Theodore Roosevelt Dam, Eastern Mining Area Transmission Line (115kV System), Salt River, Roosevelt

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The Eastern Mining Area transmission line is a 130 mile loop located in the Superstition Mountains, east of the Phoenix metropolitan area in eastern Maricopa, northern Pinal and Gila Counties, Arizona. It passes through the vicinities of Goldfield, the Roosevelt Dam, Miami, Superior, and spurs off to Ray. At selected vertices, the UTM coordinates are: USGS Quad: Apache Junction, UTM: USGS Quad: Mormon Flat Dam , UTM: USGS Quad: Horse Mesa Dam, UTM: 12/ USGS Quad: Inspiration,UThf: 12/ 832 USGS Quad: Superior, UTM: USGS Quad: Teapot Mountain ,UTM: Date of Construction: Designing Engineers: Orville H. Ensign, Charles C. Cragin. Supervising Engineer: Louis C. Hill. Construction Engineers: A. H. Demerick, Irving C. Harris, William Cone.

Manufacturers: United States Wind Engine and Pump Company, Batavia, Illinois. Muskogee Iron Works, Muskogee, Oklahoma. Pacific Coast Steel Company, San Francisco, California. Present O\\rner: Salt River Project.

Source document Quoted word for word from HAER AZ-6-C. Not written, edited or summarised by this site.

The Eastern Mining Area transmission line was first built to carry hydroelectric power generated at Roosevelt Dam, the United States Bureau of Reclamation's first large scale work, into Phoenix. It soon expanded to serve the area mines the southern portion of Gila County. The sale of power to these mines provided revenue to expand the Salt River Project's hydroelectric system and furnish Salt River Valley farmers with electricity.

Source document Quoted word for word from HAER AZ-6-C. Not written, edited or summarised by this site.

Leah S Glaser, Research Archives, Salt River Project. Photogapher: James R. Eastwood, Audiovisual Photo Division, Salt River Project. Date: June THEODORE ROOSEVELT DAM, EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page 2) TABLE OF CONTENTS I. Introduction 3 II. Local Historical Background 3 III. Electrical Transmission: A Historical Overview 5 . IV. Construction of the Transmission Line from Roosevelt to Phoenix 9 V. Line Reconstruction and System Expansion 12 VI. Striking it Rich with the Mines 17 VII. Completing the Circuit: "The Loop" 18 VIII. The Linemen 22 IX. Epilogue 23 X. Conclusion 26 THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page 3) I.

Introduction The volt Eastern Mining (EMA) transmission line, constructed in segments from traverses the Superstition, Apache, and Pinal mountains east of metropolitan Phoenix in Arizona ( (see AZ-6-C-30. fhe line was first built to convey power generated by Roosevelt Dam, the Bureau of Recla.mation' s tirst large-scale work, to Phoenix and the rest of the Salt River Valley. I It soon expanded to serve the area mines in the southern portion of Gila County.

The sale of power to these mines provided the revenue to expand the Salt River Project's hydroelectric system and furnish Salt River Valley farmers with electricity (see figure The system remained relatively untouched until the when technological development and the increased use of electrical power demanded a significant frequency change. In recent years, the Salt River Project has added lines and replaced towers and portions of the system off the original right of way. Today the system is a complex multi-line network serving much of central Arizona, including Phoenix and the mining towns of Globe, Miami, and Superior. The volt EMA lines connects to the Valley's system at the Silver King and Goldfield receiving stations. 2 The development of the original line followed industry standards.

However, these transmission structures still maintain their original design integrity, feeling, and function. They stand today as representations of early long distance electrical transmission ingenuity and design. In addition, the towers also serve as a testament to the federal government's role in bringing electrical power to remote areas in order to produce agricultural products and extract mineral resources from the country's western territories. II. Local Historical Background The area surrounding Globe, Superior, and Ray first attracted gold and silver prospectors in the As these minerals became depleted, miners soon discovered large copper deposits beneath the silver layers. Initially, copper was primarily used to manufacture kitchen utensils and roofs. However.

as industrial enterprises expanded, copper became an essential material for I The history of the construction of the Theodore Roosevelt Dam is described by Donald Jackson in "Theodore Roosevelt Dam,"(National Park Service, Historic American Engineering Record, No. AZ-6), For additional information on the first few years of the Salt River Project, see Karen L. Smith, The lvfagnijicent Experiment: Building the Salt River Reclamation Project, (Tucson: University of Arizona Press, 2 Industry standards were dictated by groups such as the American Institute for Electrical Engineers (AlEE) and shared at conferences and in journal publications. THEODORE ROOSEVELT DAM, EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page conducting electricity.

When the railroad arrived in the it emerged as one of the Arizona ., ' . 3 temtory s most Important exports. Farther west, Phoenix and the Salt River Valley too had experienced tremendous economic growth. Beginning in the Mexican and Anglo settlers dug canals to irrigate lands north and south of the Salt River. These cultivated lands yielded highly profitable crops and grains. A scarce and poorly controlled water flow, however, hampered further agricultural expansion. By the late a series of floods and intermittent droughts waterlogged much of the area. In addition, as the amount of irrigated land increased, competition for the limited water supply grew increasingly fierce. The only existing process for determining water rights was through litigation.

Continuous legal challenges indicated the need for a comprehensive water storage 4 plan. On June 17, the United States Congress passed the National Reclamation Act. The purpose of the act was to utilize streams and rivers to irrigate arid lands in the western United States through large water storage projects, thus opening the way for settlement to expand the United States economy. Valley farmers responded by forming the Salt River Valley Water Users' Association to lobby for a federal water storage project. The government agreed with local surveyors that the Tonto basin site was an ideal location for a dam. On March 12, Secretary ofInterior Ethan Allen Hitchcock selected the Salt River Project to be one of the first five reclamation projects in the country.

In the government began to build Roosevelt Dam sixty miles northeast of Phoenix. A temporary power plant constructed at Roosevelt provided horsepower needed to run machinery, operate the cement mill, and provide lighting for constructing the dam. However, government officials soon realized the high potential for the commercial sale of hydroelectric power to the Salt River Valley. Although the government intended that the electricity generated at Roosevelt Dam be used for pumping groundwater, they also realized it had commercial possibilities. In Congress authorized the Secretary ofInterior to sell excess power 5 generated at federal reclamation projects, with customer priority given to municipalities.

The receipts from these power sales would go to the reclamation fund as credit toward repaying the cost of building reclamation projects. 1 Bisbee, Jerome. Clifton. and Clarkdale were other places where copper was heavily extracted. Thomas Sheridan. Arizona: A History (Tucson: The University of Arizona Press. 4 Christine Lewis, "A History of Irrigation on the Tempe Area," (M.A. Thesis. Arizona State University. 5 In The Townsite Act, Statutes at Large 34. sec. 5. 116 Congress authorized the Reclamation Service to sell surplus power not needed for irrigation purposes to municipalities. THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRi\NSMISSION LINE HAER No.

AZ-6-C (Page 5) Throughout the United States, and particularly in the west, large hydroelectric power projects capitalized on advances in high voltage, long distance electrical transmission. In doing so, rural farms and remote mining communities opened up as new economic markets. While electrical machines optimized production and reduced labor costs, electrical pumping maximized water supply and delivery. The government persuaded Valley farmers to consider selling hydroelectric power for revenue, as long as the power production did not decrease the Roosevelt Dam's water supply.6 In Secretary of the Interior James R.

Garfield agreed to the future sale of (kilowatts) generated at Roosevelt Dam to the Phoenix based Racific Gas and Electric Company (later Central Arizona Light and Power Company (CALAPCO)) for subsequent distribution to 7 the city of Phoenix and to various Salt River Valley businesses. A permanent hydroelectric plant 8 began operating in June III. Electrical Transmission: A Historical Overview When electrical power transmission was in its early developmental stage, federal auspices over public utilities was rare. At the tum of the century, most Americans considered electricity a commodity for private enterprise, rather than a government service, and thus privately owned companies motivated and determined the evolution of electrical technology.

