After passing through the control switches, this 3,000volt direct current is conducted to the feeder and trolley lines, and thence through the pantagraph for the operation of the locomotive. Each locomotive is equipped with two pantagraphs, one located at each end. The pantagraph performs the same functions as the trolley pole on the ordinary electric car. A strong steel cable, called a catenary, runs just above the trolley wire and parallel to it all the way, and from this catenary the trolley wire is suspended by hangers at short intervals. In ordinary trolley construction crosswires strung between twin poles are the only support for the trolley wire. But in the catenary type, single poles each bearing a bracket support the catenary, and the catenary supports the trolley wire. While bracket construction is used on straight track, cross-span construction is employed on sharp curves and in the yards. The trolley wires, of which there are two, are of 4/0 size. They are especially made for high-voltage electrical power use, and are the largest diameter copper wire employed for this purpose. This form of construction permits the collection of heavy current through the twin contact of the pantagraph with the two trolley wires, and assures sparkless collection under all speeds. Under normal conditions, forty-two immense electrical locomotives are required to haul freight and passenger trains over the electrified mountain districts. These locomotives each cost approximately $112,000; they weigh 284 tons each and will haul 3,200-ton loads trailing up a one per cent grade at an average speed of sixteen miles an hour. Similar electric locomotives geared for greater speed will haul 800-ton passenger trains over the same stretch of road at a speed of about twenty-five miles an hour, and on a level stretch at a speed of sixty miles per hour. The wood-burning loco motive of fifty years ago weighed twenty tons and had a tractive power of only 5,000 pounds. The present day Mallet steam locomotive has a tractive power of about 80,000 pounds, and the electrical locomotives weighing 284 tons have a tractive power of 85,000 pounds. These electrical locomotives are 112 feet, 8 inches long, and are driven by separate motors, twin-geared to each of eight pairs of driving wheels. The cab extends for nearly the whole length of the locomotive. Regenerative braking is a method used on down grades, by which the train, instead of consuming electricity, actually produces it while traveling onward, and by which, at the same time, the speed of the train is kept under perfect control. This is the first use ever made of direct current regenerative braking, and the more clearly to explain its functions, the following is quoted from an authority on the subject. Electric motors are reversible in their function; while they absorb electrical energy and give out mechanical energy going up grades, they can reverse this operation and absorb the mechanical energy given the train down grade by gravity and transform it into electrical energy. Thus the electric locomotive provides a perfect braking system, independent and separate from the air brakes, which are used only in emergency and for stopping trains. Electric energy so generated can be turned into the trolley wire to assist other trains. In actual operation, at the crest of the grade, the helper locomotive is brought to the front of the train and coupled with the forward locomotive, the two being operated as one. The train is then controlled on the down grade by regenerative braking. This system of braking provides maximum safety, eliminates wheel, brake-shoe, and track wear and overheating, insures uniform speed on down grades, and returns electrical energy to substations to be utilized by other trains. From twenty-five to fifty-two per cent of power is thus recovered. New York Central A short description of the construction work in the Electric Zone of the New York Central will give an idea of the plant and equipment which the operating organization has to look after. The description is taken from an article appearing in the Engineering News during the construction period. The headquarters organization is indicated in Figure 2. FIG. 2.-Construction Organization of Electric Zone and New York Terminal, New York Central Railroad A map of the region over which the New York Central's terminal improvements extend is shown in Figure 3, in which heavy full lines have been used to indicate the divisions over which the electric operation has been installed, while other New York Central divisions are shown by heavy broken lines. Croton-onHudson on the main line or Hudson Division, and North White Plains, on the Harlem Division, are the terminal points of the electrical zone. Each division is four-tracked to these points, with two suburban tracks on the outside and two through tracks in the middle. On each division the suburban tracks are connected by a loop at the northern terminus. All tracks are equipped with a third rail, located outside the track. Electric current is supplied to the electric zone from two generating stations, one located at Port Morris, Borough of the Bronx, New York City; the other at Yonkers, N. Y., on the Hudson Roadway and Trackage.-The arrangement of tracks and conductor rails is exhibited in Figure 4, which is a cross section through the standard four-track roadway. The feature of prime interest is the conductor rail, an under-running protected third rail. The conductor rail is a bullhead rail, seventy pounds per yard, supported at intervals of eleven feet by cast-iron gooseneck pedestals, which are fastened each by three three-quarterinch lagscrews to a long track tie. A two-piece porcelain insulator block, molded so as to surround completely the upper head and the web of the rail, is clamped in the pedestal and supports the rail. These insulators are six inches long, projecting one and one-half inches on either side of the pedestal, which is three inches wide; a forged strap, fitting over the block, holds it in place in the pedestal. Between insulators the rail is surrounded by a built-up wooden sheathing, whose cross section is similar to that of the insulator. Thus the live rail is protected along its entire length, leaving only the lower head of the rail projecting from the insulating sheath. Protection against interruption of service by sleet, ice, and snow has been aimed at in this design as well as protection to persons. FIG. 4.-Cross Section through the Standard Four-Track Railway At some special locations an overhead conductor is used in place of the third rail. In approaching such sections an auto |