Stop saw engines, pull cutting bars from cuts, and run to safety as tree falls. Appraise trees for certain characteristics, such as twist, rot, and heavy limb growth, and gauge amount and direction of lean, in order to determine how to control the direction of a tree's fall with the least damage. Saw back-cuts, leaving sufficient sound wood to control direction of fall. Clear brush from work areas and escape routes, and cut saplings and other trees from direction of falls, using axes, chainsaws, or bulldozers. Measure felled trees and cut them into specified log lengths, using chain saws and axes. Assess logs after cutting to ensure that the quality and length are correct. Determine position, direction, and depth of cuts to be made, and placement of wedges or jacks. Control the direction of a tree's fall by scoring cutting lines with axes, sawing undercuts along scored lines with chainsaws, knocking slabs from cuts with single-bit axes, and driving wedges. Trim off the tops and limbs of trees, using chainsaws, delimbers, or axes. Select trees to be cut down, assessing factors such as site, terrain, and weather conditions before beginning work. Maintain and repair chainsaws and other equipment, cleaning, oiling, and greasing equipment, and sharpening equipment properly. Insert jacks or drive wedges behind saws to prevent binding of saws and to start trees falling. Tag unsafe trees with high-visibility ribbons.