Imperial Insulators were used on the Niagara Falls-Buffalo Transmission Line

The Niagara Falls-Buffalo Power Transmission Line.

POWER transmission between Niagara Falls and Buffalo is accomplished over a line, partly aerial and partly underground, about twenty-six miles long. The cables, three in number, which carry the three-phase current at 11,000 volts from the transformer house at the falls to the city line of Buffalo, are of stranded copper, of 350,000 circular mils cross section. These cables are bare, and are supported on triple petticoat porcelain insulators of a peculiar design, each of which was tested at a pressure of 40,000 volts before being placed in position upon the poles. At the city line of Buffalo the three aerial cables are connected to three cables of 350,000 circular mils, each rubber-insulated and lead-sheathed, which are laid in a conduit running along the canal to the transformer house of the Buffalo Street Railway Company. These cables were tested before laying under 80,000 volts pressure, and have given very satisfactory service since their installation. At 11,000 volts their capacity is about 5000 horse-power. It is anticipated, however, that before long the pressure on the transmission line will be doubled, and its capacity at 22,000 volts will, of course, be proportionately large. The conduit contains six ducts capable of eventually holding cables sufficient for the delivery of a total of 20,000 horse-power to the Buffalo Street Railway Company. At the transformer house, three of the tension mains enter through the underground conduit and are carried overhead on the walls of the transformer house to three Wood lightning arresters. The static transformers reduce the potential of the current to 500 volts at which pressure it is led, through six rubber-covered cables of 600,600 circular mils each, to the two rotary converters. These have a capacity of 400-kw each and operate at 500 revolutions per minute. They are of the six-pole type, and transform the three-phase alternating current of 500 volts to a direct current of the same pressure. The rotaries are started by means of the direct 500-volt current, and when up to speed the three-phase current is switched on. From the rotaries run a set of 750,000 circular mil cables to the distributing switchboard, which permits the current to be switched to any of the feeder circuits in the city or to be put in multiple with any of the generators in the power house. In the main power house at Niagara Falls are three railway rotary converters, each having a capacity of 650 horse-power. These receive the two-phase current at 2200 volts from the large generators and deliver current at 575 volts to the Buffalo & Niagara Falls Street Railway Company, the Whirlpool Rapids line, and the Main Street line in Niagara Falls. Two of these machines were furnished by the Westinghouse Company, and one by the General Electric Company, arid each has its own controlling switchboard. The static transformers at both ends of the long transmission line are cooled by means of fans driven by small motors. Each of them has a capacity of 1250 horse-power, and an efficiency at full load of nearly 98 per cent. The efficiency of the whole transmission line is stated to be well above 80 per cent. at full load.

A great part of the success of the line is due to the splendid performance of the insulators, which were manufactured by the Imperial Porcelain Works, Trenton, N. J. They are about five inches in diameter, and are provided with a lip at the base of the upper convex part, which conducts rain water to two small spouts situated at opposite ends of the diameter, thus preventing the dripping of water from the edge of the insulator to the cross arm. Their high resistance qualities are due to the fact that the porcelain, instead of being glazed as in ordinary insulators, is practically fused throughout the mass. The aerial construction is of the most careful description, rendered especially so by the fact that the line crosses other lines in several places. No insulation other than that due to the porcelain insulators is attempted on the aerial lines,