Project Description Electron Hydroelectric Project, Electron Washington
The plant was designed to operate on the differential in bead between the forebay pond elevation and the elevation of the turbines located in the powerhouse. According to plans, water is diverted from the Puyallup River about 0.6 miles below its confluence with the Mowich River and carried a distance of 10.1 miles by means of a wooden flume to the forebay. Additional water is utilized by means of smaller flumes that divert water into the main flume from a number of creeks which once included Neisson and Kellogg creeks. From the forebay, located on a high plateau overlooking the powerhouse, plans called for the discharge of water by means of woodstave and steel penstocks into Pelton waterwheels housed in the powerhouse below. The turbines were designed to operate under a head of 872 feet and a total flow of 400 cubic feet per second. Total plant capability is 26.4 megawatts.
The diversion dam and intake, which serve to divert and control the river flow into the flume, were located at the upper end of the flume at approximately the 1,600-foot elevation. The dam was originally constructed as a low timber crib dam, 200 feet long and 5 feet high, covering the bed of the river longitudinally for a distance of 60 feet, exclusive of the downstream apron.
Built upon an impervious bottom of clay, the dam was made watertight by the installation of three rows of triple lap sheet piling set into the hardpan bottom and embedded in concrete. The dam was faced with 6x12" timber and covered at the crest with 1/4-inch boiler plates. In addition to the 30-foot-wide spillway which confined scour at the intake end, the whole dam was designed to operate as a spillway. The intake was set at right angles to the dam and constructed of concrete masonry. This was built 62 feet wide at the river bank and was protected by a screen grating made of iron. A steel frame was erected across the intake for the insertion of needle boards, used to regulate or shut off entirely the flow of water through the intake. A radial gate was also installed at the junction of the masonry intake and the flume for the purpose of quickly controlling the amount of water delivered to the flume.
At its lower end, the flume terminated in a reservoir that was situated on the plateau overlooking the powerhouse and the Puyallup River. The reservoir was constructed by removing material from the higher side of the site and using it to form an embankment on the lower side of the reservoir. This was accomplished by first building a trestle and piling material over it. The trestle was gradually buried until an embankment was formed. The material was from a glacial boulder formation of clay-like consistency which required blasting before it could be handled with a steam shovel. The material puddled well and formed a watertight fill which set hard, almost like concrete.
The reservoir covered an area of 12-1/2 acres and, at the time of construction, had a capacity of 6,000,000 cubic feet. To remove glacial silt carried through the flume, an 8-foot sand pump having a maximum capacity of 30 cubic yards of solid matter per hour, was mounted on a scow. The pump was driven by a 40 hp induction motor and pipe mounted on pontoons which carried the discharge over the reservoir bank. A settling basin was eventually built about halfway between the headworks and reservoir. This was put into operation in 1941. Before the settling basin was built, it was necessary to have three shifts a day running the pump to keep the reservoir from filling with silt. Now, only one shift is used to run a 125-hp motor-operated pump.
The flume entered one end of the reservoir and originally continued to a point where it discharged into a concrete basin located in front of the forebay. This allowed the reservoir to be emptied for inspection or cleaning without interrupting the delivery of water to the powerhouse. The flume now terminates at the edge of the reservoir and empties directly into it.
The forebay structure, divided into eight separate gate chambers leading to the main penstocks, was constructed of concrete. Iron racks or screens with stop boards were installed at each gate to permit inspection or repairs of the forebay structure. Although the forebay was originally built to house eight main penstocks, only four were ever installed.
