These are also known as twisted grains or wandering hearts. They are caused by the twisting of young trees by fast-blowing winds. The fibres of the wood are twisted in one direction only which causes problems while sawing. However, they may be used as poles or posts without any planing (Fig. 10.4).
Figure 10.4 Typical twisted fibres and upset timbers
Upset
It is also called as rupture. This is caused due to some injury during the growth of the tree. It may be caused due to heavy winds and due to faulty felling of the tree.
Rind Galls
Rind means bark, and gall represents abnormal growth. Thus, rind galls are peculiar curved swellings formed on the body of a tree. These are caused due to the growth of layers over the injuries left over after improper felling of trees. The timber taken from this part is very weak and is not durable (Fig. 10.5).
Figure 10.5 Rind galls
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