Initially, urban centers were the power companys' primary market. 9 In the late nineteenth century, although electrical service was generally limited to the Northeast and Midwest, American companies lead the world in electrical system development. Rapid and independent innovations in electrical technology characterized the period. Scientists experimented with electricity as early as the but the invention of arc lights in the enticed commercial interest and henceforth rapid technological development. Throughout the Thomas Edison issued several licenses to various companies to utilize his discoveries. These included incandescent lights and direct current circuit equipment.

The Westinghouse Electric and Manufacturing Company, established by George Westinghouse in was his 6 David Nye, Electrifying America: Social Meanings ofa New Technology (Cambridge, MA: The MIT Press, 7 For a more thorough discussion on the Project's hydroelectric development see David M. Introcaso, "Mormon Flat Dam," (National Park Service, Historic American Engineering Record, No. AZ-14, James M. Gaylord, "Power and Pumping System of the Salt River Project, Arizona," (Phoenix: Salt River Project Archives, 1 January S For an historical overview of the Theodore Roosevelt Dam power plant and transformer house and the development of the Salt River Project power system, see Christine Pfaff, "Theodore Roosevelt Dam, Power Plant." (National Park Service, Historic American Engineering Record, No.

AZ-6-A), 9 Nye, THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page 6) strongest competitor. Because of the corporate competition and subsequent push for technological advancement, the electrical industry did not standardize its equipment and had few compatible systems. The controversy over direct and alternating current contributed to the industry's incongruity. Throughout the the most popular debate in the electrical industry concerned the best mode of electrical transmission, direct or alternating current (DC or AC). Unlike direct current, the electrical impulses in alternating current oscillated at back and. forth intervals, rather than flowing in one direction. The rate of the alternating current is known as frequency.

Frequency (measured in cycles) allowed for an increase in the force of the electrical current (voltage) and a decrease in the amount of electricity transmitted at a time. Transformers or converters stepped voltage up or down through a set of coils. This flexibility allowed electricity to travel over significantly greater distances than direct current. The AC system, however, lacked an efficient corresponding motor. The dispute pitted the Edison Company, which advocated DC, against Westinghouse which advocated AC. While American companies pioneered many forms of electrical technology, Europeans made more significant advances in the area of long distance transmission. In Nikola Tesla of Yugoslavia patented a simply-constructed polyphase AC motor.

Westinghouse secured the manufacturing rights. A multi-phase motor meant that the current experienced more than one burst of energy for every encounter with an electromagnet. This greatly increased the efficiency of the AC system. Advances in the development of AC fueled the development of longer transmission lines. By AC transmission lines served remote western mining operations like Telluride's Gold King mine in western Colorado. 10 However, the most significant advances in hydroelectric and transmission technology developed in California during a period of corporate mergers and industry consolidation. Consequently, throughout the electrical equipment became more standardized. II Vernon E.

"Entrepreneurship and the Development of Electrical Power in Southwestern 10 Colorado," Essays in Economic and Business History 8 II A three-phase circuit meant that three bursts of energy, rather than one, resulted from each encounter with an electromagnet, surpassing the efficiency of direct current for the purposes of electrical transmission. For a comprehensive description of the development of electrical transmission and hydroelectric power see Mark T. Swanson, "Santa Ana River Hydroelectric System," (National Park Service, Historic American Engineering Record, No. CA-130), THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page 7) Reclamation engineers based the design tor the transmission line from Roosevelt to Phoenix on the standards of the industry.

These included the techniques their colleagues had used to design 12 the hydroelectric systems at Niagara Falls, New York and Santa Ana, California. California's engineers and businessmen applied their knowledge and expertise to Arizona. To direct the development of A.rizona' s system, the government hired Orville Hiram Ensign, who worked for the Redlands Electric Light and Power Company when it built the first long distance, three phase, alternating current electrical system in the United States. 13 The Santa Ana line was the longest transmission line in the country at the time of its construction. It was also one of the most powerful. Built from it carried volts of electrical power down the Santa Ana Canyon for 82 miles into the San Bernardino Valley.

The ambitious project was Ensign's brainchild. One of the keys to the line's success was his development of the so called "Redlands type" insulator. Insulators encase the conductor wire and protect the other electrical equipment, including the transmission tower or pole, from high voltages. They are made of a material, such as porcelain or glass, that does not conduct electricity. Prior to Ensign's glazed porcelain design, those that could withstand voltages higher than were rare. Porcelain was much stronger than glass, and the flared-out edges (referred to as a "petticoat"), further strengthened the insulator. The arrangement of wires and insulators on the poles was also important to the line's success.

At certain intervals across the line, maintenance workers rotated and transposed wires to reduce the static noise of an 14 unbroken electromagnetic field. From to Edison Electric built a series of hydro plants on the Kern River to electrify Southern California. Former General Electric engineer James A. Lighthipe designed a 118 mile long, line. Not only was Kern River the highest voltage line in the nation, it was also the first in the country not supported on wood poles. Instead, steel towers designed by a windmill company carrIe . d t he con ductor WIres. . 15 12 The first all steel transmission line was built in from Michoacan, Mexico to Guanajuanto on forty foot towers, feet apart.

Norman Rowe, "Lightning-Rods and Grounded Cables as a Means of Protecting Transmission Lines Against Lightning," Proceedings ofthe American Institute ofElectrical Engineers (6 June 13 For a comprehensive description of the Santa Ana system, see Swanson, "Santa Ana River Hydroelectric System." 14 William A. Myers, Iron Men and Copper Wires (Glendale: Trans-Anglo Books, For considerable detail on Orville Ensign and the development of the Santa Ana transmission line, see Swanson, "Santa Ana River Hydroelectric System Transmission," 15 Until that time. the only time steel towers had been used to carry transmission lines were in special cases like river crossings. Myers, 47. THEODORE ROOSEVELT DAM.

EASTERN MINING AREA TRANSMISSION LINE HAER AZ-6-C (Page 8) Electrical engineers considered a variety of factors to determine the best tower design. These included wind, sleet, terrain, temperature, and the probability of accidents, such as breaking cables. The structures most resembling the conditions and purposes for transmission structures were windmill towers of pyramidal form. Designers of high voltage electrical lines often turned to these manufacturers to design transmission towers. 16 In Central Arizona, the terrain, wind pressure, arid weather conditions, and high voltage required the strength and stability of steel towers, rather than wood or steel poles.

A large portion (30 miles) of the transmission line from Roosevelt Dam's hydroelectric plant to Phoenix, traveled through the desert mountain region known as the Superstition, Apache, and Pinal Mountains. There, soil conditions are often loose and rocky. The surface is extremely uneven and among the most rugged areas in Central Arizona. The vegetation is typical of the Sonoran desert and includes dense areas of palo verde and mesquite trees, amidst cholla, saguaro, prickly pear, barrel, and pin cushion cactus. After Ensign assessed the topography and determined certain specifications, Reclamation officials solicited bids from various companies to manufacture the 17 towers. Local (Los Angeles based) agents represented most of the firms.

Though the designs of other towers were stronger, a windmill company from Illinois offered the 18 lowest bid at The United States Wind Engine and Pump Company was the primary manufacturer of the most popular American windmill, the Halladay Standard. In the Connecticut based U. S. Wind Engine and Pump Company purchased the Halladay \Vindmill Company and moved to Batavia, a popular center of windmill production, in the Fox River Valley 35 miles west of Chicago. Windmills made from iron and steel began to appear in the However, manufacturing steel was quite expensive and did not become commercially profitable until the tum of the century. The U.S. Wind Engine and Pump Company produced galvanized steel towers.

They marketed their products through their own descriptive catalogs, dealers, agents, or in exhibitions. Towers were sold in intervals offive feet. Braces, which ran 16 "Load" is a term used to describe various types of stresses on a structure including electrical voltage, physical pull, wind pressure, and climate. D. R. Scholes, "Fundamental Considerations Governing the Design of Transm ission-line Structures," Proceedings ofthe American Institute ofElectrical Engineers (29 June Downing, "Foundations for Transmission Line Towers and Tower Erection." Proceedings ofthe American Institute ofElectrical Engineers (20 June 17 The U.S. Wind Engine and Pump Company was represented by local agents Pearson, Roeding, and Company.

