Power For Bodie

[Subdeacon Joe]

Throwback Thursday
Thank you to author Michael H. Piatt for this contribution.

When Bodie’s Standard Company sought to reduce operating expenses, Superintendent Thomas Leggett chose to replace the mill’s wood-fired boiler and steam engine with an electric motor. A small hydroelectric plant would furnish electricity to run the mill at almost no cost, but the major problem facing engineers was the distance from the nearest source of reliable water power. Between 1892 and 1893, Westinghouse Electric & Manufacturing Co. designed and built a transmission line to the Standard Mill that stretched 12.46 miles cross country in nearly a straight line from Green Creek in the Sierra foothills.

Author Ella Cain’s popular folktale about electricity jumping off wires on curves is not supported by Leggett’s technical report that describes Bodie’s success in transmitting electrical power over a long distance. It also does not account for vertical curves (hills and valleys). “The line crosses extremely rough country,” wrote Leggett in his paper to the American Institute of Mining Engineers, “not 500 yards of which is level beyond the town-limits. Most of the ground is very rocky, over 500 pounds of dynamite being used in blasting the pole-holes.” (1)

Curved wires were not listed among the venture’s many obstacles, and electrical engineering journals of the era did not mention the problem. (2) Instead, surveyors plotted the transmission line as straight as possible for two reasons:  minimize the pole line’s length and reduce its cost. Both reasons were based on the principle that the shortest distance between two points is a straight line.

Since the mid-1880s, when urban centers began adopting electricity for lighting and trolley cars, engineers had struggled to transmit useful voltages farther than three miles. Meeting the Standard Mill’s energy requirements from a power source more than 12 miles away would be fraught with difficulties, if not impossible. To increase the odds of success, a straight transmission line afforded the shortest distance between mill and power plant.

Given that the Standard Mine had been yielding ore of ever-diminishing value during the previous decade, Leggett’s expendable capital was limited. So, he strove to control expenses. Since zig-zagging wires would require more materials, he called for a transmission line that extended directly between Green Creek and Bodie.

Two photographs from the Twelfth Report of the State Mineralogist (1894) prove that the transmission line had plenty of curves. Most curves, however, were up and down. Crossing over a mountain range is almost always shorter than traveling all the way around. The same is true for canyons. Perfectly straight wires would have required tunneling through hills and bridging valleys. Photos show the transmission line, one looking east, the other west, taken about 10 miles from Bodie.

Michael H. Piatt’s website is bodiehistory.com. His book, “The Mines are Looking Well,” can be purchased here: bodiefoundation.org/store
#ThrowbackThursday

 1.Thomas Haight Leggett, “A Twelve-Mile Transmission of Power by Electricity,” Transactions of the American Institute of Mining Engineers, 24, New York, NY:  A. I. M. E., 1895:  315-338.
 2.Thomas Haight Leggett, “Electric Power Transmission Plants and the Use of Electricity in Mining Operations,” Twelfth Report of the State Mineralogist, Two Years Ending September 15, 1894. Sacramento, CA:  Superintendent of State Printing, 1894:  413-435; Electrical Engineer (New York, NY) 7 January 1891—28 June 1893; Electrical World (New York, NY) 3 January 1891—30 December 1893.