Sawing of Timber, Cutting of Timber

Saying of Timber may be defined as 

“To cut the logs into various formations into pieces is called sawing.”

Purpose of sawing

The logs (trees after felled) if not cut for a long time would results in circumferential shrinkage because of drying of moisture from the outer most part and less dryness in the inner part. i.e. the outer most rings shrink more as compared with inner rings. As a result star shakes or cracks would appear on the surface of log and would narrow as one goes inwards.

 

Methods of Sawing

There are four basic methods of sawing. 

i) Ordinary sawing

ii) Quarter sawing

iii) Tangential sawing

iv) Rift or Radial sawing

Ordinary Sawing

It is the most economical, cheapest and is widely used method of sawing. In it only long parallel planks are cut. Because the inner portion is heart wood which is hard and outer portion is sap wood which is soft thus after dryness there will be unequal shrinkage, thus the planks are liable to wrap and twist. 

Quarter Sawing

In Quarter sawing the logs are cut or sawn in quarter and is then cut in such a way so as to bend in transverse direction. This method is adopted when no distinct modullary rays are present and gives very fine figure wood. 

Rift or Radial Sawing

In this method logs are sawn parallel to modulary rays and perpendicular to annual rings. This method gives least shrinkage but most wasteful. This method gives most decorative works in which medullary rays are marked, and least shrinkage is because of the property of medullary rays to resist shrinkage. 

Tangential Sawing

If annual rings are well formed and medullary rays are not well formed than tangential sawing is used. In this method cuts are made tangent to the annual rings. Planks obtained by this method wraps too much and must not be use for costly works. Such planks are not suitable for flooring. 

Felling of Trees to get Timber

This short post is a series of post on Timber structures and Timber engineering. We know that the main source of timber is trees and forests are sources of trees. Firstly the trees are felled and than the log (fallen tree) is cut in several ways called sawing.  Here are some of tips for felling of tees.

Felling of Trees

By Felling of Trees we mean the process by which the standing timber is converted into rough timber i.e. the trees are fallen down by cutting from the bottom.
Only a fully grown tree should be felled so as to yield maximum timber having maximum strength. Early felling would result in less timber. Delayed felling would cause a damaged heart wood. A tree should always be felled when it is fully grown and is matured as well.
The lower we go more would be timber but we must cut it above the ground or roots at 1 foot above the ground. The tree must be felled in summer season when no sap is moving otherwise seasoning would be a problem.

Felling of Trees

Process of Felling

The process of felling is not difficult as long as it is done by following some technical rules and methods. Some of the important tips which would be helpful are as follows;
Make a deep cut at the lower possible point of the trunk. This cut must be on the side opposite to the one in which the tree is intended to fell. A cut slightly higher one is made on the opposite side of that cut. The tree from the top is then tied with ropes on all the four sides. The tree is then forced with ropes to move down towards the appropriate side.
It must be felled gently so that it can’t be broken down or damaged.