File marked "Roosevelt Dam Construction: Materials and Construction," Salt River Project Archives. 1& Ibid. Ensign was suspicious about the strength of these towers because they lacked horizontal braces. He did prefer the arrangement of pins. The final decision, however, was based on price. Their 40 foot galvanized steel towers ran each. The company was responsible for securing the appropriate insulators and crossarms for their towers. Once the price of crossarms and insulators were added to the bilL the total estimate came to still far below the other bids. THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRANSMISSION L[i\fE HAER No. AZ-6-C (Page 9) diagonally, were specially adapted for various height requirements.

While the windmill company supplied the towers, the Reclamation engineers specified parts, materials, and measurements. 19 IV. Construction of the Transmission Line from Roosevelt to Phoenix Like the Roosevelt Dam, the United States Reclamation Service also directed the construction of 2o its hydroelectric generating unit. The generating facility contained six, turbine units. This equipment generated a three phase alternating current at volts and 25 cycles, which the electrical industry considered the best frequency to operate heavy industrial equipment required by the mines.

The current then traveled to a transformer house that stepped up the voltage to for the sixty mile transmission into the Valley.21 The line from Roosevelt to the city of Phoenix ran from the dam to the town of Mesa, where it would meet the distribution system for the Valley. Additional lines continued to the Gila River Indian Reservation, and into 22 the town of Chandler as well. Louis C. Hill was the Supervising Engineer. A. H. Demerick was the electrical engineer in charge of construction?3 Most of the labor force at the Roosevelt Dam was under Demerick's supervision. A group of 35- 50 men, mostly Indians, constructed the transmission line. Beginning in six to eight men from Demerick's camp surveyed the transmission line from the Tonto Basin to Phoenix.

They completed the survey in February. Workers began constructing the transmission line from Roosevelt Dam to Mesa on July 4.; Engineers tested the completed double circuit, three phase, line in August ..A Workers were able to lay five miles of tower foundations a month. This activity took longer than originally anticipated, especially in the mountainous segment east of the Goldfield mine. 19 Ensign even made requests as to the level of phosphorus used in the steel. T. Lindsay Baker, A Field Guide to Windmills (Norman: The University of Oklahoma Press, 70; File marked "Roosevelt Dam Construction: Materials and Construction:' 20 See Donald C. Jackson, "Theodore Roosevelt Dam," (National Park Service, Historic American Engineering Record, No.

A2-6), 21 The transformer house was built in For a description on the transformer house, see Pfaff, "Theodore Roosevelt Dam. Power Plant." 22 The Sacaton project was a failed attempt to irrigate acres on the north side of the Gila River. 23 Demerick died in May of He was succeeded by both Irving Harris and William Cone, 24 Louis HilL Supervising Engineer. United States Reclamation Service (USRS) to A. P, Davis, Acting Chief Engineer, USRS, 7 February Files, Salt River Project; Arizona Republican, November 27, Newsclippings, Salt River Project Archives, THEODORE ROOSEVELT DAM, EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page 10) According to engineering practices, foundations had to have the strength to resist horizontal forces at the ground level.

This was determined by their holding power and the density of the soil. While in the open desert, tower feet were planted in five foot deep holes on plates, bricks, cement, and rocks were needed to secure them in the mountains! (see AZ-6-C-2). These materials had to be hauled over long, rough distances, The Arizona Republican estimated that 500 barrels of cement and twelve tons of anchor bolts (to which the tower frames are attached) comprised the tower foundations I(see AZ-6-C-56). Crews marked each foundation with the height of the tower required.

When the towers arrived frorp the factory in groups of varying heights, the bundles of uprights, braces, and crossarms, were numbered with a metal tag to correspond with the foundations, A wagon, or even mules when necessary, could then carry them directly to their proper locations. Workmen completed the foundations by January 25 The U,S, Wind Engine and Pump Company towers were made of rectangular angle iron braces of galvanized steel. They had four legs and two crossarms made of "channel" iron, Four wires hung across the upper arm, and two across the lower. The towers were either mounted on the concrete bases or anchored in solid rock (see AZ-6-C-35).

Legs and foundations were altered in accordance with uneven surfaces, They were single braced, unless they ran at an angle, and then they were double- braced, According to a engineering article, the tower heights were chosen "to give the minimum number and degree of vertical angles consistent with economical construction," 26 Most towers were about 35 feet tall, but heights ranged from 15 to 90 feet (see AZ-6-C-ll).

fhe tallest were in depressions, and the shortest on mountain crests (see AZ-6-C- 21 Anticipated in January the first shipment of the 600 tons of steel for the towers did not arrive from Illinois until March, The manufacturer sent the towers with numbered parts and instructions for assembly, They also pre-punched holes for brace rods and special fixtures and provided anchor rods. Despite some initial problems with less than perfect fittings, workers raised the first tower on Monday, March 2nd , and completed over half a mile in the next three days. Assembly, performed on location, required twelve men.

About half were needed to raise the towers with a gin pole (two wooden poles configured in such a way as to act like a crane) operated by horse power, a practice commonly used to raise windmill towers. On flatter 25 Arizona Republican 9 October 20 October November 8 December 16 December 17 January February March Newsclippings, Salt River Project Archives. 16 "Construction of a Transmission Line in Arizona," Engineering Record (28 January W. E. Mitchell, "Tower Foundations for Transmission Line Towers and Tower Erection: The Alabama Power Company," Transactions ofthe Annual Convention ofthe American Institute ofElectrical Engineers (20 June 17 "Construction of a Transmission Line in Arizona," THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRANSMISSION LINE HAER No.

AZ-6-C (Page II) surfaces, workers first assembled towers on the ground as suggested by both engineers and the manufacturer AZ-6-C-3. 4. 5. and On the steeper inclines, workmen built the towers from the ground up Eventually, they were raising an average of seven towers per day, with fourteen of them per mile. Soon, a shipment of barrels of insulators arrived, about half the amount required for the whole line. Manufactured by the Locke Company, they were made of porcelain, the proven material for withstanding harsh climatic conditions, in the "triple petticoat" style. The pins to the three-part, pin-type insulators were assembled on site and were cemented into the cross arms with a special frame.

Wire to conduct the electricity was tied to the insulators by two pieces of 79 cable and two brass clamps (see AZ-6-C-J 3). ~ Two work camps of20-30 men hung six-strand hemp core copper wires (knO\vn as standard No. 1 across the towers. They began stringing the line in April at the Highland Canal just east of Mesa. The top crossarm carried four wires, and the bottom carried two. Wire angles were spaced at a four foot equilateral triangle. By July workers had completed 20 miles. 3D They finished the job by November. The Arizona Republican described the process: Their mode of operation is to have a rope the required two miles in length with block attachments.

These are taken ahead two miles and one end attached to an engine at that point; then the rope is stretched back with the aid of mules to where the coils of cable are and fastened to the end of same one at a time. A pulley is placed on each tower to run the cable along on and keep it from contact with the ground. The engine then stretched it to place and the operation is repeated until all six cables are in place and they are ready to move up to the next bunch of reels ... 31 The newspaper also noted that knowing how tight to stretch wire over rough hills, so that it neither breaks nor sags too much, "takes considerable technical information and a whole lot of natural horse sense" (see AZ-6-C-8). 32 28 Arizona Republican, March Downing, "Steel Towers for Windmills," Catalog of Us.

Wind Engine and Pump Company, Windmill Manufacturer's Trade Literature Collection, Historical Research Center, Panhandle Plains Historical Museum, Canyon, Texas, 29 See footnote # 10 for an explanation on insulators. Arizona Republican, 27 March 27 May 6 July and 26 November 30 Ibid. 31 Arizona Republican, 26 July 32 Arizona Republican, 6 July THEODORE ROOSEVELT DAM, EASTERN MINING AREA TRoA.NSMISSION LINE HAER No, AZ-6-C (Page 12) Once completed, the entire line stretched 65 miles Roosevelt Dam to the Pacific Gas and Electric Company's plant in Phoenix AZ-6-C-14).