The upper portions of the four main penstocks, originally constructed of woodstave pipe covered with concrete, were carried through the reservoir embankment from the forebay. The four woodstave pipes joined four steel penstocks approximately 345 feet below the embankment where surge pipes were also provided. In 1984, the woodstave portions of the pipes were replaced with steel. In addition to the lower portions of the main penstocks, a similar but smaller penstock, used to supply water for two exciters, was also made of steel. The penstocks were furnished by the Risdon Iron and Locomotive Works. These five penstocks were each approximately 1,700 feet in length and followed the incline at an average of 30 degrees from the top of the plateau to the powerhouse located on the riverbank below. The larger penstocks were built of steel 1/4-inch thick at the top and 3/4-inch thick at the lower end; the diameter of the pipes tapering from 4 feet at the top to 3 feet at the bottom. The smaller penstock for the exciters bad an 18-inch diameter. This smaller penstock was taken out of use in 1982 and, presently, static exciters are used. The penstocks were anchored by concrete abutments, designed to drain all surface water away from the pipes. After construction, the pipes were also protected with backfilling of earth, on which was planted quick-growing vegetation.
The powerhouse, built into the bank of the river on a foundation of bedrock and piling is of concrete, brick and steel construction. It measures 90x150 feet and is divided into a generating, transformer and switching house. One end wall of the powerhouse was constructed of corrugated iron to allow for future expansion with the intention of doubling the capacity. This expansion never occurred, and the powerhouse remained with the original installation of four units. Each unit consisted of two overhung Pelton waterwheels (10 feet, 6 inches in diameter), mounted one on each end of the shaft of a 5,000-horsepower, two-bearing General Electric generator. The Pelton waterwheels, which were the primary turbines used in Pacific Coast development, were reported to be the largest of their kind at the time of their installation, while the General Electric generators were second in size in the United States only to those installed at Niagara Falls. The generating units were arranged parallel to and along the river side of the building; the penstocks being brought to the river side of the building; the penstocks being brought to them under the main floor from the rear. The transformers were grouped in isolated rooms of concrete in the basement of the switch house; the switching apparatus and wiring being in compartments overhead.
The Electron Project utilized long-distance power transmission, a characteristic unique to Pacific Coast hydroelectric development at the turn of the century. Two parallel transmission lines originally ran a distance of 22 miles from the powerhouse to Bluffs, a station on the line of the Puget Sound Electric Railway, located approximately 9 miles northeast of Tacoma and 25 miles southeast of Seattle. From Bluffs, one line ran to Seattle, for the most part, parallel to the transmission line of the Puget Sound Electric Railway. The other line, which extended to Tacoma, also paralleled that of the Puget Sound Electric Railway.
A private right-of-way secured from the powerhouse to Bluffs contained two pole lines, which ran 50 to 80 feet apart. The minimum length of poles used was 45 feet, with a minimum top diameter of 10-1/2 inches. The standard spacing was 125 feet on straight lines and 90 to 100 feet on curves. The main crossarms, measuring 5x7 inches by 7 feet, 4 inches, were made from fir. These were boiled in raw linseed oil, a common practice at the time, which gave the crossarms a longer life than untreated arms. At the top of the pole was a 5x7xl8-inch arm.
The main arm supported two insulators and the top arm one insulator, giving an equilateral triangular spacing of 72 inches between wires.
Presently, a single 115 kV transmission line leaves the Electron Project and ties into the Electron Heights substation located approximately one-half mile away. From this substation, two 115 kV lines head in a northerly direction to the White River transmission substation located approximately 16 miles to the north. These lines are called the White River-Electron Heights #1 and #2 lines. A 55 kV line leaves the Electron Heights substation in a northeasterly direction and passes through Buckley to the Krain Corner Substation near Enumclaw. This line is called the Electron Heights-Krain Corner 55 kV line. A 115 kV line also leaves the Electron Heights substation in a westerly direction and ties into the Blumaer substation located approximately 34 miles away in Tenino. This 115 kV line is called the Electron Heights-Blumaer 115 kV line.
