“TREE CUTTING TECHNOLOGY
Adapted from Encyclopedia of American Forest and Conservation History (1983) and other sources.
Tree cutting (logging) technology has undergone extensive changes in the last 200 years. When colonists arrived on the eastern seaboard, the ax was the only method to fell trees to clear farmland, build houses, and provide firewood for the hearth. Yet early settlers were faced with many problems in the New World, including the fact that the trees were very large and very tall, unlike the trees the settlers had left in Europe.
By 1789, the American felling ax evolved to meet the settlers’ needs. This unique ax was straight handled and single bitted (one blade), which gave great balance and more power to the stroke. It short, heavy, wedge-shaped blade was both durable and easily extracted from the wood. Curved handles became standard during the 19th century. Some time around 1850, loggers began using a double-bitted ax. This new invention proved to be very popular. The ax had the advantage of having two cutting edges, yet still possessed the balance and durability of the single-bitted ax. By the 1880’s, Americans were making these blades of cast steel—rather than iron with a steel cutting edge welded on.
American settlers also modified European cutting or chopping techniques. Instead of making V-shaped cuts at almost the same level on opposite sides of a tree trunk. Americans made one cut lower than the other (the undercut) and made both cuts flat on the bottom. This method gave the feller greater control over the direction the tree would fall and reduced the time-consuming use of wedges and levers.
Beginning in the 1870’s, crosscut saws were adapted to felling trees—a major innovation. Crosscut saws had long been used to cut logs into lengths once they were on the ground, but now the saws were used in the horizontal position to cut the trees down. Two crosscut saw developments helped this major advance: The invention of raker teeth, which when coupled with cutting teeth and gullets carried away the sawdust and tree pitch or sap that would often clog the saw blade. The invention resulted in a saw that could cut green standing trees without binding the blade. The other invention was the adoption of the tempered steel blade, which was stronger than previous saws and would remain sharp through hours of use. Use of crosscut saws, especially the two-man saws, spread rapidly and became the industry standard for many years. By the turn of the 20th century, new saw designs with different teeth had been developed for use on different tree species. In the 1920’s, the bucksaw replaced the crosscut saw in the Northeast and Canada. The bucksaw was lighter, but not suitable for large trees.
The springboard was introduced in the far West and in cypress logging in the South. Essentially, springboards were metal-tipped planks that were inserted into notches chopped into the tree trunks. These springboards served as platforms on which the fellers stood, allowing them to be above the dense undergrowth and above the swollen base of the old-growth trees, which were often pitch-laden and full of rotten wood.
During this period, logging operations were often along the edges of streams and rivers, making the transportation of logs downstream to the mill a relatively easy task—river log drives. As harvesting proceeded, logging operations moved farther and farther away from the river’s edge, creating a problem—how to move the heavy logs. Loggers responded by cutting smaller length logs or, in the case of redwoods and other large trees, by splitting (riving) the logs lengthwise.
Yarding or skidding of the logs also changed over the decades. The most difficult aspect was moving the logs from where they were felled to a place where they could be transported to the mill. Log moving technology progressed quickly in the United States from the human effort applied through brute force and primitive tools to oxen and horses. In the Northeast and Lake States, logs were very often hauled during the winter months when horses could easily pull heavily laden sleds over the ice and snow.
Mechanization came to the woods in the form of high-wheel logging where logs were suspended under and arch that connected a set of large wooden wheels. High wheels, as they were called, were pulled by horse or oxen, and later steam powered tractors. Beginning in the 1880’s, railroads with special geared locomotives were used to transport the logs from the forest to the mill. Three well-known gear driven locomotives were manufactured by Shay, Climax, and Heisler. Many of the first Forest Service timber sales were railroad operations. A great improvement on hauling logs to transportation sites was the invention of the stationary steam-powered Dolbeer donkey engines to yard (pull) logs from where they fell to a central location. The process was referred to as ground lead logging.
The crawler-type tractor, first powered by gasoline, then diesel engines, was used beginning in the 1920’s to pull logs along the ground or used with big wheels, arched steel axles, and A-frame logging arches. In the 1920’s, with the invention of the cable-operated blade by Forest Service employees in Portland, Oregon, the “cat” was ready to replace the donkey engine to haul logs or build roads in almost any terrain. Gasoline- and then diesel-powered logging trucks were used in the forests beginning around World War I, but their main impact came shortly after the end of World War II. Since that time almost all logging operations on national forests have used logging roads and trucks to carry logs from the forest to the mill.
Newer technological inventions, such as the high-lead logging with a spar tree, skyline full-suspension systems with one or more spar trees or towers, balloon, and helicopter operations, allowed logs to be carried high over the forest with very little dragging of the logs through the often steep, rugged country with fragile soils. Many of these new systems would become required on the steep mountainous country that was characteristic of many national forests.
The first power saw was built in the 1870’s, when the Ransome steam tree-feller was designed. What may have been the first gasoline-powered chain saw was tested in 1905 at Eureka, California. These early experiments were followed by air- and electric-powered models. Moderately successful drag (reciprocating) saws were used to cut fallen logs to length and to make short bolts for shingles. All of these experimental models proved to be too cumbersome, too heavy, and too undependable. Then in 1927, Andreas Stihl of Stuttgart, Germany, built a portable, gasoline-powered chainsaw that revolutionized the industry. But because of the Great Depression, power saws remained relatively rare until after World War II.
The chainsaw soon replaced the crosscut and bucksaws for felling trees, as well as the remaining ax work. The chainsaw also made new felling techniques possible. In the big timber country, the Humboldt undercut was used. After an initial horizontal cut on the tree trunk, a second angle was sawed up to the horizontal cut; then the “wedge” of wood between the two cuts was removed from the stump. The tree trunk was then cut from the backside along the horizontal cut on the frontside until it would fall down. This would leave the butt end of the log with a square end.
By the 1940’s, hydraulic shears appeared that could cut through standing trees when pressure was applied to heavy-duty blades. By the 1960’s, a variety of tractor-mounted shears were in use, with many machines designed not only to cut the trees, but also to remove the bark and limbs, cut the tree to desired lengths, and stack the logs. These new systems worked very well on relatively flat terrain and with small-diameter trees. Another advantage was that they could operate during either the day or night.
Other inventions have played roles in the evolution of logging technology, some of which have come into widespread use—others limited use. With increasing pressure from the Federal agencies to reduce ground erosion during and after logging operations, restricting the use of heavy equipment has become the norm. Full-suspension of logs, use of low-pressure tire-tractors, selective cutting, directional felling, and aerial removal of logs are all measures that may be required of logging companies in order to log on national forests or Bureau of Land Management lands today. In any case, the new techniques and equipment are easier on the land, usually more efficient, but also more costly.”-http://npshistory.com/publications/usfs/fs-650/sec6.htm