Stroke delimbers are very efficient at limbing trees and bucking them into logs. Often used in conjunction with feller-bunchers, these machines operate at the landing. Shown below is a Link Belt stroke delimber. Note that it has already limbed the tree and is bucking off the log (chips flying from the bucking chainsaw).
Stroke delimbers are quite expensive, often costing over $350,000 (U.S.) if bought new. However, when handling limby and small stems, they are quite cost effective compared to hand fallers doing the limbing and bucking. However, these machines can handle logs up to 30 inches in diameter, so are not just restricted to small trees.
As can be seen, stroke delimbers grasp the tree at the butt end, extend the boom and sharp knives/arms conform to the bole and cut off the limbs as the stroke arm extends. There is a bucking saw that tops the tree at the minimum preset diameter. The bole is then drawn into the machine and a calibrated wheel/gear determines when the right log length is reached and the bucking saw does its work. Log lengths are quite precise.
For mor einformation on stroke delimbers and their role in logging, see: