anchor point on the branch, combined with the angle of force on the same branch, caused the imminent rupture of the branch’s base. The study provides evidence that the arborists should avoid traveling over small horizontal branches using only one safety point with lanyards.