sawmill, installation or facility in which cut logs are sawed into standard-sized boards and timbers. The saws used in such an installation are generally of three types: the circular saw, which consists of a disk with teeth around its edge; the band saw, which consists of a hoop of flexible metal that runs over pulleys and has teeth along one edge; and the log gang saw, which consists of saw blades separated by desired distances in a frame that oscillates as a log is fed into it. Logs are fed to gang saws through pressure rollers that ensure straight cutting. With other saws the log rides on a conveyor or carriage. Provision is made for placement of the log in a new position for each cut, by the worker who rides the carriage or by the one who operates the saw. Recently it has been discovered that a jet of water at a pressure of several thousand pounds per square inch is capable of cutting a log at a rate comparable to that of sawing. Despite the fairly exotic hardware necessary for this method, it reduces the kerfs, or widths of cuts, thus wasting less material, and it does not produce the flammable dust created by sawing. In sawmills that use their waste as raw material for wood pulp, logs are passed through machines that remove their bark prior to sawing. A large sawmill may have a capacity of several hundred thousand board feet per day.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.