Flume Construction
The water-gathering network of the Electron Project utilized a 10.1-mile-long wooden flume, with additional smaller flumes feeding the main flume. The main flume, which conveys water from the dam to the reservoir, was first put into commercial operation on April 14, 1904. Built on a uniform grade of approximately seven feet to the mile, the flume consisted of a framed flume box built on trestle work. The supporting trestle work was of bents spaced 16 feet between centers. Additional bents were later added, making the spacing eight rather than 16 feet between centers. Typically, each bent consisted of rough-sawn mudsills of fir resting on cedar mud blocks. The mudsills supported three timber posts, on top of which rested a bent cap. These components were fastened together with iron dowels, and sway bracing for lateral support was provided by diagonally positioned planks.
The description given above is of the standard bent. In many cases where the hillsides were steep, cripple bents, or bents in which each post had a separate foundation, were used; and where the height was over 40 feet, double deck bents were used.
The bents were spanned with six 6-inch by 12-inch by 13 feet sawed stringers on edge, the ends of which lapped on each bent and which were fastened to the bent caps with 5/4-inch drift bolts. After additional bents were put in place, making the spacing eight rather than 16 feet between centers, some half-length, 9-foot stringers were used to replace some of the 18-foot stringers.
The flume box consisted of 6-inch by 6-inch by 9-feet posts bolted at the bottom between two 4-inch by 8-inch by 14-feet sills and held together at the top by a cap that is notched to take the post. Braces extended from the post down through the outer end of the sill, where they were fastened by two 3/8-inch by 8-inch square spikes driven through the sills on either side. These frames were originally spaced four feet between centers and lined on the inner sides with tongue and groove siding, the first five boards being 2-1/4-inch by 12-inch and the upper boards being 2-inch by 12 inch. The box, originally constructed only five boards high to a height of 5 feet, was raised in 1905 to a height of 8 feet. The bottom of the box consisted of 2-inch by 12-inch boards, surfaced on one side laid rough side up, with 1-inch x 12-inch boards surfaced on one side laid rough side down with joints broken. To prevent leakage at the corners, a 3-inch by 3-inch strip with heavy tarred felt was placed along each corner and spiked in place.
A train track of standard gauge was laid along the top of the flume for inspection and maintenance purposes. This was constructed of rails supplied by the Illinois Steel Company, Joliet Works, dated 1890. Hand cars were originally used along this track until gasoline-powered vehicles, called speeders, were introduced in 1910. Maxwell engines with a reversing box were used in the original engine-driven speeders. Saxine speeders with friction drive were later used. Crews would normally be carried along the flume in engine-powered speeders and then used band cars that were pushed or pulled manually at the work site. Most speeders were constructed in the shop at the forebay. Later, these were installed with 4-cylinder Ford or 6-cylinder Chevrolet engines. A specialized bent maintenance machine was constructed and used in the 1970s.
A standard gauge incline cable railway, built on a 68-percent grade, was constructed for hoisting materials and workers to the reservoir. The lower end was located near the powerhouse and the upper end near the reservoir. This was taken out of operation on June 22, 1971, after the cable car broke away from its line and smashed at the bottom of the hill, killing Clarence A. Bransteitter, who was one of 19 workers returning from work in the car at the time.
A series of spillways constructed at intervals along the flume facilitated the drainage of water from the flume box for shutdown or repair. The last spillway, located near the terminus of the flume at the reservoir, employed needle boards which could be used to control the amount of water engineering the reservoir.
Sixteen landings were also constructed along the flume that were used as areas to store supplies for flume maintenance work. Some of these were covered and served as eating areas for flume workers.
Flume Maintenance
The flume was originally framed with 9-foot-high posts, although the box was only built up to a height of 5 feet. In September 1905, side boards were added to the flume box, raising it to a height of 8 feet. This box then remained in use until the late 1950s.
