Westinghouse Atom Smasher

The Westinghouse Atom Smasher was an electrostatic nuclear accelerator operated by the Westinghouse Electric Corporation at their Research Laboratories in Forest Hills, Pennsylvania. The 5 MeV electrostatic nuclear accelerator was instrumental in the development of applications of nuclear science for energy production and marked the beginning of nuclear research for civilian applications.


The Van de Graaff generator, an endless rubber or fabric belt that carried electric charges from a roller at the base to a hollow metal electrode, was invented in 1929 by Robert J. Van de Graaff. 1 The device caused a high voltage to develop between electrodes at the top and bottom of the apparatus.

In 1937, the device was adopted by Westinghouse’s Dr. William E. Schoupp, 19 whereas two high-speed belts traveled up a 47-foot shaft to a mushroom-shaped electrode where electric charges were accumulated. 2 3 4 Various ions, such as those generated from helium or hydrogen gas, were injected into the upper part of an accelerator tube. The high electrostatic potential between the top and bottom of the tube caused the subatomic particles to accelerate to high velocities as they traveled down a 40-foot-long, 17-inch diameter evacuated cylinder in what was the largest vacuum tube in the world. 6 16 The accelerator tube ran between and parallel to the belts to the base of the machine, where the accelerated particles bombarded experimental targets placed inside the tube at 30 million to 100 million miles per hour 18 to induce various nuclear reactions. 1 5 17 19 The energy of the particles was measured through the gamma rays that the beam produced when it was particles hit a fluorine target. 5

The 5 MeV electrostatic nuclear accelerator was instrumental in the development of applications of nuclear science for energy production, 8 9 10 and marked the beginning of nuclear research for civilian applications. 11 12 In 1940, the atom smasher was used to discover the photofission of thorium and uranium. 6 7

Westinghouse Atom Smasher
Source: Detre Library & Archives at the Heinz History Center

Westinghouse’s focus shifted towards defense work during World War II. 15 18 Nuclear research became highly classified with operations moving to government-operated operations at Los Alamos and Oak Ridge. With the atom smasher too large to move, it was decommissioned and the tank was used to store compressed air for jet propulsion research. In 1946, after the war concluded, the atom smasher was refurbished, which included painting the tank and the installation of high-speed oil diffusion pumps to exhaust air from the vacuum tube. 18

In September 1956, Westinghouse announced that a more powerful Van de Graaff atom smasher would be built at the company’s new research laboratories in Churchill. 20 22 With a capacity of 7 MeV, it was designed to augment but not replace the Forest Hill atom smasher, but it was clear that it had become obsolete. 3

The atom smasher was used to break ground for the first industry-owned nuclear materials testing reactor at Waltz Mill on July 8, 1957. 21 A Geiger counter recorded the generation of neutrons. The audible clicks of the counter were transmitted 20 miles over a special telephone line to Waltz Mill, where an electrical circuit was interrupted which caused a titanium spade to drop into the ground.

The Forest Hills atom smasher was formally decommissioned by Dr. Schoupp on October 22, 1958, which included a brief ceremony that included the opening of a valve that allowed compressed air to escape from the machine. 19 At the same time, the company unveiled a testing reactor, its newest research device, designed to determine to effects of radiation on various metals that may be used inside power reactors.

In February 1994, Westinghouse discovered low levels of radioactivity in approximately a fourth of the subfloor of a building’s fourth floor. 24 The circa 1920 structure housed the company’s research and development center, which included work on the Manhattan Project in the 1940s. No further work with radioactive material was conducted at the site since the 1950s. The original oak flooring was removed and disposed of.

Decline of Westinghouse

During the 1960s and 1970s, Westinghouse expanded to become a diversified conglomerate by adding financial and real estate businesses to its portfolio. 26 At its peak, the company featured 135 divisions. Financial problems led the company to downsize to just 23 business units by 1987, with further reductions taking place in the real estate and Westinghouse Credit Corporation arms in the early 1990s.

The Forest Hills laboratory continued operations until 1995 when Westinghouse bought CBS for $5.4 billion in 1995, then sold its industrial assets 15 25 and became CBS on December 1, 1997. 26 The laboratory was formally closed in 1996 15 and the Nuclear Regulatory Commission cleared the site for unrestricted use in 2001. 17 27

By 2004, then-owner Viacom was seeking to find new uses for the Forest Hills laboratory and could not find any interested buyers in either the property or the iconic atom smasher. 16 The Carnegie Science Center, Senator John Heinz Pittsburgh Regional History Center, and Smithsonian Institute all declined to take the atom smasher as-is because of its massive size. 16 28

The derelict property was purchased by P&L Investments in January for $200,000. 13 27 28 The developer had proposed to save the atom smasher and build apartments or home storage units on the former laboratory site. 14 29 A local school had hoped to convert the building into an educational center, but because of structural deterioration and high costs of $3 million to $5 million, the atom smasher was removed from its supports and laid on its side on January 20, 2015. 8 28 29 Workers laid bricks to brace the fall and tipped it over. 3


