Development of a puller-buncher for harvesting southern pines with taproot attached

Abstract

A harvester-buncher that mounts on the front of a wheeled skidder has been developed to pull entire pine trees from the ground like carrots. Two elements are central to its design. The first is a scissors-type grip equipped with a pair of stout horizontal knife blades that close at the groundline and bite several inches into the stem from opposite sides of the tree. The second element in the design is a clamshellhinged tubular shear 22 inches in diameter and sharpened on tJte lower edge. With the scissors grip as an anchor, the shear is forced vertically into the ground to a depth of about 11 inches, levering lateral roots all around the tree. At this depth, broad steps on opposite sides of the tubular shear strike the ground and prevent further penetration; application of additional force on the shear causes the steps to bear against the ground and the grip to rise about 9 inches, thereby jacking the tree free of the ground with taproot attached. Finally, the complete tree is lifted into the air and bunched for skidding.

Citation

Koch, P.; Coughran, S.J. 1975. Development of a puller-buncher for harvesting southern pines with taproot attached. Forest Products Journal 25(4):23-30