Page:Popular Science Monthly Volume 88.djvu/888

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��Popular Science Monthly

��and of the Victoria Park Commission of Niagara Falls, they had to obtain permission from Albany, since the bed of the river is owned by New York State, and from Washington, since the water is owned by the Federal Govern- ment.

But the restrictions did not stop here. The engineers were cautioned against erecting a cableway which would cross the tracks of the Niagara Belt Line Railway, and they wer^ further warned against dam- ag i n g the cliffs on either side of the Wh i rl pool. To increase their difficul- ties they were forbidden to build any towers or s t r u c tu res which would rise above the level of the tracks of the railway run- ning along the cliff.

This first cableway o f its kind in

���Heavy rock excavation at Thompson's Point. Whirlpool appears below

��America was built at a total cost of sixty thousand dollars, exclusive of engineering expenses and exclusive also of the car and loading platforms, both of which were built in Spain. With past experience to guide them, the promoters have no doubt a duplicate installation could be built for forty-five thousand dollars.

The Torres system is simple in the ex- treme. It consits merely of six par- allel carrying or track cables which hold the passenger car, each cable be- ing securely attached to a fixed anchor- age at one end of the line and to a coun- terweight system at the other. The cables are fastened at Colt's Point to a seven hundred and forty-one ton con- crete block, and at Thompson's Point each is attached to a ten-ton counter- weight or stretcher after passing over a grooved sheave. These counterweights move freely up and down in steel guides,

��as the load is diminished or increased. Thus, the tension upon the cables is not increased by the weight of the car, although the deflection of the cables is, of course.

In other words, a sudden load thrown upon the cables causes the counter- weights to rise and the cables to sag. The greater the load on the cables the greater will be the sag. But the tension will not be increased ; it always will be ten tons to the cable. Thus, the tension

in the track cables d e- pends solely upon the counter- weights and not at all up- on the weight of passengers borne by the car.

Suppose a

Cable Should

Snap ?

For this reason the suddenbneak- ing of any one track cable would not be serious, as the other cables would support all the weight of the car without any increase in their tension. Should a cable break, the car filled with passengers would fall suddenly and then bob up and down until it assumed a new position of equilibrium. The breaking of two cables at the same time is considered impossible by the engineers.

The simplicity and safety of the Torres system lie in the fact that each cable is put into fixed tension from the start of operations, that this tension never va- ries, that the resistance of the cable can be verified at any time by increasing the load on the counterweights, that if any cable or fastening is faulty it will probably break when heavily weighted for trial or inspection trips, and that if a cable does break practically no extra strain is put upon the other cables.

The passenger car is propelled by a traction cable fastened to a ten-ton

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