SAWMILL

machine or plant with power-driven machines for sawing logs into rough-squared sections or into planks and boards. A sawmill may be equipped with planing, molding, tenoning, and other machines for finishing processes. The biggest mills are usually situated where timber can be brought by river or rail, and the design of the mill is affected by the mode of transportation. Waterborne logs float into the mill and are dragged out in turn by a winch. More space is necessary for storage in the rail-borne system; an overhead crane serves the stockyard and carries the logs to the machines. Cutting is performed on various large machines, a preliminary operation often being that of crosscutting to convenient lengths. Reciprocating saws, band saws, or circular saws cut the log into various thicknesses as it moves past the saw on a feeder table. The log frame is a machine with a set of vertically reciprocating blades, suitably spaced; it divides a log into boards at one pass of the table. The number of blades employed may be as few as 4 for cutting thick pieces or as many as 50 for thin boards. Resawing machines handle material partly broken up, such as flitches (longitudinal sections of log) and deals (boards). The sawdust and chips from the machines formerly were disposed of by pneumatic ducts ending in the boiler house, where they were used as fuel; substantial quantities of these materials are now fabricated into particleboard and chipboard.