TREE DOZERS

Evening Post, Volume CXXVII, Issue 118, 22 May 1939, Page 11

TREE DOZERS

ORIGIN OF PLANT

TO CLEAR CATTLE RANCH

USE IN DOMINION

The origin of: tree-dozing tractordriven machinery, recently demonstrated to a gathering of farmers and engineers on the West; Coast, is explained in the April number of the "Scientific American." The treedozer, the angle-dozer, and other near relations were designed for a particular purpose, in the clearing of. the great King Ranch, the size of a kingdom, in Southern Texas, only a year or two ago, but such remarkable results were achieved that the designs have become world standards.

The King cattle ranch, running down to the Gulf of Mexico and the Mexican border, is mesquite country. What mesquite is, Zane Grey and all other cattle land novels do not exactly say, but it sounds tough, and apparently it is. There are two forms, the "Scientific American" states. One grows as a tree, 15 to 20 feet high, with a heavy and tough trunk and a great root system, and the other is a running mesquite, low growing above a dense mat of roots* just below the surface. Together the mesquites take absolute charge of vast areas in Texas, Mexico, and thereabouts.

Mexican hand labour was used on the King Ranch to keep the land open and to expand 'the grazing areas, but even at low labour costs the. balance was on the wrong side. Tractors and winches were tried to drag the standing mesquite out, but results were not economical. One'of the ranch managers got down to hard thinking. He sketched a great pushing, ripping, cutting tool that would literally tear the heart ,out of the mesquite jungle, leaving it clear for the planting of grass foods for the herds. The job required not only power, but traction, something that could crash through the jungle, push over trunks two feet in diameter, disregarding uneven or soft footing. . PUSHER AND CUTTER. ! From his sketches came the tree dozer, mounted on a 95 h.p. caterpillar tractor. It has two independent parts. One is a pusher bar carried ahead of the tractor, arranged so that it can strike the tree trunk from eighteen inches to seven feet above the ground; the other is a cutter, very much like the standard bull-dozer blade, but only three feet wide, with a heavy, keen cutting edge. In operation the tractor ■" plunges into the bush. The pusher bar strikes the trunks first, bending them forward and exposing the roots. The cutting edge below "follows through," striking at the roots of the bent mesquite and quickly gouging out the growth. In 6700 hours of working on the King Ranch one tree dozer cleared 10,000 acres of mesquite-tangled land. The cost of operation was "under two dollars an acre. ,•••■■ Running mesquite was defeated by a tractor-driven knife-rooter, no more nor less than a huge hoe, with a tenfoot blade, drawn eight or ten inches below the surface. The ranch has still vast areas of mesquite land, to be cleared, under contract, at the rate of 25,000 acres a year for the next four years. USE IN NEW ZEALAND. Only a few people sa.w the West Coast demonstration, though no doubt there will be further demonstrations and probably large-scale practical clearing operations on land that is too expensive to clear by axe and stumping methods, but which would give a payable return were it cleared economically.

A cinematographic record was made of the West Coast demonstration, and it is proof complete that this machinery does clear, bush land, scrub, undergrowth, second growth, and forest trees oi up to three feet in diameter.

The heaviest tree tackled during the demonstration was a white pine, three feet six inches through at the ground. It stood up to the first attack, and the populace chortled. From that angle the cutting blade could not rip at the roots, but an opposite attack had that white pine flat and ready for the hauler in under two minutes; trunk, stump, and roots.

The cinematographic record covers one short day's working, from stand: ing bush at 10 a.m. to cleared, drained (or at any rate with the drains in the running), fenced, and seeded in the afternoon. No great area was cleared, for it was purely a demonstration, but each section of the work was done in minutes, as against hours by any other method, and at a cost (upon a large scale) of pence as against pounds.

One of the minor machines shown in the film is a poster and, poler: this machine, a power-driven auger, digs a post or pole hole four or five feet deep, and hoists and places the pole in under five minutes, and because of its tractor feet can work as a hauler and digger on country that is properly tough for hand workers.

Several screenings of the film have been made for Ministers and members of Parliament who were unable to attend the demonstration.