Publication: Electrical Doings
New York, NY, United States
THE PORTLAND LONG DISTANCE
The work of utilizing the great water powers of the far West is progressing rapidly. Within the past year several electrical plants for the transmission of power from waterfalls over long distances have been installed, one of the most important being that at Portland, Ore. This plant was installed by the Portland General Electric Company, which owns the water power of the falls on the Willamette river at Oregon City, twelve miles above Portland, which, with a head of forty feet, has a capacity estimated at 50,000 horse-power. Part of the power has already been utilized by numerous factories and mills erected near by, and in addition to these an electric station erected some years ago has supplied current for lighting the streets and dwellings of Portland and for operating an electric street railway between Oregon City and Milwaukee, seven miles away, the direct current and high frequency alternating systems being used.
The station is located on the west side of the Willamette river, opposite Oregon City, and is being put up in sections. Twenty sections will complete the building, five are already built and foundations are now being laid for the remainder. The ultimate generating capacity of the station will be 12,800 horse-power. The station building is of concrete, stone, iron and brick, and when finished will have a length parallel with the river of 364 feet. The water is taken from the canal on one side, led through an extensive hydraulic installation and discharged into the river below on the other side. The water wheel plant consists at The present time of three units, each consisting of a pair of vertical cylinder gate improved Victor turbines, from the shops of the Stillwell-Bierce Smith-Vaile Company, of Dayton, O., one wheel being forty-two inches and the other sixty inches in diameter. The larger wheel is brought into service only at periods of excessive high water which the records show occur once in every five years. The smaller wheel runs at a speed of 200 revolutions per minute, and the larger at 100 revolutions per minute; both turbines are set on the same level, and the shaft of the larger wheel carries a pulley. The upper end of the forty-two inch wheel shaft is provided with a coupling for connecting it with the shaft of the dynamo, which is mounted above it, as shown in Fig. 1. The generator shaft carries a pulley in line with that on the shaft of the larger turbine, so that the smaller turbine may be uncoupled and the generator belted to the larger of the two wheels. When the smaller turbine is operated alone the belt lies upon a shelf surrounding the pulleys.
The weight of the vertical shaft with the armature is about 33,500 pounds, and to carry this a system of extra bearings is introduced, one of the ring-thrust type and the other a hydraulic oil bearing, both supplementing the ring bearings on the armature shaft. They are enclosed in cases filled with oil delivered by hydraulic pressure, and are surrounded by water jackets. The length of the generator shaft is twenty-nine feet, and it is eight and three-eighth inches in diameter.
Both wheels in each section are controlled by hand wheels and .both are regulated by the same governor. The belt tightener is also controlled from either floor by a hand wheel. Water is admitted to the penstocks from the upper canal by means of a head gate operated from a platform