The flume right-of-way passes through steep, heavily-wooded hillsides, commencing at approximately the 1,600-foot elevation on the south side of the Puyallup River. As timber was not cut to a sufficient distance from the flume, problems arose during the first two years of operation by trees falling or sliding onto the flume. In 1905 and 1906, timber was cut back to give adequate clearance. To carry out this work in a manner that did not endanger the flume, trees were cabled either at the bottom or on the top before being cut. For trees cabled on top, it was necessary for men to climb up 75 to 150 feet and place the cable around the tree at that point. These trees were left to rot, lying on the hillside behind stumps and other obstructions. From time to time, it was necessary to remove some of the felled trees to prevent them from sliding into the flume.
A great deal of flume maintenance work was required in the early years of the project. In 1909, the flume box began to show signs of stress, and extensive repairs were begun to strengthen the framing. Eight thousand additional frames were added, making the spacing between frames in many places 2 feet instead of 4 feet.
The greatest item of expense during the first years of operating the flume was the maintenance of the structure. This was primarily due to poor foundations. In places, the substructure was built on clay that became soft and crumbled away due to flume leakage. In other places, the substructure was built upon dirt from cuts which, like the clay, would crumble from continuous leakage. Breaks in the flume occasionally occurred where the flume crossed canyons and draws. The bents were sometimes built on dirt foundations rather than rock. In these draws, the dirt would often slide, after being softened by rains or melting snow. Most of the breaks that occurred in the first ten years of operation happened between bents #500 and #1900, which are in the section of flume located on the steepest terrain.
In 1910, a program was started to install additional bents every 8 feet. Substructure maintenance problems arose from using hemlock, which deteriorates rapidly when exposed to the weather. In 1910 and 1911, many of the hemlock posts were replaced. Where hemlock bent caps were used, additional bents had to be constructed on either side of the defective ones.
In 1911 the operating superintendent, C. E. Quinan, and the superintendent of water power, J. Harrisburger, and others suggested that the flume be rebuilt. S. L. Shuffleton prepared a report in August 1911, in which he proposed rebuilding the flume, constructing settling basins and reservoirs using tunnels in places, and increasing the capacity of the plant. Shuffleton's plan, however, was never implemented.
Over the years, there has been a continuous maintenance program to replace the bent structures as needed. To accomplish this, it required a crew of approximately 40 to 50 men. Generally, the maintenance followed a five-year rotation plan from one end of the flume to the other. In a single year, the crew would replace from 700 to 900 bents. In April or May, one crew would dig out the foundations of the bents to be replaced, and another crew tore out the old bents. A finishing crew would then put in new mudblocks and prepare the foundation for the bent. A crew called the "donkey crew" would put in the new bents, which required jacking and shimming, A sway brace crew would sway brace the new bent posts together. Finally, a brush crew would clear the right-of-way, burning brush and old bents, and salvaging the reusable bents. Maintenance work also includes removing ice from the flume during the winter, stopping leaks, fighting fires, and removing moss.
A number of major slides occurred through the years which took out large portions of the flume. The first major slide occurred in 1932 just below Neisson Creek. In 1933, 150 to 200 feet of flume were taken out by a landslide near Kellogg Creek. In 1934, 300 to 320 feet were taken out by a landslide near an area called Lions Head Rock, just below landing #16.
In 1933 a diversion of water from Neisson and Kellogg creeks was discontinued. Several smaller flumes, however, still diverted water into the main flume.
On November 23, 1936, a slide destroyed the powerhouse. This incident was described by Emmot Chase, a lifetime employee who was born at the project and lived on the hill above the powerhouse:
The slide did not destroy the foundation, which remained intact, with the four turbine generator units damaged but still in place. Units No. 1 and No. 2 were repaired and returned to service in 1937. while Units No. 3 and No. 4 were returned to service in 1941.
After the slide of 1936, the flume box was reconstructed in two phases. The first 16,000 feet out to bent #1002 were rebuilt in 1938. The remaining 38,000 feet were replaced in 1941. In this rebuilding of the flume box, the two sections replaced in 1933 and 1934 were not rebuilt, but the new box was joined to these. The boards matched to the exact dimensions. These two sections were subsequently replaced in 1951.
