An Assessment of Shear Damage to Southern Pine Sawlogs

Hydraulic tree felling shears are common on mechanized logging operations in the southern pine region. Shears cut lower stumps and are more productive than chainsaw felling but often cause damage to the butt log. Field inspections of l,557 shear-felled loblolly pine trees found three types of shear damage: stump-pull, splits, and shatter. While it is believed that stump pull and splits can be eliminated by proper shear and carrier maintenance and operator technique, some amount of shatter is inherent to the shearing process. Ninety-six logs, felled with properly maintained and operated scissor and directional shears, were sawn into 2 by 4’s, randomly end trimmed at 0, 2, 4, and 6 inches, and dried. Pieces were graded to determine any degrade directly resulting from shatter. A 6-inch trim was found to eliminate 94 percent of the shatter damage and is recommended for a log diameter distribution similar to that tested. In addition, the directional shear was found to cause less shatter to the larger logs and is recommended over the scissor shear for trees with stump diameter above 17 inches.

You must be logged in to download any documents. Please login (login accounts are free) or learn how to Become a Member