Democratic Sentinel, Volume 16, Number 3, Rensselaer, Jasper County, 5 February 1892 — HOW THE CABLE CAR MOVES. [ARTICLE+ILLUSTRATION]

HOW THE CABLE CAR MOVES.

f*®cts tliat Are Not Known to the Average Reader. The endless cable laid in conduits under the highway for street cars is

really the invention, in its primitive form, of one J. C. Stewart, of Philadelphia, as early as 1854, but was never put into practical use until Mr. Andrew S. Hallidie, of San Francisco, perfectled the system, and with his associates

built the Clay Street Hill Railroad of San Francisco in August, 1873. The system, says Harper’s Weekly, consists simply of an endless wire ropeplaced in a tube (having a narrow slot from one-half to three-quarters inch wide) beneath the surface and between the rails, maintained in its position by means of sheaves, rollers or wheels. The rope is kept continuously in motion by a stationary steam engine at either end of the line or at any convenient point between the two extremes. A gripping attachment''at the end of a vertical steel rod connected with the car and passing through the narrow slot in the tube transmits the motion of the cable to the car.

The speed at which the car moves is determined by‘the rapidity of the cable and this is regulated by the revolutions of the driving-wheel at the stationary engine. The rope is made of steel wire about three inches in circumference, is supported every thirty-nine feet on eleven-inch sheaves, but does not run directly under the slot, but to one side of it, to prevent sand and drift from falling on the rope and to enable the foot of the gripping attachment to pass by and under the upper sheaves and over the lower sheaves in the tube.- The connection between the cars on the street and the traveling rope is by means of this gripping attachment, as shown in the illustration. The grip is worked by a lever and is the one now generally employed by all the companies. It is formed of two frames, one sliding inside the other. The outer one is secured to the grip bar on the forward truck by bolts, aud carries the lower jaw; while the inner frame, which slides up and down upon the outer one, carries the upper jaw, the quadrant, the operating lever and the ad- . usting mechanism, and is held in place by guide plates extending across the inside frame, and between which it slides. The frame carrying the , aws passes through the slot directly down alongside the-cable without offset. The grip bar, on which these parts are mounted, is secured and supported by a frame on the running gear o r truck, and not on the car itself. When the car is at a standstill the cable passes along over the chillediron grooved rollers at each end of the

lower die. The lever operating the grip is then inclined forward. When the gripman desires to start the car he draws the handover back. This action moves the inner frame downward, carrying with it the upper jaw or die. This die consists of a piece of brass secured in the lower end of the sliding part. The lower die is a shorter piece of brass fitted length-, wise between the two? rollers. This is arranged with set-screws to be raised to take up wear. The upper die is longer than the lower, and as it is

forced down by the in- amp and lever. ner frame it rests on the moving cable and pushes or presses it tight on the rollers before pressing it on the lower die. Gradual -motion is thus imparted to the car without jerk or jar. A still further downward motion of the upper die forces the rope or cable on the lower die, the cable thus being held tightly between the dies. A reverse motion of the lever raises the frame and upper die and releases the cable and allows it to run through freely without imparting any motion to the car, which is then brought to a standstill by the action of the brakes.