Valuable Karri

Sun (Auckland), Volume III, Issue 771, 18 September 1929, Page 14

Valuable Karri

OUT BY STATE ENTERPRISE

Flooring and Furniture

TIMBER OF WESTERN AUSTRALIA HELD by West Australians as of little account until comparatively recent years karri hardwood is now milled by the State in large quantities, according to Mr. E. B. Sinclair, manager of the Perth Mills, who is at present in New Zealand on holiday. The demand for this timber keeps 350 men employed at the Government mill which has a daily output of 48,000 superficial feet. Though karri is mainly used for sleepers and beams, it is becoming increasingly popular for floors and even furniture.

Karri is far and away the largest tree in the Western Australian forests, and is second only to jarrah in importance. Karri trees 200 feet high, with a length of bole of 120 feet to the first limb, are common. There are many to be found of greater height, and some years ago a karri was measured which had attained the extraordinary height of 27S feet. One of the finest specimens of the species, growing at Karridale. was destroyed some time ago. Its dimensions were 34 feet in circumference at three feet from the ground; 160 feet to the first branch; 14 feet in circumference at the first limb; over 200 feet in extreme height. From these figures it can be shown that the bole of this tree from the bottom to the first limb contained nearly 6,000 cubic feet of timber. STILL 120,000 ACRES LEFT Unfortunately, the habitat of karri is very limited. Jarrah occurs in great forests in the south-west of the State, but sparse stands are to be found over a much wider region than that of the better quality forests. Karri, however, is confined to the wetter portions of the south-west of

the State. It Is estimated that 75,000 acres of pure karri forest remain at Karridale, and tliis merges into a mixed forest of karri and marri, carrying a large volume of valuable karri, so that the area of merchantable karri forest may be regarded as 120,000 acres. Regrowth is rapidly developing at places which have been milled over during the last 50 years or so. Karri is a hard wood, varying from almost white to reddish-brown in colour -when first cut, hut -with seasoning and with age the colour darkens and the reddish-brown tint is always present. Jarrah and karri timbers are very similar in appearance, and it is often difficult to differentiate between the two. The usual test is to burn a splinter of the wood and note the result. Jarrah burns to a black charcoal, but with karri the red hot coal continued to glow until a true white ash is produced. KARRI’S MANY USES The uses of karri are numerous. The strength and stiffness of the timber, combined with the extraordinarily long, clean lengths which may be obtained, render it unsurpassable for superstructural work, and it is not surprising to learn that, of recent years, the name “karri, the beam timber,” bas been applied to this wood. In beams, rafters, columns, warehouse floor joists, and other members, where strength is the essential factor, karri gives every satisfaction. It may be mentioned that, in one of the mills in the karri forest, the roof is carried by two trusses with a common tie beam consisting of a piece of 12in by 12in karri. SO feet in length. Karri makes very satisfactory transmission line cross-arms, and is also used to a considerable extent for coach, wagon, motor vehicle and wheelwright work. For the manufacture of wooden pipes if has been found eminently satisfactory. and. after a number of years’ use, pipes of powellised karri are still giving eflicieut service in a water-

power system, although the water pressure is considerably greater than that usually considered advisable for wood stave piping. With suitable machinery, karri can be rotary cut or sliced into first-class veneer or plywood. As a flooring, karri gives excellent service and, at the State Sawmill. Pemberton, large air-seasoning stacks of this are held. At this mill also there is a case mill turning out pieces for fruit cases, the karri case with the dressed edges of its face boards being of outstanding quality. Although somewhat difficult to work on account of the hardness of the timber, kiln-dried karri boards undoubtedly make an excellent floor, for they take a high polish, and produce a surface greatly resistant to indentations and to wear. For furnishings also the timber is well suited, since it has a rich colour, particularly when kiln-dried, and an attractive figure. Suitable drying schedules for all sizes of karri have been developed as a result of tests at the Forests Department’s experimental kilns, and these are available if required. Karri is on Lloyd’s list of shipbuilding timbers, and, before the days of steamships, vessels built wholly of karri were constructed in Western Australia. At Hamelin Harbour, from which the product of the early Karridale sawmills was exported, quite a, fleet of large lighters, built entirely of karri, was employed. In shipbuilding nowadays, the wood is used largely for keelsons, and the long lengths obtainable are regarded by shipbuilders as an added advantage for this work. POWELLISATION “Powellisation,” a treatment named after the man who devised it, is designed to combat the white ant. a dangerous pest in Western Australia. From the saw the timber is loaded on trucks and piled in huge vats. When these have been sealed, a solution containing arsenic and molasses is pumped in and brought to the boil, at which point it is kept for eight hours. After cooling, the timber is ready for immediate use. The process has reudered it immune from attacks by ravaging white ants and other pests and it has the strength to stand up to any task. Mr. Sinclair was of the opinion that State control of the mills in West Australia had a steadying influence on the local prices for timber, and opened up new forests. “The industry has grown so much,’’ he added, “that in the mills of the State over 900 men are employed, with a daily pay-roll of over £SOO.”