yarder

A yarder is a stationary or mobile logging machine equipped with one or more powered winches and a complex rigging of steel cables, used to drag felled logs across difficult terrain to a central collection point called a landing. The machine itself typically sits on a stable base, though mobile yarders ride on tracked or wheeled carriers. The operator works from a cab with hydraulic controls that manage the tension and speed of multiple cable lines running out into the cutting area, often hundreds of meters away.

The standard yarder configuration uses a main line (which pulls the log), a haulback line (which returns the rigging), and a lateral line (which positions logs sideways). Larger operations may run systems with two or even three independent winches. Wire rope diameters range from 16 mm for light thinning work to 32 mm or more for heavy old-growth timber. Winch motors are typically powered by diesel engines ranging from 75 to 250 horsepower, depending on the terrain slope and log volume being moved.

Yarders excel on steep slopes where ground skidding with wheeled machines becomes impossible or ecologically damaging. A ground-based yarder sits at the landing; a swing yarder (or lateral yarder) can rotate its boom to reach logs across a wider arc. Aerial designs suspend the carriage above the forest floor entirely, minimizing soil disturbance but requiring precise rigging and expert crew coordination.

The work demands constant attention to cable tension, rigging angles, and load weight. Broken cables under tension can whip across the forest with lethal force. Rigging crews must position chokers (cable loops) around logs and ensure clear paths to avoid hangups. Poor visibility from the landing, combined with the inability to see loads swinging through dense trees, creates blind zones where accidents happen.

The term yarder originated from the yarding process itself, the gathering and moving of logs from stump to landing. In North American timber vocabulary it is distinct from a skidder, which drags logs on the ground using traction, and a forwarder, which carries logs in a suspended load. High-value timber operations in steep country, particularly in the Pacific Northwest and parts of Scandinavia, depend on yarder systems as the standard method for bringing wood to roadside.