Niagara Falls 100.000-Hp. Development

Niagara Falls 100,000 Hp. Development [41 bed of the river. One of the towers so placed was a full-strain angle tower. At the substation end of the line three two-circuit strain towers were used in order to provide for the proper distribution of the circuits at the substation FIG. 55—CROSS-SECTION OF TERMINAL BUILDING FROM WHICH LINES RUN TO ECHOTA wall. As may be observed the line comprises six three- phase circuits, each consisting of 500,000-circ.mil stranded medium-hard-drawn copper. At present two circuits are used for each 32,500-kva. unit at 12,000 volts, but clearances are provided for 88,000 volts. At 44,000 volts each circuit will have a nominal capacity of one unit of 32,500 kva., and at 88,000 volts each circuit will, if necessary, easily handle the output of three such units, or 97,500 kva. At 88,000 volts, therefore, the capacity of the six circuits will be 585,000 kva., or, roughly, 600,000 hp. It is believed that this is by far the largest capacity for which a transmission line was ever constructed. Owing to the fact that this line passes through the business portion of a busy city, special precautions were taken to guard against failure. Although the ultimate strength of each conductor is over 20,000 lb. (9,000 kg.), they are strung for a maximum tension under worst conditions of wind and ice of only 6,000 lb. (2,700 kg.). At strain towers double-strain insulators are used hav- ing a strength approximately equal to that of the con- ductor. Short spans, not exceeding 350 ft. (105 m.), were used as a further contribution toward safety and stability. The line is insulated with Jeffrey-Dewitt suspension- type insulators, two units being used in suspension strings and three in strain. Each of the insulator units was tested electrically to flash over at not less than 90,000 volts and also to a mechanical tension of 8,000 lb. (3,600 kg.). On the canal section, because of the peculiarities of the right-of-way, it was impossible to avoid a number of small angles, at which points suspen- sion strings with hold-downs were used. Insulator clamps, strain yokes and other miscellane- ous insulator hardware were furnished by the Locke Insulator Manufacturing Company. The line is protected against lightning by five over- head ground wires. On about half the line, where no corrosive fumes from chemical plants were to be ex- pected, »-in. (9.6-mm.) galvanized Siemens-Martin steel- strand was used. For the second half, where the line passes in close proximity to the chemical plants, j-in. copper-clad wire was used for this purpose. At the terminals of the line, at the terminal building and the Echota substation, the lines are first dead-ended on steel towers at some distance from the building and then looped to eye bolts embedded in the building con- struction, which is especially reinforced to withstand the tension of the conductors. The proposal to mount the heavy towers on canti- levers along the bank of the canal came from R. L. Allen of the Archbold-Brady Company of Syracuse, to whom also is due the excellent and pleasing design of the towers. The company named furnished the towers for the entire line. Clearing House for Five Stations To Handle Output of Installations with Combined Rat- ing of lf.00,000 Hp. Many New Ideas Have Been Incorporated—Unit Layout Employed By J. ALLEN JOHNSON Electrical engineer Niagara Falls Power Company WITH the completion of the new develop- ment and following the consolidation of the Niagara Falls Power Company, Hy- draulic Power Company and Cliff Electri- cal Distributing Company under Hydraulic Power Com- pany control the Niagara Falls Power Company (con- solidated) controls five generating stations having a combined rating of slightly over 400,000 horsepower. These are as follows: Hydraulic Plant—Station No. 3 (A.C.) ..... 90,000 H.P. Hydraulic Plant—Station No. 3 Extension .... 100,000 Niagara Plant—Power House No. 1........... 50,000 “ Niagara Plant—Power House No. 2.......... 60,000 Canadian Plant .......................... 110,000 “ 410,000 H.P. The map Fig. 53, shows tne locations of these stations and also indicates the network of lines by which they are tied together and to the distributing center at Echota. The Echota substation of the Niagara Falls Power Company is intended to serve three functions—(1) to subdivide and distribute the power from the new plant, (2) to serve as a clearing house for the output of the five generating stations, aggregating 400,000 hp., and (3) to act as a future stepdown transformer station. Inasmuch as the primary function of this station is to distribute the power of the new plant, it was decided to preserve the unit arrangement in its construction. The station was accordingly laid out in units of a nominal capacity of 32,500 kva. Five of these units were constructed, three for the new plant and two for interconnection with other generating stations. A con- trol building containing the switchboard apparatus was also erected. The general wiring diagram shows the arrangement of the main circuits; the physical layout of the structure is similar to that of the diagram. The general scheme is that of a main tie bus running length- wise of the building with the unit lateral buses joining HKMK