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Show BIG TIBER TRACT WILL BE UTILIZED Three Billion Feet to Be Cut in Forest Above Arrowrock Dam. VALUE IS $36,000,000 Equipment Devised to Overcome Over-come Engineering Problem Prob-lem in Shipment. Special to The Tribune. BOISE, Idaho, Sept. 12. Above Arrow-rock Arrow-rock dam in the basin of the Boise river it is estimated that there is 8;000,000r000 feet of merchantable timber. Sawed into lumber worth, ray, $12 a thousand, this would represent a value of $36, 000,000. It is owned by the United States government, govern-ment, the Boise-Payette Lumber company com-pany and a number of others with smaller smal-ler holdings. This timber is to be cut in the immediate imme-diate future, driven down the Boise river and converted into lumber at the mills, fourteen miles below the Arrowrock dam and just outside the city of Boise. Here at the big dam. then, is presented a knotty little problem to lift these logs from the reservoir, carry them over the crest "60 feet above the bed of the river and deliver them In good condition in the stream betow. Problem Is Overcome. Nothing would be permuted, of course, to interfere with the main object of the dam the impounding of water for the 1!40,000 acres of rich soil in the Boise valley. val-ley. But as t he dam racks the water for a distance of eighteen miles, converting convert-ing the river channel into a reservoir, and including both branches of the stream, it provides ideal means for the driving of logs. It was early agreed that some scheme must be devised for lifting them over the dam. TJnder the direct supervision of Engineer Engi-neer Charles M. Paul, his assistant. Walter Wal-ter R, Young, designed an equipment based on principles used where scientific logging Is done. This has a maximum capacity of 60.OO0.O00 feet for the period of sixty days In summer when the water in the reservoir is within forty -five feet or less of the top of the dam". At this rate it Is est i ma ted Thai it will take fifty years to lift over the entire 3.000,-000.000 3.000,-000.000 feet. Equipment Is Effective. By this equipment, located at the extreme ex-treme southern end of the dam. logs of any sine or length will be taken out of the reservoir hy means of a cable lift and deposited on the concrete deck on the top of the dam. From this dek thev win be fed by a stop and loader to power-driven power-driven spiked rolls, on at a time, the speed helng under the control of the operator. op-erator. These rolls will rarrv the logs across the dam and turn therri over to a bull-chain with sours or teeth in ore- vent sliding. The chain win tak them down a -e per cent slope at a speed of MRhty-feet a minute and dis'-harire them into a gravity chute, through which thev "111 slide into the river below. Structure Is Substantial. As this structure must wit list and the elements for mnny years, it Is bull I nf the beat of concrete and steel, It Is unique in gos ertthfenl construction. Power for its operation Is now developed by the evprnment at the diversion dam. twelve miles below. Later a power riant is to be established at Arrowrork. immediately imme-diately under the dam. This dam. the highest In the world. 348.6 fet from th bottom of tb fmmda-tinn fmmda-tinn to the crest, is tn be dedicated with a harhp -lie and harvest home in Roisc on October 4. It la finished more than a year in advance of the time specified al the bRtnninE and at a coet of 2,000000 less than the stlmates B storing water this season, the driest In histnrv. R saved the crops np K'OOftO srres and practlcallv naid for itself. |