Head saw
Encyclopedia
A head saw, framesaw, gang saw or head rig, is the saw that makes the initial cuts in a log at a sawmill
Sawmill
A sawmill is a facility where logs are cut into boards.-Sawmill process:A sawmill's basic operation is much like those of hundreds of years ago; a log enters on one end and dimensional lumber exits on the other end....

, turning a log into cants, or planks, of wood.

History

The original powered head saw was composed of long, narrow blades that used an up-and-down motion, a reciprocating saw
Reciprocating saw
A reciprocating saw is a type of saw in which the cutting action is achieved through a push and pull reciprocating motion of the blade.The term reciprocating saw is commonly assigned to a type of saw used in construction and demolition work...

. Each blade was set at a fixed width meaning each log was cut identically, regardless of flaws. This design was not energy efficient and around 1860 sawmills began to adopt the more efficient circular saw
Circular saw
The circular saw is a machine using a toothed metal cutting disc or blade. The term is also loosely used for the blade itself. The blade is a tool for cutting wood or other materials and may be hand-held or table-mounted. It can also be used to make narrow slots...

. In the 1870s, the limitation of log size due to the radius of the circular saw was improved with the introduction of the double circular saw- with one blade atop the other. In the 1880s, the band saw
Band saw
A bandsaw is a power tool which uses a blade consisting of a continuous band of metal with teeth along one edge to cut various workpieces. The band usually rides on two wheels rotating in the same plane, although some small bandsaws have three wheels. Bandsawing produces uniform cutting action as a...

 was introduced and was able to allow the head saw to handle logs of nearly unlimited size, ideal for the Californian redwoods
Sequoiadendron
Sequoiadendron giganteum is the sole living species in the genus Sequoiadendron, and one of three species of coniferous trees known as redwoods, classified in the family Cupressaceae in the subfamily Sequoioideae, together with Sequoia sempervirens and...

.

Modern use

Today, head saws are mostly used for cutting logs 16 to 72 inches in diameter depending upon the type of band mill the saws are mounted on. More optimized machines now cut the smaller diameters since they are far more efficient and can provide greater production.

Dependent upon the log diameter, head saws can cut a log at speeds ranging from 1 to 300 feet per minute. Generally, log carriage speeds are adjustable for optimal performance.

Operation

A head saw is operated by a head sawyer. The sawyer positions the log to the proper position for the initial cut while sizing up the log determining optimal usage. The offbearer is responsible for removing the cut boards.
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