Powering Up
The GE and Westinghouse High Voltage Laboratories, from local to transnational grids.
No Danger, High Voltage Simulating Lightning GE’s Lightning Circus Challenging Environments
No Danger, High Voltage
From the 1910s, progress in electrifying major U.S. cities like New York, Philadelphia and Chicago was driven by the interconnection of independent electrical generating plants. Success depended upon increasing capacity and achieving cost efficiencies by raising transmission voltages up to 220kV. These voltages demanded larger, more robust towers, circuit breakers, transformers, and other equipment, which needed electrical insulation capable of withstanding short-circuit surges and lightning strikes.
Manufacturers of electrical power equipment like GE and Westinghouse responded by created dedicated space at their industrial plants for high-voltage research and testing laboratories. The pioneering research and rigorous testing carried out at these sites made possible safe long-distance, high voltage transmission of electrical power.
GE High Voltage Lab, Pittsfield, Massachusetts
GE operated an electrical manufacturing plant in Pittsfield from the early twentieth century. By 1908 nearly all GE transformers were manufactured there, along with flat irons, electric fans, and small motors. The high voltage laboratory dates to 1914 as a distinct location within the plant, at the end of a new transformer assembly and testing building.
One-million volt, three-phase arc, 1922
The demonstration became a staple of “open house” events for GE employees and their families. Three testing transformers each stepped up 2.5kV to 578kV, giving 1000kV phase-to-phase.
Museum of Science and Innovation
Impulse generator, 1923
Its enormous capacitor banks produced two-million-volt discharges that simulated the effects of lightning surges.
G.E. Current News, July 1923, in Transformers at Pittsfield (part II)
Cascade test transformers, 1925
The individual voltages of each transformer were combined by connecting their high voltage windings in series. This avoided the costly insulation requirements of a single high voltage AC test transformer.
G.E. Current News, November 1925, in Transformers at Pittsfield (part II)
Westinghouse High Voltage Lab, Trafford, Pennsylvania
50 feet tall from floor to ceiling, the laboratory formed part of the Westinghouse power circuit breaker division at the company’s plant in Trafford, Pennsylvania. Construction began in the fall of 1920 and was completed in 1921. The steel beam and corrugated sheet metal structure measured 110 feet by 120 feet. Locals called it the “Tin Shed.”
Interior of Westinghouse High Voltage Lab, 1922
View of the crane, testing transformers and testing pits.
Trafford Historical Society Westinghouse Collection
One million volt testing transformer
Plant records described the one million volt transformer as “the first commercial unit ever built for that voltage above ground in a single unit.”
Trafford Historical Society Westinghouse Collection
Burned out transformer windings
In 1925 the one million volt transformer fell victim to hubris when its windings burned out.
Trafford Historical Society Westinghouse Collection
Replacement testing transformer
An 800kV replacement transformer is lowered into the tank during fall 1925.
Trafford Historical Society Westinghouse Collection
Sphere gap apparatus
The spark distance between the charged spheres could be used to determine voltage.
Trafford Historical Society Westinghouse Collection
Office and control booth
Viewed from the crane on the laboratory floor.
Trafford Historical Society Westinghouse Collection
Electrical engineers in 1920s high voltage laboratories tested and improved insulating materials that enabled transmission lines to be hung from towers and routed into transformers. They investigated how weather, such as rain, fog or snow, reduced an insulator’s dielectric strength, or its ability to withstand electricity; the behavior of lines under storm conditions; and phenomena such as corona and power loss.
Electrical engineers and scientists in the 1920s analyzed, categorized, and quantified their experience and experiments to establish a science of insulation.
Thomas Hughes, Networks of Power
Wet flashover at 650kV, 7-unit post
Trafford Historical Society Westinghouse Collection
Corona at 850kV, 9-unit post
Trafford Historical Society Westinghouse Collection
Fifty-foot arc from the one million volt transformer
Trafford Historical Society Westinghouse Collection
Condenser bushing flashover at 120kV after internal puncture
Trafford Historical Society Westinghouse Collection
Simulating Lightning
By the 1930s urban dwellers expected electricity in their households. President Franklin D. Roosevelt promoted rural electrification under the New Deal. City grids began to evolve into regional electrical power networks. In the high voltage laboratories, advances in both observational techniques and the means of producing “artificial lightning” discharges quickened the pace of lightning research.
Observational Advances
Oscillographs enabled visualizing variations in electrical voltage or current, which was really important for simulating lightning accurately in the laboratory. Observations of natural lightning enabled the definition of a “standard surge waveform,” which impulse generators tried to reproduce.
Similar to old televisions, oscillographs used a cathode ray tube to trace an electron beam on photographic film. These traces were called oscillograms. The first oscillographs arrived at Pittsfield in 1924. Four years later, High Voltage Laboratory personnel reportedly recorded the first oscillogram of natural lightning at Lake Wallenpaupack, Pennsylvania.