When the line reached Mesa near the Highland Canal, steel tripartite poles carried the wires, instead of towers, into the Salt River Valley, This 19 mile long branch took off from a switching station northeast of Mesa, It consisted of two, three phase circuits, At the time, Project engineers believed the line from Roosevelt to Phoenix, built according to the most up-to-date practices, was "one of the best pieces of transmission line construction of its type in existence,,,33 Yet soon after its completion, hawks decided that crossarms made attractive perches, Along with lightning strikes, they were responsible for most service interruptions,34 At first, engineers attached a cast iron guard to each tower to remedy the industry wide problem with large birds, Other problems resulted from hunters, who shot out insulators, or from people, who for reasons equally puzzling, threw baling wire across the lines, The Engineering Record featured the relatively reliable Arizona line in However, by the following year, a contract to sell power generated at Roosevelt to the Inspiration Consolidated Copper Company not only offered additional revenue to repay SRVWUA's debt to the government, but provided an opportunity to rehabilitate the line, V.

Line Reconstruction and System Expansion The Reclamation Service's contract with the Inspiration Consolidated Copper Company, signed on August 2, stipulated the construction of a new line which would run from Roosevelt Dam to Inspiration's mine and smelter near Miami, In addition to the agricultural resources in Central Arizona, the nation's economic interests also turned to the region east of the Salt River Valley for rich mineral deposits, By Gila County's Miami, Inspiration, Old Dominion, and Magma mining companies were among of the nation's leading producers of copper. 35 Although there were a number of hydroelectric sites in the West, most were too far from the mines to supply energy prior to the advancement of long distance transmission technology.

33 "Will Revise Power Line," The Arizona Republican, November 5, SRP Annual History Salt River Project Archives, 34 Ibid, 35 Copper production in Central Arizona began as early as when the Old Dominion Copper and Smelting Company began its operations at Globe. By Arizona led the nation in copper production and pretry much held that title until at least Melissa Keane and A. G, Rogge, "Gold and Silver Mining in Arizona Prepared for the Arizona State Historic Preservation December For more information on the activities of the mines, see Frank Tuck, "History of Mining in Arizona," Department of Mineral Resources, Phoenix, Arizona, THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page 13) Some mines generated electrical power with coal and steam.

Those located in the rough western regions had difficulty shipping these materials to their remote locations. Yet, the mines had many uses for electricity. Electricity lit the shafts without any danger of exhausting oxygen supplies. Wires carrying electrical current were considerably less cumbersome than pipes carrying steam or compressed air. This made some equipment, like drills and pumps, more portable and easier to maneuver in tight shafts and tunnels. Electricity drove hoists, air compressors, ventilation equipment, mills, and tramming machinery. Finally, small and powerful locomotives replaced mules for transporting mineral~ and equipment. The new energy 36 source made mines much more efficient in their production. As early as Reclamation's Superv'ising Engineer Louis C.

Hill notified SRVWUA President Benjamin A. Fowler that he had received numerous applications for power from the Globe area. Residents realized that power would allow the mining regions to develop rapidly while cutting operation expenses considerably. In response, Fowler agreed that selling power to such districts made sense. "Personally," he commented to the Arizona Republican, "I have no doubt at all that the policy of the board will be to dispose of such power as can be wisely sold without detriment to the interests of the valley..." 37 On January 8, Globe Attorney George Stoneman reported that "Globe is anxious to secure power from the dam...

I am very confident that there will be an electric line built from Globe to Roosevelt." Stoneman further claimed that Globe was booming with building improvements. The railroad to Miami was complete, the Old Dominion Mine was nourishing, property values were up, and the population was on the rise. Therefore, it was naturally the first place entitled to power following the Salt River Valley.38 Despite the compelling argument, the nearby mining town of Miami, Globe's chief competition, secured this privilege for their more profitable company. The agreement with the Inspiration Consolidated Copper Company meant a revenue stream of at least a year to the Salt River Project.

This income was extremely helpful to the Salt River Valley farmers trying to payoff their Roosevelt Dam construction debt to the government. In addition, the copper companies would pay for the construction of the new 38 mile line from Roosevelt to the Miami-Globe mining district, but the United States would own it upon completion. Reclamation officials, however, would design the line in order to ensure uniformity with the rest of the hydroelectric system that extended to Phoenix. Inspiration could 36 Nye, Frederic Quivik "Early Steel Transmission Towers and Energy for Montana's Copper Industry," J'vfontana: The lYfagazine of Western History 38 (Fall 37 Hill to Benjamin A. Fowler, 2 I December January Files, Salt River Project Archives.

38 Arizona Republican, 8 January THEODORE ROOSEVELT DAM. EASTERN MINfNG AREA TR/\NSMISSION LINE HAER No. AZ-6-C (Page 14) secure a minimum of kilowatts of power for its plants two miles east of Miami, near 39 Globe. Meanwhile, since the technology of high voltage transmission had gro\VTI rapidly. Engineers offered various solutions to common problems. As the use of electricity increased, power customers demanded larger amounts of power to be transmitted over longer distances. This required greater emphasis on the role of the insulator. By Electrical Engineer E. M. Hewlett declared that, "It has approached, if not already passed, the limits of good construction.,,4o While the "pin type" insulator had become larger to meet greater voltage demands, Hewlett and his colleague, H. W.

Buck, developed a new type of insulator more suitable for high voltages. They introduced it at the annual meeting of the l\merican Institute for Electrical Engineers (AIEE) on July 26, Suspension and strain insulators, argued Hewlett and Buck, were safer and more reliable than the pin-type. Suspension insulators hang vertically beneath the cross-arm. The strain variety, which stretched between two points, could be used at intervals to dead end the line, or anchor it at angles and curves (comparefigure #3 and AZ-6-C-13). The first designs were ten inch individual units which were flanged, or petticoated, discs to protect the bundled (known as "tie") wires, from rain. The units interlocked through the center to insulate bundled wires.

Conductor wires would pass through the discs' holes exerting pressure on the porcelain. The discs were arranged in a series so that if anyone broke, the tie wire remained intermeshed. When a conductor supported by a suspension insulator breaks, as it retreats from the breaking point, it will stop at the next disc. The conductor remains protected. Each disc could handle about volts, thus the level of voltage carried on the line determines the number of discs in a series. Hewlett and Buck suggested using these insulators with material properties (i.e. degree of moisture absorption) appropriate to the climate of the line's location. A 140 mile, volt line in California built by the Stanislaus Power Company was the first to use suspension insulators . Iy.

41 exc IUSlve 39 The transmission line's length later revised to about 32 miles. "Water Board Approves the Power Sale," The Arizona Republican, 2 August 40 E. M. Hewlett, "A New Type ofInsulator for High Tension Transmission Lines," Proceedings ofthe American Institute ofElectrical Engineers (26 June For a discussion of the development of insulators prior to this time see Swanson, 41 For more information see E. M. Hewlett, "A New Type of Insulator for High Tension Transmission Line;" H. W. Buck, "Some Methods in High-Tension Line Construction;" D. R. Scholes, "Fundamentals Considerations Governing the Design of Transmission-!ine Structures," Proceedings ofthe American Institute of Electrical Engineers (26 June Downing, THEODORE ROOSEVELT DAM.

EASTERc"J MINING AREA TRcA,NSMISSION LINE HAER No. AZ-6-C (Page 15) Suspension insulators solved a variety of problems in transmission line construction. They carried the wire beneath the crossarm so large birds were less likely to touch it and short circuit a wire. Together with overhead ground wires and aluminum cell arresters, they reduced the threat of lightning. Finally, because they were able to carry higher voltages, these insulators allowed electricity to be carried over greater distances. Longer spans were of minimal concern in a climate where heavy snow and sleet conditions were rare. On double circuit towers, the most distance between towers was 800 to feet, approximately twice the span of the original tower 10cations.