At the time the flume box was reconstructed, a settling basin was installed about halfway between the headworks and the reservoir was approximately 1,700 feet long and 100 feet wide at the widest point and 15 feet deep. A discharge gate was provided at one side for the removal of silt. Water can be diverted through the settling basin or the settling basin can be entirely bypassed by diverting water down the flume.
Other slides occurred in 1943 and 1964 which carried away approximately 200 and 130 feet of flume, respectively.
In 1929-30, Puget Power started a program of wood treatment. This consisted of soaking wood in a vat containing creosote. When the flume box was rebuilt in 1938, arsenic was used in place of creosote. In the 1960s, pentachlorophenol took the place of arsenic as the wood preservative used.
In the late 1960s, a program of lining the inside of the flume box with plywood and plastic was undertaken. This may have actually increased the rate of deterioration of the box by trapping moisture between the plywood and siding. However, this reduced the leakage of the flume box and thus reduced the washing out of the foundations. As a result, the overall life of the flume was increased.
In the summer of 1984, a program of rebuilding the entire flume was undertaken. This rebuilding was accomplished in two phases, approximately four miles in 1984 and the remaining six miles in 1985.
While the configuration and operation of the project remain essentially unchanged, new materials have been used in the flume construction. Steel stringers and frames replace the wooden ones used previously. New stringers are connected at either end and are staggered in a manner that allows for removal of the bent with water in the box. The new stringers are bolted to the existing bent caps. Prefabricated steel frames are welded to the stringers and spaced with 4-foot centers. The flume box planks are bolted to the steel frames. Planks with splines are used in place of tongue and groove. A new rail track has been laid on top of the steel frames. The substructure for the most part has been left intact, although a number of wooden bents were replaced with steel bents. Through the course of normal bent maintenance, all wooden bents will be converted to steel bents.
Baugh Industrial Contractors, Inc. was contracted for the demolition of the old flume box, replacing bridges and construction of steel stringers and frames. Approximately 150 to 160 men were hired for these activities. National Erectors was contracted for the installation of the new wood liner. Approximately 60 to 70 men were employed in this work.
The flume rebuild was carried out by several crews working in sequence, each having its own responsibilities. The first crew consisted of three workers responsible for removing the old rail from the top of the flume box. A second crew demolished the upper three-quarters of the flume box, leaving the floor and a stub side wall intact. A specially-adapted backhoe operating from the floor of the flume box pulled the caps of the frames off. Chain saw crews made horizontal cuts through the side posts, while other sawyers made vertical cuts up to the top of the side board. The backhoe operator would then grab sections of the sidewalls and cast them off to one side of the flume. A third crew removed the bottom of the flume in 4-foot sections. This same crew removed the old stringers and placed the new stringers in temporary positions (new stringers were pre-stocked in the old box prior to start of construction). A fourth crew would level the existing caps on the old bents and then arrange the stringers in their permanent positions. A fifth crew welded the stringers together and lug-bolted them into the caps of the old bent. A sixth crew installed the new frames and new rail. Seven frames and two 30-foot lengths of rail would be set out. The frames were then welded to the stringers and the rail bolted to the top of the frames. After being welded in place, the frames were cabled for additional stability. The next load would have eight frames and two 30-foot lengths of rail, Loads were taken out on flatcars by speeders along the new rail and installed by means of a carry deck crank positioned at the end of the new rail. A seventh crew was responsible for putting the flume floor in. Vinyl was clamped to the steel frames before the floor boards were bolted onto the steel frames. The eighth and ninth crews were responsible for putting in the side boards. Again, vinyl was clamped to the steel frames before the side boards were bolted in place. Wood splines were used at the top and bottom of each side board and a steel spline at each end. A sealant was also used at the end of each board to help initially seal the boards until they swelled from water. Wedges were placed between the top of the side wall plank and the frame to help press the wall against the floor. Another crew worked independently on rebuilding bridges where the flume crossed draws.