Oscillograph, undated
This “cold-cathode” device was capable of producing photographic records of extremely short-duration surges.
General Electric Co., in Transformers at Pittsfield (part II)
HC-25 oscillograph, undated
In use until well into the 1970s, this later “hot-cathode” oscillograph recorded impulse discharges in an external camera, which made changing the film much quicker and easier.
Berkshire Athenaeum, Pittsfield, MA, in Transformers at Pittsfield (part II)
In 1935 engineers at the GE High Voltage Laboratory began a series of photographic observations and oscillogram recordings of lightning striking the Empire State Building in New York, the world’s tallest building at the time.
They developed and employed several variations of the high-speed camera originally invented by the British physicist Sir Charles Vernon Boys in 1900, in which the film moved rapidly past the lens. GE’s Boys-type cameras produced some of the earliest and most iconographic lightning photographs.
High-speed cameras made it possible to determine the propagation characteristics of lightning, including leaders and return strokes.
Boys-type camera, 1938
Set up on an upper floor of 500 5th Ave, 8 blocks from the Empire State Building.
The Berkshire Eagle
Second Boys-type camera, 1938
On the roof of the Printers Craft building, 8th Ave and 34th St., at right angles to the 5th Ave camera.
Museum of Innovation and Science
View of the Empire State Building from the second camera, 1938
Museum of Innovation and Science
Lightning strikes the Empire State Building, 1939
Still- and moving-lens records of lightning strokes from 1939. The central image is what an observer would see, whereas the outer image depicts the same stroke over the course of a second or so.
Karl B. McEachron, Playing with Lightning (1940)
Lightning strikes the Empire State Building, 1939
Another photograph of lightning striking the Empire State Building.
Museum of Science and Innovation
Impulse Testing
The purpose of impulse testing is to demonstrate the ability of electrical apparatus to withstand high current surges inflicted by lightning. A typical impulse generator during the 1920s looked like this one million-volt DC surge set from the Trafford High Voltage lab.
Westinghouse surge set, 1927
Trafford Historical Society Westinghouse Collection
In 1924 the German electrical engineer Erwin Otto Marx improved on this “stair-step” design by devising a circuit capable of producing high voltage surges from a much lower voltage DC supply. New, more powerful impulse generators based on this circuit facilitated the design of protecting gaps and arcing horns capable of “interrupting” lightning overloads.
During the 1930s GE developed a modern form of vertical impulse generator that consisted of insulated, cylindrical capacitor units mounted vertically in a Marx circuit.
These 5000kV impulse generators became known as the “World’s Fair” design following their use for spectacular demonstrations at the 1939 World’s Fair in New York, where “Steinmetz Hall” in the General Electric Building garnered some of the most publicity.
Thirty-foot arc, 1938
Engineers from the high voltage laboratory put on awe-inspiring public shows at the 1939 World’s Fair that included a 30-foot artificial lightning discharge like this one the previous year. The impulse generators were charged to 300kV by “Kenotron” high-vacuum rectifier tubes (glowing brightly in the photograph) fed by two transformers: one for the charging voltage, the other to light the tube filaments.
The Berkshire Eagle
Impulse generator in new GE high voltage lab, 1949
Parts of the 1939 “World’s Fair” impulse generators were reconstructed into the pair designed for the new high voltage laboratory at the Pittsfield plant in 1949.
Andreas Feininger/Life Magazine
Impulse generator, inside view, 1952
The six columns of cylindrical capacitor units in each generator were connected in series via ball spark gaps in the interior.
Museum of Science and Innovation
Marx circuit for GE’s “World’s Fair” impulse generators, 1939
It worked by charging a bank of capacitors arranged in parallel and then discharging them in series. This multiplied the initial DC voltage by the number of capacitors in the bank.
General Electric Review, 1939
GE’s Lightning Circus
During the 1940s and 50s, the GE High Voltage Laboratory in Pittsfield was known throughout the United States as a center of lightning research. By this time GE had become a household name in high-tech, domestic electrical goods, from refrigerators to radios. Like other electrical manufacturers, GE sought to stoke consumer demand by appealing to the imagination.
In 1949 the company reprised its World’s Fair demonstrations when it opened “Building 9,” a 75-foot tall high voltage laboratory on its Pittsfield site. The new facility served research and development into insulating structures and transformer-related equipment. GE’s efforts at self-promotion sought to connect these demonstrations of power over nature with its ability to realize a utopian, technological future.
GE Executive Robert Paxton addresses the crowd on the progress of lightning research at the dedication of the new Pittsfield High Voltage laboratory on June 23, 1949.
Museum of Science and Innovation
Opening day, “Building 9” High Voltage Lab, June 23, 1949
Julius Hagenguth, Chief Engineer of the High Voltage Lab (left) and Karl B. McEachron, Assistant Manager of Engineering for the GE Transformer and Allied Product Division (right), pose with equipment on the lab’s opening day.
