Radially sawn timber. : Star-sawing - a new method for produring timber with vertical annual rings.

This work presents a new method of sawing to produce pith-free timber with vertical annual rings and without juvenile wood. The method, which is called star-sawing, gives sawn timber with two different shapes, viz, conventional timber with a rectangular cross-section and timber with a triangular cross-section. The volume yield for star-sawing has been determined with the help of computerized simulations and trial sawings. The results show that star-sawing is best suited for logs with a top diameter greater than 200 millimetres. Both a high volume yield and suitable dimensions of the sawn timber were then obtained. The volume yield of timber with vertical annual rings in star-sawing is about 0.70 calculated with regard to the top cylinder volume under bark