Page:Popular Science Monthly Volume 88.djvu/564

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��Popular Science Monthly

���A track surfacing and tamping gang on the New York Central. The compressor car is mounted beside the track to furnish compressed air to the tampers

��Tamping Railroad Ballast with a New Air-Tool

A GOOD roadbed is one of the greatest assets of a railroad. There is almost as much difference between riding over a well and a poorly main- tained roadbed as be- tween jitneying over an asphalt and a cob- ble pavement.

Tamping the crushed- stone ballast under- neath the ties is partic- ularly difficult. For- merly tamping was done by hand with the aid of a pick or a long bar with a blunt end. Now, many of the pro- gressive railroads use a novel type of pneu- matic tamper. In tun- nels and terminals, where compressed air is employed for operating electro-pneu- matic signals, it is simple to connect the tools with the compressed-air pipe line by means of a hose. For work out on the road, where a supply of compressed air is not available, air is supplied by a small engine-driven compressor, mounted on a special car. The gasoline-engine also drives the car.

An interesting feature of this car is the method of quickly derailing it and placing it beside the tracks. Four small wheels are set at right angles to the main wheels. By placing a few lengths

���The men generally work in pairs on opposite sides of the ties

��of timbers under these wheels, the car can be run oft" the track in a few seconds. Electric railroads employ a similar type of compressor-car, with an electric mo- tor instead of a gasoline engine to run the compressor.

The pneumatic tamp- ing inachine works on much the same princi- ple as the familiar pneumatic riveter. A piston or hammer de- livers eight hundred sharp blows per minute on the end of a tamp- ing bar, which is in- serted in the nozzle in the lower end of the tool and which is locked in position. The bar cannot be knocked out, yet the operator can shift it from one position to another. The tampers are usually worked in pairs on opposite sides of the tie. The face of the tamping bar presses against ballast beneath the bar under and to the center of the tie. This actually lifts the tie and track as much as may be desired, and packs the ballast tight. The blows are light ; consequently the ballast is not broken as much as with hand tamping and less damage is done to the ties.

The New York Central found that its savings by changing from hand tamp- ing to pneumatic tamping amounted to over $150 per mile of track.

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