The Berkshire Eagle
Press gather with their film cameras in anticipation
Life Magazine photographer Andreas Feininger captured the sublimity and grandeur of the impulse generators, cascade transformers and the phenomena they produced.
Andreas Feininger/Life Magazine
“World’s Fair” Impulse Generator
Gigantic bay doors and an electrically-driven wagon made one of the generators capable of testing outdoors.
Andreas Feininger/Life Magazine
One million volt, three-phase arc
Three pairs of cascade transformers powered the one million volt three-phase arc. The rotating electrodes were treated chemically in order to produce three vibrant colors for visual effect.
Andreas Feininger/Life Magazine
Lightning rod protects a model village
Promoting the essential value of GE’s lightning research to the safety of people and property, a 7500kV discharge from one of the impulse generators travels harmlessly to ground after striking a lightning rod.
Andreas Feininger/Life Magazine
Fifteen-million volt discharge
In order to generate the shower of sparks, the current from the combined 15MV discharge had to be adjusted carefully, otherwise the conductor would simply vaporize. Transmission lines underwent similar tests to determine how much current they could carry.
Andreas Feininger/Life Magazine
The appearance of the room, with the house lights lowered and red signal-lights glowing, with the tall forbidding stacks of black and chromium from which protruded shiny sphere-capped rods in weird profusion, was enough in itself to quicken the lay-watcher’s pulse.
Karl B. McEachron
High Voltage, 1949
British Pathé newsreel of the GE artificial lightning demonstrations at the opening of Building 9.
British Pathé
General Electric Theater
From 1954 to 1962 Ronald Reagan hosted General Electric Theater, a highly popular CBS radio and television show. Reagan traveled to over 130 GE laboratories and factories to promote the company’s research, engineering and manufacturing.
Ronald Reagan visits GE’s High Voltage Lab, 1955
Ronald Reagan gazes upwards at one of the GE impulse generators in 1955, illuminated by its “Kenotron” rectifier tubes.
The Berkshire Eagle
Challenging Environments
The postwar integration of regional grids and continually increasing demand for electricity continued to drive transmission voltages higher throughout the 1950s and 1960s. Pushed to their limits during peak hours, North American electrical utility companies worked together to bring new, more massive steam turbogenerators online. Networks of the “power pools” thus formed covered areas greater than the largest European nations and included parts of Canada to the North and Mexico to the South.
Voltage Heads Higher
Westinghouse worked in partnership with the Virginia Electric Power Company (VEPCO) to develop the first 500kV transmission system. In 1958, GE embarked upon “Project EHV” (Extra High Voltage), a five-mile overhead test transmission line near Lenox, Massachusetts, energized at 770kV. These initiatives relied upon new outdoor test areas and even larger, sometimes environmentally-controlled, indoor facilities.
Project EHV’s “Bubble,” 1962
From 1961 impulse tests for Project EHV could be carried out in damp weather using a 3000kV impulse generator housed in a fabric “bubble,” kept up by air pressure from a blower.
General Electric Co., in Transformers at Pittsfield (part I)
Westinghouse outdoor EHV test area, 1964
Outdoor impulse tests, like this one at the Westinghouse in 1964, eliminated the risk of stray discharges terminating on the building walls.
Detre Library and Archives, Heinz History Center
In 1968 GE began to operate an outdoor high voltage testing area known as Area 72 equipped with three 500kV cascade transformers, an oil testing tank, and an 80-foot impulse generator.
Area 72 cascade transformers and bushing test tank, around 1968
General Electric Co., in Transformers at Pittsfield (part II)
Area 72 outdoor impulse generator, around 1968
Dry, filtered air blown up through its enclosed inner stack enabled the impulse generator to maintain voltages up to 5000kV.
General Electric Co., in Transformers at Pittsfield (part II)
In 1970 Westinghouse opened an indoor extra high voltage testing laboratory adjacent to its outdoor testing area. Three times the size of the original one, it was built mainly to test circuit breakers at ratings up to 765kV. The laboratory enabled EHV equipment to undergo “wet tests” without fear of disruption due to light winds.
Westinghouse indoor EHV lab, around 1970s
Two Westinghouse engineers inspect what look like EHV polymeric surge arresters in the new Westinghouse EHV laboratory.
Detre Library and Archives, Heinz History Center
Power Shifts Overseas
By the end of the 1970s, American Electric Power (AEP) had built the first 765kV extra high voltage (EHV) transmission system in the United States. This marked a high point for the high voltage laboratories.
A combination of the oil crises of the 1970s and foreign competition led to a collapse in the domestic transformer and power circuit breaker markets. By 1987, both the Westinghouse Trafford and GE Pittsfield manufacturing plants had closed, taking the high voltage laboratories with them.
Their legacy lies in the modern electrical infrastructure all around us.
Special Thanks
Jeff Behary
Andrew Capets, Trafford Historical Society
Chris Hunter, Museum of Innovation and Science
Kevin Moran, The Berkshire Eagle