Lines could therefore have fewer towers, making ~onstruction more economical. 42 In October linemen tested towers for the reconstruction of the Roosevelt-Mesa 43 transmission line. Engineers drew specifications according to the most recent innovations. Project engineers determined that they could rebuild the line according to recent industry advances by reconstructing the tower tops to carry suspension insulators and support ground wires, and by removing every other tower since the new design would allow for larger spans between the taller towers. The materials and towers taken from the old line would be salvaged and used to build the new Inspiration line. The money the Inspiration Copper Company provided for the new line would fund both projects.

This solution not only offset costs, but at the same time, ensured a uniform and contemporary transmission system. This notion of saving 44 money through the process ofline reconstruction was ten years ahead of common practice. Chief Reclamation Service Engineer Irving C. Harris directed reconstruction efforts from A crew surveyed the line from August through September of while Ensign oversaw the sample tower testing. A detailed report in November described the construction process. Workers began to set foundations for the new line in January and relocation for the old 45 began in April. Tower materials arrived in the summer. Workers removed 260 towers from the Roosevelt-Mesa line. They left many foundations in place.

They replaced the crossarms with three new angle iron crossarms on top of each of the remaining towers. These new extensions 42 D ownIng, . . _ - 43 Files, Salt River Project Archives: Department of the Interior, Reclamation Service, Twelfth Annual Report ofthe Reclamation Service, (Washington D. c.: Government Printing Office, 52. 44 P. O. Reyneau and H. P. Seelye, "Transmission-Line Reconstruction," Electrical World 75, (3 January 3 7. 45 The bases of the towers remain the same as the originals. Each tower foot was anchored to concrete footing. By engineers had determined that this was still a much more reliable method of securing steel towers against vertical and horizontal loads.

All steel footings, although cheaper, required a perfectly flat surface on which to rest or there would be unequal stresses on different legs of the anchor. J. B. Leeper, "Foundations for Transmission Line Towers and Tower Erection: II- Transmission Tower Steel Anchors Set in Earth," Transactions ofthe Annual Convention ofthe American Institute ofElectrical Engineers (20 June THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page 16) carried conductor wire by suspension insulators (see AZ-6-C-15, When towers were taller, the span, or space between them, could be increased and the number of towers reduced.

46 The length of the extensions varied from three to fifteen feet above the original towers' height in order to accommodate any increased line sag caused by the increased distance between towers. In the mountains, workers removed 40% of the towers. Most of these were taller towers. They placed the shortest possible extension on those remaining. Engineers strung telephone wire six 47 feet below the power wires for inter-Project communication. The government sold the bulk of the removed tower material to Inspiration and subsequently used it to build the line from Roosevelt to Miami. They were essentially the same towers, but with shorter extensions, and double braced because a more level terrain allowed longer spans.

The salvaged material not used on the Miami line was saved for use at a later date. These parts included porcelain pin-type insulators, tie-clamps used to tie wire, 142 cast iron anchors for scrap cast iron or guy anchors, and 272 pounds of twelve foot galvanized channel . 48 Iron. Work was completed in January and Inspiration's substation received power on March 49 21. The reconstruction went relatively smoothly, except at least three inexperienced workers died from falls or electrocution. 50 A severe September storm blew down two miles of the new line. Wood poles were used as temporary replacements. Engineers insisted that the tower failures were not due to a fault in design, but to highly unusual and unanticipated violence in the weather.

51 The following year, s Annual History reported that the new line design had, for the most part, remedied the hawk and lightning problems of the past. The stretch from Mesa to Phoenix, which still carried pin insulators, continued to experience interruptions. 46 D. R. Scholes, "Transmission Line Towers and Economical Spans," Transactions ofthe American Institute ofElectrical Engineers (26 June 47 Telephone lines were used for inter-Project communication only. SRP never ran a public telephone service. "Construction of a Transmission Line in Arizona," 48 Foundations of removed towers can still be seen along the right of way. Gaylord, Power and Pumping, File labeled "Miami-Roosevelt Salt River Project Archives.

This file contains detailed instructions regarding reconstruction, work order for parts, hand-written instructions, and maps of the line locations. 49 SRP Annual History, 50 Investigators of these accidents determined that the workers' inexperience and their misunderstanding of instructions caused these accidents. Phoenix Gazette, 23 December Arizona Record, 15 January ) 1 File labeled "Miami-Roosevelt Salt River Project Archives. THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page 17) In and six towers near Fish Creek failed because of a lightning and wind storm. By due to a number of tower downings, most towers were side guyed with three-fifths galvanized strands and attached to seven inch channels or rock anchors.

According to accepted standards, a guy anchor was placed about one- third the distance of the tower's height from its foot. 52 Power workers periodically replaced faulty and broken insulators up and down the line. 53 However, after ten years, the SRP Power Division only needed to replace 250 out of . 1ators. 54 msu In November engineers had estimated a cost of to reconstruct the line. The number included materials for towers pounds), insulators and fittings, ground wire, telephone wire, tower fittings, and labor charges. The Reclamation Service contributed for materials, yet by the project's completion the price reached almost Nevertheless, other mines in the area followed Inspiration's lead. VI.

Striking it Rich with the Mines Between and the Magma Copper Company in Superior built a concentrator with a capacity of 200 tons per day. Under arrangements with Inspiration, Magma constructed a substation and a mile single circuit steel tower line over rough terrain from Miami to Superior in order to receive some ofInspiration's power to operate its concentrator and smelter. Constructed from spare parts, towers were essentially identical to those on the Roosevelt-Mesa and Roosevelt -Miami lines. Spans as large as feet between towers were common. Magma financed the construction in order to receive a portion of the power coming to Inspiration from the Roosevelt Dam powerhouse.

Although it connected to the government system, Magma owned the line (see On June 12, the United States signed its first contract with Magma. The company agreed to construct a power plant, transmission, and telephone lines from Roosevelt Dam to Magma's new substation at Superior via Goldfield. A 50% credit on 52 Connery, F. C. "Foundations for Transmission Line Towers: V. Toronto Power Company," Proceedings ofthe American Institute ofElectrical Engineers,( July . 53 SRP Annual History, 54 Twice, conductor lines broke at a point near the insulator. The copper may have been weakened by the continuous bending due to swinging lines.

SRP Annual History, 55 "Will Revise Power Line," Arizona Republican,S November Norman Rowe, "Lightning Rods and Grounded Cables as a Means of Protecting Transmission Lines Against Lightning;" A. Bang, "Four Years' Operating Experience on a High-Tension transmission Lines," Transactions ofthe American Institute ofElectrical Engineers, (26 June 191 Gaylord, File marked "Miami-Roosevelt Line, Salt River Project Archives. 56 Gaylord. THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page 18) Magma's monthly power bills reduced the estimated construction cost of by Upon completion, the structures would become the property of the United States.

57 The following ApriL the Association built a single circuit line from Goldfield to Superior along with the hydroelectric power plant at Chandler. Like the line from Mesa to Miami, Goldfield- Superior was at 25 cycles, but because of cost, it was carried by wood poles (see - This stretch of the transmission system was the most vulnerable line to lightning strikes, and the section between Queen Creek and Superior experienced an excessive number of outages. In the Magma Railroad Company had to relocate some of the poles that were running through its right of way. 58 VII. Completing the Circuit: "The Loop" During World War I, industries came to the Salt River Valley in Arizona to produce Egyptian long staple cotton used for the production of tires and airplane fabric.

As the war came to an end, however, the demand for cotton and other products dropped. This imposed a significant financial hardship on Salt River Valley farmers. In November the government had turned over the Project to the Salt River Valley Water Users' Association. The Association still needed to pay off its ten million dollar debt for the construction of Roosevelt Dam. By the early economic conditions forced it to defer its repayments. In addition, the potential load demand on the power system increased as electric service became available to farmers and the mines expanded with the growing copper industry.59 The Salt River Valley Water Users' Association instructed newly elected Chief Engineer Charles C. Cragin, together with civil engineer F. J. O'Hara and electrical engineer H. J.

