192 



THE IRRIGATION AGE. 



great deal of material is also brought in over a rail- 

 road siding on the other bank of the river. A seam 

 of coal underlies the quarry, and an amount sufficient 

 for all purposes is mined and transported directly by 

 cableway to the dredges, hoisting engines and pumps 

 in the river, as well as to the boiler and electric-light 

 plant. 



rig. 5. 



Fig. 6 shows the Lidgerwood traveling cableway, 

 of which, at the present time, twenty are in use in the 

 work at the Chicago Drainage canal. 



way is used merely to take material from the canal 

 and deposit it in spoil bank on one side. The work is 

 usually done on abreast 12 feet high. The record shows 

 that 32 men at the breast, filling skips and chaining 

 large stones, average 14 cubic yards per man per day, 

 or 28 tons of material. Of course, it would not exceed 1 1 

 yards if it were not for the fact that a great saving of 

 time is accomplished by the handling of large 

 stones out of the pit by simply chaining them 

 to the fall block. Stones weighing six or seven 

 tons have been handled out of the canal in 

 two or three minutes, thereby makinga distinct 

 saving in cost for drilling, powder for blasting 

 and the cost of sledging ; and the mere act of 

 throwing the chain arounti a heavy block is 

 only a fraction of the cost of filling the skip. 

 On the first twelve feet of the canal the stone broke up 

 fine under the blast; on the second and third lifts it 

 breaks up so large that the work seems to peculiarly 

 fit the cableway, and a large saving is made on all 

 material that is handled out in large blocks. 



Fig. 6. Head Tower Lidgerwood Traveling Cableway. 



The span of this cableway is 700 feet; the towers 

 are 90 feet high, and are located on cars 102 feet long; 

 each one of these cars rests on twenty-seven 33-inch 

 wheels, and on this car or platform are located at the 

 head tower the engine, boiler and the required 

 amount of ballast, and on the tail tower simply suffi- 

 cient amount of ballast for its stability. 



The main cable is 2J^ inches; the engine is double 

 10x12, 50 horse power, with double drums. The cable- 



In handling large stones the danger of slipping a 

 chain or breaking a link is minimized on account of 

 the fact that the stone may be handled horizontally 

 at any height desired, just sufficient to clear the sur- 

 face of the ground if required. The usual practice is 

 to deliver these heavy blocks on the canal slope of 

 the spoil bank, and they are frequently taken out at 

 the noon hour, with only two or three men. at work on 

 extra time, so that when the men come in to fill the 



