ELECTRIC BAIL WAYS. 774 ELECTRIC RAILWAYS. with the conduit. The most notable eotuluit elec- tric railway systems of the United States arc those of >.'ew York City and of Washington, D. C, the New York system aggregating over 100 miles of line in 1900. .STOR.kGE - B.TTERY .Systes(s. Numerous at- tempts have been made to operate electric rail- way cars by means of storage batteries carried in them, but in 1000 there was but one storage- battery line in operation in the United States, this being the Thirty-fourth Street Crosstown line in New York City. Perhaps the most nota- ble experiment of several made with storage-bat- tery traction in the United States was that car- ried nut on the Fourth Avenue Railway in New York City in 1890. Fourteen cars were equipped with 110 cells each, 55 on each side of the car. tmder the seats, and were run between the Post- Office and the charging station at Eighty-si.xth Street, about five miles. The result of these experiments led the officers of the road to con- elude the system impracticable, owing to the great cost of depreciation of the batteries. Al- though the use of storage-battery cars cannot be said to have reached any great degree of practical success, this device has come to have an important use for another purpose. This is the institution of storage batteries of large size to act as regulators in connection with the trol- ley or third-rail system of propulsion. Such batteries have been installed on a large scale on some of the largest street-railway systems of the United States, notably the Metropolitan Traction Company's conduit lines in New York City and the South Side Elevated Railway in Chicago, 111. Electuic LocoiioTivES Axn Heavy-Traij? Sys- tems. There are two distinct methods of oper- ating heavy trains by electric power, viz. the electric locomotive pulling trail cars and the multiple- unit system. The electric locomotive has taken two forms in practice: (1) the loco- motive proper, and (2) the locomotive car. The locomotive proper resembles the stea7n locomotive, with .such modifications as are permissible with electric motors, and is subject to the same limi- tations as the steam locomotive, in which there are concentrated in a simple unit the weight and power necessary to handle the trains. Space forbids the mention of the various electric loco- motives which have been built. Mention sboiild, however, be made of the Ileilmann locomotive, because of its unique character, and of the Gen- eral Electric Company's locomotive for the lialtimore and Ohio, and Buffalo and Lockport railways, because they are typical of the most modern .American practice in this class of nia- ehinery. In the H'cilniann locomotive the trucks carried boiler, engines, dynamo, and motors — an electric-power plant on wheels — and the question of transmission was entirely eliminated. This was the onl}' locomotive of this type ever con- structed. In the Baltimore and Ohio locomotive there are two four-wheel trucks, each truck being equipped with two motors, and the weight on the wheels being 192,000 poimds, or Ofi tons. Some of the principal dimensions are: Gauge. 4 feet S^^; inches: diameter of drivers, G2 inches; length over all, 3.5 feet; height above rail, 14 feet ,3 inches; wheel-base of each truck, 6 feet 10 inches: width, fi feet 10 inches: width, 9 feet OVi inches; drawbar pull, 02,000 pounds. Each motor has an output of 020 horse-power, or a total of 1440 horse-power for all four motors. These locomotives are provided with sand-boxes, automatic air-brakes for drivers and trains, air- whistle, and all the controlling equipment neces- sary for performing the duty of a standard steam locomotive. One of these locomotives has pulled a train of 1900 tons weight and one of 500 tons weight at :^5 miles jier hour. The Bull'alo and Lockport Railway is 18 miles long, and is regularly ojicrated by two locomotives siniilar in all rcsiwcls to the Baltimore and Ohio locomotives, except in dimensions and de- tails. The illustration shows the most modern form of electric locomotive as used on the .Metro- politan Railway of London, England. The locomotive car consists of a car-body of the usual form, arranged to carry passengers, with one or both trucks ^-quipped with motors. This ty])e of locomotive car was used on the famous Intramural Railway at the Columbian Exposition at Chicago in 1893. and is now em- ployed on one of the Chicago elevated railways, and on the electrically equip]icd lines of the New York. New Haven and Hartford Rjiilroad, the Brooklyn Bridge Railroad, and some of the London underground roads. With these cars overhead-trolley transmission is used sometimes and sometimes third-rail transmission. The :Multipi.e-Unit System of train operation is of more recent development and is descriljcd by the inventor, Mr. Frank J. Sprague, in the following words: "A semi-automatic system of control which permits of the aggregation of two or more transportation units, each equipped with sufficient power only to fulfill the rccpiirc- ments of that unit, with means at one or more points on the unit for operating it through ,a secondary control, and a train line for allowing two or more of such units, grouped together with- out regard to end, relation, or sequence, to be simultaneously operated from any point in the aggregation." This system has been installed on the elevated railways of Chicago, Boston, Brook- lyn, and New York. Cextral-Statiox Equipment. No set rule- can be made for the proper design, construction, and equipment of a power station : the object to be sought, in such case, is to generate and dis- tribute the power at the least cost. Generally, the power station should be located, if possible, about the centre of the line, and sufficient power should always be installed to have ample reserve in case of necessity. The size of the power sta- tion depends upon the number of cars to l)e run and the grades to be surmounted. Under ordi- nary conditions, the amount of jKiwcr installed in a power station should not be less than 40 horse- power per car for roads operating ten cars or less. Large roads find that an installation of 20 hor>.e-power per car is usually sufficient for all pur])oses. Cars and Motors. One or more electric mo- tors geared to the car-axles and a controlling switch on each platform constitute the principal parts of a motor-car equipment. Instead of having the journal-boxes attached to the car- frame, as in horse-cars, the motors and running gear are attached to a car-truck, on which the car-body rests. The icmarkable improvement which has been made in the design of streetcar motors within the last ten years is the principal cause of the success of electric railways. The