Lawson, to investigate economical ways to secure additional 60 power development and power sales, particularly to the copper mines. Cragin's report, completed in concluded that regulating the Verde River could generate over 50,OOOkV of additional hydroelectric power. The report recommended increasing the )7 Another agreement on October 12, modified the contract. The government completed part of the construction at a cost of which Magma was to pay back. Sheridan, xvi; Glenn W. Brandow, "Historical Documents Pertaining to Power Contracts and Agreements of the Salt River Project," (Phoenix: Salt River Project. 58 File labeled "25 Cycle Conversion," Salt River Project Archives; SRP Annual History 59 The Magma Copper Company was organized in to work the Silver Queen Mine.

Eventually, it mined primarily copper. From they renewed activity on the Silver King Mine as well. Tuck, "History of Mining in Arizona." 60 Charles Cragin, a graduate of New York University had worked as a consulting water supply in numerous cities across the country. lntrocaso. THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page 19) storage capacity of Roosevelt's reservoir, remodeling the existing power plant to correct sources of intemlption, and constructing the Mormon Flat Dam for additional hydroelectric power. Cragin also suggested building another dam, between Mormon Flat and Roosevelt. Horse 61 Mesa's construction would be the focus of the Salt River Project's expansion.

Finally, in order to deliver the additional power generated at the new Mormon Flat power plants, the Project would need to convert the transmission system to a llOkV single circuit connecting Goldfield, Roosevelt Dam, Mormon Flat, Miami-Inspiration, and Superior through new substations at Goldfield and Superior (see figure The Cragin report proposed that the present line could be modified to a 11 OkV loop through economical reconstruction; they worked from what they had and recycled parts from old projects. The old windmill towers in the area, made of galvanized steel and anchored on concrete foundations, still satisfied industry standards. By the steel towers were the most accepted type of transmission structure tor high voltage lines. E. F.

Gemmill wrote a series of articles for the Electrical Review explaining the latest practices in designing steel tower lines. Unlike steel poles, or flexible steel frames, rigid towers could withstand loads at angles and from a number of directions. The loop would operate as a closed system. The amount of electrical power delivered, knOWfl as "loading," would be equally divided on both sides.

With two lines entering the circuit from separate routes at every point of use, Cragin's report boasted that "with the changes contemplated for the new development, it will be one of the most reliable transmission systems in existence." 63 Like the alterations, the tops of the steel windmill towers would again be reconstructed to convert the line to a single circuit This would eliminate half of the wind pressure on the wires and reduce their dead load by about 800 pounds per tower. Parts would again be salvaged and 61 In the Board of Governors also approved the Stewart Mountain Dam Project. Frank Martos and Jerry D.

Smith, "History of s Electric System: A Phase I Study Report Long Range Electric System Plan, Power System Analysis, Salt River Project," (Phoenix: Salt River Project, July Copy located in the Salt River Project Archives; Also see Introcaso. 62 A voltage of IIOkV was selected because structures and conductors could be adapted and the voltage was an appropriate level at which to handle the amount of power. The Goldfield substation would provide duplicate autotransformers to regulate voltage to the Valley and to the dam sites, while at Superior and Miami, the substations would reduce the voltage to so that the transformers already at Magma and Inspiration could handle the load.

For a more detailed description of the entire transmission system, see Cragin, "Report on Proposed Additional Hydroelectric Power Development of the Salt River," (Phoenix: Salt River Valley Water Users' Association, February 63 E. L GemmilL "Steel Transmission Line Structures," Electrical Review 76, (March-May Cragin, THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page 20) reused. Cragin also presumed that the wood pole line from Goldfield to Superior could be adapted to the higher voltage by resetting the poles and by using the salvaged copper from the two circuit Roosevelt-Miami line. The only new construction the engineers predicted was 4.6 miles of line connecting the new Mormon Flat Power Plant to the existing line.

Conductors would be B& S Gauge Stranded" copper cable throughout the entire loop, except between the Roosevelt Power Plant and Dam where one of the existing "#1 S & S Gauge" copper lines was removed. Meanwhile, workers relocated towers from the Mormon Flat reservoir site and built miles of 11 OkV line to the Mormon Flat Power plant. Construction for the 4.5 mile long transmission line into Horse Mesa, over particularly terrain, was completed between '4 October and May AZ-6-C-21, (J With expansion, the Association renegotiated its power contracts with its biggest customers. On January 3, Magma Company near Superior transferred its line to the Inspiration substation. Magma could use up to of power offthe line for 50 years without cost.

On June 14, Inspiration, then one of the largest industries in Arizona, signed a contract with the Association to purchase all the hydroelectricity generated from the new dam, Horse Mesa, in order to power its new six million dollar leaching plant. This agreement essentially funded the dam's construction. It also required the Association to build two new transmission lines to carry that power to the copper company's Miami operations. Along with paying the cost of construction and operations, the revenue would further aid the farmers in the Salt River Valley in repaying the government for the Roosevelt Dam project, as well as provide funds for electrifying the Valley.65 The Association also secured ownership of the Magma's line from Miami to Superior.

From April through at least November workers built brand new steel towers from Goldfield to Superior along the old wood pole line which they removed and salvaged. The 66 Muskogee Iron Works Company of Muskogee, Oklahoma provided the new towers. Unlike the square windmill-type towers that made up much of the loop, these were rectangular transmission 64 There is almost no information available as to the manufacturer of these towers to Horse Mesa, and perhaps Stewart Mountain Dam. However, they are almost identical to several types seen and advertised in engineering journals during this time period, Their particular pyramidal design was appropriately chosen for the particularly steep and rocky terrain near Horse Mesa Dam.

SRP Annual History, See also Bang, "Four Years' Operating Experience on a High -Tension Transmission Line," Proceedings ofthe American Institute of Electrical Engineers (26 June 65 The agreement was supplemented and modified in November A copy of this agreement was reproduced in the July 15, issue of The Associated Arizona Producer. The entire II OkV loop cost just over Introcaso, "Agreement Between the Salt River Valley Water Users' Association and the Inspiration Consolidated Copper Company," (14 June Copy available at the Secretary's Office. Salt River Project. 66 These towers are also on the transmission line to Mormon Flat. SRP Annual History THEODORE ROOSEVELT DAM, EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page 21) towers.

Tower designs had become increasingly sophisticated since the windmill model. Although engineers decided the best arrangement of wires, calculated loadings under various local climactic and topographic conditions, and assessed the dimensions and strength required of the structures, the manufacturers with the best bid often determined the actual design of 67 transmission towers. Muskogee employed slight alterations depending on the function of the tower. Intermediate towers were the most common. They placed an extra arm on angle towers. Transposition towers, which come in pairs, had additional elevations in order to transpose the wires in order to decrease the electromagnetic field.

Each ne~ tower took workmen about eight hours to erect AZ-6-C-24, 67- 68 The Association purchased additional parts from the United States Steel Products Company in San Francisco, California for the existing steel tower lines from Goldfield to Miami via Roosevelt. These consisted of cross arms, diagonals, plates, galvanized poles, and washers. On each tower, workmen removed or off the middle cross arm and placed three sets of insulators on the remaining ones (seefigure #3, AZ-6-C-18, 19, 61, All the older towers 69 required new tops and crossarms to gain higher clearance for the higher voltage. They replaced all the conductors with the larger copper conductor wire. Workers relocated 27 and added 23 towers on the Superior-Miami line.

They also moved two and a half miles of the Roosevelt- Miami line to release storage space for the new leaching plant at Inspiration. Finally, they relocated five towers near Roosevelt to allow the Apache Trail to reach the Horse Mesa reservoir site. few years later in for unknown reasons, engineers found it necessary to install 29 miles of overhead ground wires from Goldfield to Superior. They also added ground wires and changed out steel crossarms with wood ones from Superior to Roosevelt via Miami, and from Roosevelt to Mormon Flat (see AZ-6-C-63, 70 Engineers may have made the latter decision because unlike steel, engineers could calculate the precise strength of wood regarding its ability to hold heavier conductor wires.

