From muscles to machines

For thousands of years, humans have used their own muscle power to bring logs out of the forest for

use as fuel, lumber, paper and other necessities. To avoid this drudgery, they are devising easier, more efficient

ways of falling trees and transporting them to the mills. The great di­versity of physical conditions found in the

world's forests means that for any situation, there is sure to be a better way of doing the job, a labor-saving

machine suited to the task.

Since water is the most readily available medium for transporting timber, the timber trade evolved in close

prox­imity to rivers, lakes and oceans. Water powered the earliest sawmills, and the best, most accessible

stands of timber were found along the rivers and streams on which the mills were built.

From the outset, men exerted their muscles and de­vised ways of getting logs into the water where they could be

floated to the mill. Until the invention of the first logging machines during the last half of the nineteenth century,

the task was approached in essentially the same manner the world over. Although systematic commercial

exploitation of the Lebanese cedar forests is known to have been well underway by the eleventh century BC,

little knowledge has survived concerning the logging methods. What can be de­duced is that no machines were

used in this work and, as is most likely, the methods employed were similar to those used for most of the next

3,000 years.

By the beginning of the Christian era, forest management was being practiced in Greece and parts

of the Roman empire. Again, the methods used to harvest timber, are not clear. The earliest records in­dicate an

almost-universal use of controlled burning to fall and buck trees, and human labor to move them directly to

where they were used, or to a nearby body of water. For example, during the twelfth century AD, a massive

timber harvesting enterprise was launched in the rugged Qin Feng mountains of China to obtain materials for

the recon­struction of the city of Kaifeng. A road was built, including a five-kilometer-long bridge, over which

timber was trans­ported in some type of wheeled vehicle. In the late-eight­eenth century a logging operation in

southern China used ropes to yard logs to a river with capstan devices turned by oxen, mules or teams of men.

Flumes and slipways several kilometers long were also built to move logs to the river, where they were floated

another 50 kilometers to the saw­mill.

Дата добавления: 2015-07-20