One of the original research fellows at the Forest Hills laboratory, Dr. Shoupp, helped the company become a leader in nuclear research thanks to his assistance in the development of the atom smasher. 19 Dr. Shoupp’s research was also vital toward the development of nuclear reactors in submarine propulsion (Nautilus) and the buildout of the first commercial nuclear plant in the United States at Shippingport in 1957. 16 23

The development 5 MeV electrostatic nuclear accelerator by Westinghouse was instrumental in the development of applications of nuclear science for energy production, 8 9 10 and marked the beginning of nuclear research for civilian applications. 11 12 In 1940, the atom smasher was used to discover the photofission of thorium and uranium. 6 7 Also in the year, Westinghouse used the explosive force of a single atom of U-235, which started a chain of reactions that switched on a new 50,000-watt transmitter for WBZ radio in Boston. 18

Westinghouse scientists also later added radioactive phosphorus to a test batch of raw steel and sampled it hourly to determine the quantity of phosphorus, as the slightest concentration of the chemical could make steel brittle. 18 The company also produced the first quantity production of metallic uranium for the first atomic stockpile and the first large-scale production of purified zirconium metal for atomic reactors. 23

The atom smasher was named an Electrical Engineering Milestone by the Institute of Electrical and Electronics Engineers in 1985. 6 In 2000, the atom smasher was designated a historically significant landmark by the Pittsburgh History and Landmarks Foundation. 16 28


Further Reading


  1. “Mightiest Atom Smasher.” Life, 1937, pp. 36–39.
  2. Westinghouse Atom Smasher.” Pennsylvania Historical and Museum Commission.
  3. O’Neill, Brian. “With Forest Hills atom smasher’s fall, part of history tumbles.” Pittsburgh Post-Gazette, 15 Jan. 2015.
  4. “Huge generator to smash atoms.” Popular Science, 1937, p. 35.
  5. Chubb, L.W. “Giving Atoms the Third Degree.” Popular Mechanics, 1941, p. 8–11.
  6. Milestones: Westinghouse Atom Smasher, 1937.” Engineering and Technology History Partnership, 29 May 1985.
  7. Haxby, R.O., W.E. Shoupp, W.E. Stephens, and W.H. Wells. “Photo-Fission of Uranium and Thorium.” Physical Review, 1 Jan. 1941.
  8. Klein, Barbara. “Reconstructing Pittsburgh’s Atomic Past.” Carnegie Magazine, Winter 2016.
  9. Van de Graaff particle accelerator, Westinghouse Electric and Manufacturing Co., Pittsburgh, PA, August 7, 1945.” Explore PA History.
  10. Westinghouse Electric Corporation [Science and Invention] Historical Marker.” Explore PA History.
  11. Toker, Franklin. Pittsburgh: A New Portrait. University of Pittsburgh Press, 2009, p. 470.
  12. Fey, Maury and Walt Dollard. “The Echoes from Westinghouse at Forest Hills / Forest Hills Nuclear History.” Atomic Conference, 3 Apr. 2015.
  13. Walter, Marni Blake. “An Unlikely Atomic Landscape: Forest Hills and the Westinghouse Atom Smasher.” Western Pennsylvania History Magazine, 1 Sept. 2015, pp. 36–49.
  14. Harkins, Jill. “Atom smasher in Forest Hills torn down; restoration promised.” Pittsburgh Post-Gazette, 21 Jan. 2015.
  15. Kirsch, Tom. “Westinghouse Atom Smasher.” Opacity, 2016.
  16. “First large-scale industrial atom smasher may meet wrecking ball.” Gettysburg Times, 17 Feb. 2004, p. A2.
  17. O’Neill, Brian. “A smash in the old days, nuclear relic seeks savior.” Pittsburgh Post-Gazette, 20 Jan. 2013, p. A2.
  18. “Peacetime Atom Research Pushed.” Pittsburgh Press, 25 Jun. 1946, p. 32.
  19. “A-Smasher is Formally Retired.” Cincinnati Enquirer, 23 Oct. 1958, p. 4E.
  20. “Westinghouse to Build Big Atom Breaker.” Pittsburgh Post-Gazette, 13 Sept. 1956, p. 1.
  21. “Testing Reactor to Be Started.” Pittsburgh Press, 6 Jul. 1957, p. 2.
  22. “Atom Smasher to be Built.” Pittsburgh Press, 13 Sept. 1956, p. 9.
  23. Yohn, Jeff. “The Atom Works for Peace.” San Bernardino County Sun, 25 Feb. 1958, p. 27.
  24. Hopey, Don. “Westinghouse finds low-level radiation at old nuclear sites.” Pittsburgh Post-Gazette, 23 Feb. 1994, p. D11.
  25. Fitzpatrick, Dan. “RIDC eyes remaining WE Corp. buildings.” Pittsburgh Post-Gazette, 13 Jun. 2000.
  26. Guide to the Westinghouse Electric Corporation Photographs, 1886-1996.” Historic Pittsburgh.
  27. O’Neill, Brian. “Old atom smasher may have future as classroom.” Pittsburgh Post-Gazette, 1 Sept. 2013, p. A2.
  28. “Developer has plans to preserve atom smasher.” Sentinel [Carlisle], 26 Jan. 2015, p. B2.
  29. Hasch, Michael. “Building down, but developer says Westinghouse atom smasher preserved.” TribLive, 20 Jan. 2015.


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