The began operating on August with the Mesa Switching Station and Superior Substation (see AZ-6-C-19, 71 67 For more detailed description about the factors determining steel transmission tower design, see GemmilL 68 SRP Annual History "A Story Without Words," (photo series) The .4ssociated Arizona Producer 4 (l November 5. 69 Engineers used some of the old line Locke insulators, but replaced others with the new ones from Westinghouse, insulator no. 60 L 70 Other subsequent changes are noted on referenced drawings 63. 71 SRP Annual History i File marked "Miami-Roosevelt i Salt River Project Archives. THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRANSMISS[ON LINE HAER No. AZ-6-C (Page 22) In workers began constructing Horse Mesa Dam.

That same year, the Association signed a contract to sell power with the new Nevada Consolidated Copper Company at Ray. The agreement added dollars a year to the Association's income. It allowed for the sale of power from Horse Mesa that was produced in excess of the amount contracted to Inspiration. Also like the Inspiration agreement, Nevada's contract stipulated that the transmission line, valued at would become the Association's property after twenty-five years. As well, the Association supervised construction at the company's expense, and was allowed to purchase power from the mine's auxiliary equipment in times of water s.hortage. 72 From March through June of the Project constructed a new 13 mile, steel line from Superior to Ray off Il0kV loop.

The 87 towers were rectangular, similar to those from Goldfield to Superior, the Pacific Steel Company in San Francisco supplied a slightly different design (see AZ-6-C-27. The Linemen The men who built the 11 OkV loop worked out of four camps located at Horse Mesa, Miami, Superior, and Roosevelt. Like the linemen who had worked on the first reconstruction, these workers were primarily young single men, some local, or often drifters or miners, who sought temporary jobs. Often they had little, ifno experience in linework. They earned about three dollars a day, approximately 50 cents less than the mines paid. However, strikes often plagued the mines so laborers could not always rely on steady work. The Project provided tents for linemen to live in, but they slept in their OVvTI bedrolls.

Cooks provided their meals for one dollar a day. Jess Stoker, a long time Salt River Project employee, began as a lineman in building the steel Muskogee towers from Goldfield to Superior. He lived at the "Top of the World" camp, located halfway between Superior and Miami, with about fifty other men. Bob Ward was the line toreman, but Charles Keats, who worked at the Miami-Pinto Creek camp, supervised the loop's construction. Jess Fulton was in charge of wiring, and Ira Levin supervised the telephone line.

Additional crews removed the telephone line trom the towers and, according to Stoker, strung it 72 The mines produced tons of ore daily, meaning tons of refined copper valued at Nevada Consolidated Copper Company took over the Ray Consolidated Copper Company in Inspiration also received power for its mills, concentrators and smelters from a power house that utilized reverberatory waste heat and also produced power from oil-fired boilers. Drawing Salt River Project; "Salt River Valley Farmers to Realize Yearly Income From Power Furnished Ray Mines," The Associated Arizona Producer 5 (i 5 December Martos and Smith; For detailed information about their equipment see G. R. Rubley, "The Story of the Miami-Inspiration Copper District," Arizona Historical Foundation, Arizona State University.

THEODORE ROOSEVELT DAM, EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page 23) on 18 foot boiler tubes with crossarrns 100 feet away from the power line. The boiler tubes were probably salvaged parts from a substation and re-used for the telephone lines. 73 Stoker described an atmosphere where "everybody was working to enjoy themselves and get the job done.,,74 They drove to work in old trucks which could only reach miles an hour on the rocky dirt roads. Although they often graded the road, it was at times even too rough for mules. Sometimes it was just easier to walk to a tower's designated location. Once at the erection site, explained Stoker, We started from the bottom right up and built them piece by piece. We didn't have any equipment or nothing, only just a handline.

That's a pulley, a hook, on the end of a rope hanging up on the end of the steel and start the construction ... We had everything in those days that was available that we needed. We could have used other stuff but we didn't have it and didn't know anything 75 about it. We had one winch truck, that is, with a pulley on it so you could pull the wire in. - Except for an occasional mashed finger, there were few, if any, reported accidents. Once the Ray line was completed, the system reconstruction was for the most part finished, and most of the linemen were laid off. 76 IX. Epilogue Since the alterations, the Salt River Project has made few alterations to the transmission line in the Eastern Mining Area. Most modifications consisted of maintenance, part replacement, or tower relocation.

Some towers were removed. One of the most significant developments resulted from yet another voltage increase, but more significantly, a frequency change as well. In the Project introduced a new 60 cycle frequency system to the Valley. Although electrical lines and appliances operating at 60 cycles were becoming the national standard, the Salt River Valley still operated at the 25 cycles required by the mines, the largest power customers. After World War II, however, the Salt River Valley's urban areas and population significantly grew. The electrical service at 25 cycles and volts was far below contemporary industry practice, especially for modem urban areas. By the manufacturers 7j A Mr.

Munster was foreman at Horse Mesa camp, and Azell Henshaw, one of three linemen brothers, directed the stretch from Roosevelt to Pinto Creek. Jess Stoker. Interview by Harriet Haskell. (Transcript: SRP Historical Research and Archives Project, 10 April 74 Stoker, 3. 75 Stoker, 7. '6 . Stoker. 6, lO. THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page were no longer making 25 cycle equipment and appliances. In addition, the low frequency caused household lights to flicker. Finally, the old system could no longer sustain the loads required by Phoenix's industrial development. SRP recruited experienced personnel from California and began plans to convert the entire transmission system. 77 Frequency conversion required four main stages.

First, the electrical equipment itself, the generating plants, substations, and transmission system, would need to be changed. Next, the Project would have to replace the equipment for the mines, commercial establishments and residential areas, Unlike the 50 to 60 cycle change in California, the increase from 25 to 60 cycles required the replacement of operating equipment. The mines, however, who were the largest power customers, still preferred 25 cycle which most of the industry considered ideal for industrial use. SRP purchased frequency changers and placed them at Mesa in order to isolate eveI"jthing east of the Mesa Switching Station, which was essentially the 11 OkV mining loop, to 25 cycles. 78 For years, the Project sought to persuade the mining area to upgrade.

They were finally successful in In order to bring 60 cycles to the mining tOy\TIS, the Project built a new 60 cycle line from Goldfield to Superior, parallel to the old one. This way the mines could use either or both frequencies depending on the age and capabilities of their equipment. Perhaps aside from changing out the conductor wires, the old transmission lines or towers needed no major alterations for the frequency change. In SRP contracted with the Kennecott Copper Company at Ray, increasing services to Ray and Superior from to at 60 cycle. The Project converted the lines from Mesa to Goldfield, Goldfield to Superior, and Superior to Ray. The Superior-Miami line followed in when Inspiration's contract required the company rebuild a mill with 60 cycle equipment.

79 By the mid-1960s, SRP management was eager to upgrade the frequency in the mining area. They considered the 25 cycle loads inefficient and obsolete and urged new contracts with the 77 About Salt River Project administrators Searles, Best, and Floyd Smith recruited people from California to direct the Project's frequency conversion. The four main managers from California included Rod McMullin, Henry Shipley, Stan Ward, and Thomas Morang. Morong's former Supervisor at the Southern California Edison Company, C. L. Sidway also worked for Westinghouse in Arizona. He often toured the mining areas and advised the copper companies on electrical equipment.

When the Los Angeles consulting firm of Leeds, Hill, Barnett, and Jewett was asked to prepare an economic survey of the Salt River Project, Sidway was enlisted for the electrical section. The resulting report strongly suggested the need for a Project wide frequency conversion. Having frequently consulted with Sidway about the Arizona situation, Tom Morong became chief engineer for the Salt River Project. Tom Morong, Interview with Harriet Haskell (Salt River Project Historical Research and Archives Project, 78 "Mesa Switching Station," The Current News, 79 In the Project built a 60 cycle line from Ray to Hayden, and in they built similar lines from Hayden to Coolidge and from Goldfield to Stewart Mountain. THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRANSMISSION LINE HAER No.

