The particulars concerning a number of cable roads are given in the table appended to this article, The construction of the :Market Street Railroad in San Francisco possesses many points of interest. The foundation for the road-bed and track rests upon concrete piers extending to a depth of 10 ft. or more below the surface of the street. These piers have a width of 5 ft„ and are 10 in. thick, and are placed about 9 ft. apart, The track and tube of this road are made into a single rigid structure by connecting the rails and slot-irons by yokes, and uniting the whole by employing con crete. The main tie or yoke connecting the opposite rails is formed of old railroad ¶-rail, bent in proper shape head down. It embraces the tube, and has fast ened to the ends suitable chairs or plates, to which the rails are scoured. From the lower part of the curved yoke extend upward two supports for the slot-irons. The lower ends of these are sufficiently separated to form the necessary width for the tribe. Tie-rods connect these supports with the main yokes through the chairs. The two rails, slot-irons, and yoke are then all connected rigidly together as one. Car and dummy are united in one vehicle, 84 ft. long over all, and supported on two four-wheel pivoted trucks. The rear truck carries the track-brake, which is between the wheels on each side. In addi tion there are the usual wheel-brakes. The forward truck carries the grip and hand levers. A rod connects the rock shaft of the track brakes with the hand lever on the forward truck, The grip in use on this road is worked by a lever, and 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, and carries the lower jaw, while the inner frame, which slides up and down upon the outer one, car ries the upper jaw, the quadrant, the operating lever, and adjusting mechanism, and is held in place by guide plates extending across the inside frame, and between which it slides. The frame carrying the jaws passes through the slot directly down alongside the cable without offset. The grip-bar, on which these parts arc mounted. is secured and supported by a frame on the running gear or truck, and not on the car itself. The car body therefore can be mounted on springs without any of the spring motion being imparted to the grip, and through it to the cable. In the way in which this grip is arranged all the parts liable to get out of order are accessible, and it is not necessary to provide pits in which to examine them.
When the car is at a standstill the cable passes along over the chilled-iron 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 ear, he draws the hand lever 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 lengthwise 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 inner frame, it rests on the moving cable, and pushes or presses it tight on the rollers before pressing it on the lower die. Uradual motion is thus imparted to the car, without jerk or jar. A still further downward motion of the upper (lie forces the rope. or cable, onto the lower die, the cable being thus 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 ear. The action of the brakes then stops the car.
The heavy traffic and the great length of the cables on these lines have rendered necessary the use of cables 11 in. in diameter, which are larger than those first used. Their weight is
about. 21 lbs. per ft. The rope runs 21 hours per day, at a speed nr about 8 miles per hour, the rate of speed for the cars, including stoppages. timing about 7 miles per hour•. Every 30 ft. along the road is a grooved supporting pulley, 15 in. in diameter, over the flanges. These pulleys are the rope-carriers. Over each of them is a plate, which may be removed to allow of oiling, etc.
In switching to and from the branch lines, it is necessary to release the cable from the grip while in motion, the car then passing, around the curve and switching onto the cable of the other line. In switching from the main to one of the branch lines, in case the gable has not been released by the grip, a safety apparatus, working automatically, closes the switch and compels the car to keep on the main line, when the eau• is stopped and backed on to the branch line, thus avoiding accident to both grip and cable. Al the termini of the various lines, turn-tables 31 ft. in diameter. having Iwo sets of tracks laid thereon, are provided for turning the cars, and are revolved by the power of the moving cable. At the water-front terminus, where the ears of all the lines concentrate, extra tracks are laid converging into the main track, and the cars of the various lines are run upon their respective tracks, as the table rotates. The speed of the table at this point is so increased as to meet the dispatch required. There are three power stations on the lines of this railway. A plan of the main station is given in Fig. 4.
The form of grip used on the Chicago City Railway is illustrated in Fig. 5. The parts of the mechanism are as follows : A, grip lever ; lever handle ; lever rod ; lever dog; E, lever dog spring; quadrant ; upper 0. ad justing head ; lower G, ad justing shoe; • II, lever screw ; I, ad justing screw; J, grip links ; K, grip beam; L, grip shank; .111, grip plate; .N upper jaw; 0, lower jaw; P, spools : Q, roller journals; R, grip rollers ; R, cable.
The Los Angeles Cable Railway is one of the longest in the world, having about 21 miles of single track worked from three power stations. The gauge is 3 ft. 6 in.. and the rails, which are of steel, 40 lbs. to the yard, are carried on iron sleepers, The channel in which the cable travels is made of cement concrete, and the slot rails on the top are of steel, and weigh 40 lbs. per yard. The works on this line are of considerable interest, and include three viaducts, while the curves are numerous. One of the viaducts carries the line over the Southern Pacific Railway Co.'s yards. A remarkable feature about it is that the road is supported on single columns, and is believed to be the only instance in existence where two tracks are thus carried, although in certain parts of the elevated railway structure in New York a single track is thus supported. The length of this viaduct is 1,535 ft., of which 50 ft, at each end are occupied by concrete approaches, and the remaining 1,435 ft. represent the length of the metal work. The viaduct affords no thoroughfare except for the cable ears, and in fact no other vehicles could travel over it, as the roadway is all open work. The height from the ground to the rail level is 25 ft. U in., and the width between hand rails is 25 ft. The riding span is 50 ft., but there are two spans of 53 ft., three of 40 ft.. one of 30 ft., and one of 20 ft. The main trusses are of the Warren type. 4 ft. deep. and weighing 100 lbs. per running ft. There are two curves on the viaduct, each of 60 ft. radius to the center line, and at these points there are braced posts to take the strain, and the tracks are also carried on double posts at these points, as well as at the approaches, as a precautionary measure.