AZ-6-C (Page mining companies to force out the 25 cycle system. Their hopes turned urgent when the hydro plant equipment needed rebuilding in order to adequately supply the mining load when water conditions restricted hydrogeneration. Inspiration held out longer than the other mining industries, and its general manger, Bud Neal, agreed to use a frequency changer at the mine so that the rest of the loop could be converted.

Finally, by the last phase of the Hydro Expansion and Frequency Unification project (HEFU) completed the frequency conversion for the entire Salt River Project electrical system.so Project maintenance did not check the II OkV loop tower by tower until At that time, engineers Max Seaton and Clem Allen and estimator George Shanks found weakened crossarms, metal corrosion, damage to foundations, and defective down guys and anchor rods. However, most of the forty year old towers could continue to effectively transmit electricity to the mines. The engineers recommended adding a special armor rod to prevent damage to clamps that were pinching the conductor wires, as well as some replacements of guy wires and crossarms.

They also suggested replacing the galvanized steel guys and anchor rods with copper clad steeL Maintenance workers have replaced insulators on many towers, but some still operate with the originals. The Project has also added to the line, or replaced a number of the older towers, with wooden "H-frames."S! The original steel towers from Goldfield to Superior and from Superior to Ray remain essentially untouched since their construction in the long-range study conducted in predicted that mining loads in the eastern mining area would probably "never reach historical peak levels."s2 However, future plans focused on the individual needs of particular areas and companies.

In the Project built its first EHV (Extra High Voltage) transmission lines; a current traveling from Cholla to Silver King s3 and connected Silver King to Goldfield and Kyrene. 80 Fred Henshaw, Interview by Harriet Haskell, (Transcript: SRP Historical Research and Archives Project, 3 February March Morang, 22; Martos and Smith, T M. Morong, Manager, Power Operations to G. W. Brandow, Assistant General Manager, Power Operations, 8 December Salt River Project Archives. 81 Henry F. Unger, "Close-up of a Check Up," The Current News ( September Salt River Project Archives. 32 Memo, William G. Breyer to Executive Planning Committee. (7 December Salt River Project Archives. 33 "Eastern Mining Area Transmission System: Summary Report," (July Salt River Project Archives.

THEODORE ROOSEVELT DAM, EASTERN MINING AREA TRANSMISSION LINE HAER No, AZ-6-C (Page 26) X.

Conclusion The early EMA transmission line delivered the energy needed to produce two of Arizona's most valuable economic resources, cotton and coppeL Arizona provided these essential raw materials for industrial America throughout the early 20 th century, Revenue from the sale of power to the mines, the Project's largest customers, funded the building of power dams that in tum brought electrical power to the Salt River Valley, The transmission system enabled a large-scale government water storage project to become a complex hydroelectric system serving most of central Arizona, Thus, the long distance transmission of hydroelectric power to farms and mines transformed the region into an area of great wealth and prosperity.

Finally, although the Salt River Project has modified and, in some cases, relocated the original towers, it completed most changes early. Today, the lI5kV towers illustrate the rapid development in long distance, high voltage electrical transmission technology and tower design in response to society's needs. THEODORE ROOSEVELT DAM. EASTER:"l MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page ... I ~.. :"" 1Z;-'.i..:.S . ,-_ ",- Figure 1 EXISTING MINING TRANSMISSION SYSTEM provided by the Salt River Project, Phoenix. Arizona THEODORE ROOSEVELT DAM. EASTERN MINING AREA TR,,\NSMISSION LINE HAER No. AZ-6-C (Page 28) / / / / " '("'l~!.\...-6~"":It!~~ ...

"" " L.,EGe-NO ~~_ ~''''rIt~ ;;"""C\?o-...cll :::o.,.,..u" I I / I EXI.5TiNG ANQ PROPOSED POWER DEVELOPMENT Or' .5ALTRlVER ';Al7' 'IAl.J.LY WAT""Jl U::l:RSA=CJAnON i='"1--;QE"":-'Il'X. ,.:...Q!.ZCl'-<A. Figure 2 From Cragin, "Report on Proposed Additional Hydroeiectric Power Development of the Sail River, ,. Salt River Valley Water Users' Association: Phoenix. February THEODORE ROOSEVELT DAM, EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page 29) \IAY.1923 PORCEL\lN SUSPE::'lS10N.IYPE INSL;UTORS-Cont':nued Two of Insulator No. 601 Insulator No. of one unit 601 Trade voltage rating per unit Dry o\"e: :oitage. LeJ.ka~e ~is~ance, et distanc~. :nche~ ",' . ~ Diame:ec "i insulater. ;"ches ,,) Distancz :,e~:.. ~~ -:~:1:.e; 0:' ~ .~P9rox:~at.z :"let ';\ e;~h: ;>e:- iOO ::; ;;'0t.:::~:i_.

Appro~:~r.la':.c .\ e:~h~ ~ac~~~~ ;Je~ iOO ::: P::lCh~ed 3. -i. 5. 'Jr t} :>e: "::-.:i"~ :esi:-:: :. ~e':" ~oo :I~jc 00 figure .) From 'Westinghouse: Catalogue of Electricai Sucplies ! ?:ttsbur~il: \Vestinghouse Electric and 'vlanufacturing Compan:_ Cup; in 'he Sa it R:ver ProJec;: Research Archives_ THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page 30) Bibliography Manuscript and Archival Collections Arizona, Tempe, Arizona Historical Foundation, Arizona State University. ___ ' Research Archives, Salt River Project. ___ . System Design and Construction, Salt River Project. Texas, Canyon. Windmill Mfuiufacturer's Trade Literature Collection, Historical Research Center, Panhandle Plains Historical Museum. Government U.S. Department of the Interior.

Reclamation Service. Annual reports of the U. S. Reclamation Service, - - -. Annual History of the Salt River Project, Introcaso, David M. "Mormon Flat Dam," Historic American Engineering Record (HAER), No. AZ-14, Jackson, Donald C. "Theodore Roosevelt Dam," National Park Service, Historic American Engineering Record (HAER), No. AZ-6, Pfaff, Christine. "Theodore Roosevelt Dam, Power Plant," National Park Service, Historic American Engineering Record (HAER), No. AZ-6-A, Swanson, Mark T. "Santa Ana River Hydroelectric System," National Park Service, Historic American Engineering Record (HAER), No. CA-130, THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page 31) Reports and Papers Cragin, Francis 1. O'Hara, and Henry 1. Lawson.

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"Tower Foundations for Transmission Line Towers and Tower Erection: The Alabama Power Company." Transactions ofthe Annual Convention ofthe American Institute of Electrical Engineers (20 June Quivik, Frederic L. "Historical Landscapes: Early Steel Transmission Towers and Energy for Montana's Copper Industry." iVJontana: the iVJagazine of Western History 38 (Fall Reyneau, P. O. and H. P. Seelye, "Transmission-Line Reconstruction," Electrical World 75, (3 January THEODORE ROOSEVELT DAM. EASTERN MINING AREA TRANSMISSION LINE HAER No. AZ-6-C (Page 33) Rowe, Norman. "Lightning-Rods and Grounded Cables as a Means of Protecting Transmission Lines Against Lightning." Proceedings ofthe American Institute ofElectrical Engineers (6 June Scholes, D. R.

"Fundamentals Considerations Governing the Design of Transmission-Line Structures." Proceedings ofthe American Institute ofElectrical Engineers (29 June _ _ _. "Transmission Line Towers and Economical Spans.'~ Transactions ofthe American Institute ofElectrical Engineers (26 June Walls, J. A. "Foundations for Transmission Line Towers and Tower Erection." Transactions of the Annual Convention ofthe American Institute ofElectrical Engineers (20 June wnitehead, John S. "Hydropower in Juneau: Technology as a Guide to the Development of an Alaskan Community." Pacific Northwest Quarterly 75 Baker, T. Lindsay. A Field Guide to Windmills (Norman: The University of Oklahoma Press, Hoy, Suellen M., Michael C. Robinson, and Ellis L. Armstrong.

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