Dartmouth Engineer - The Magazine of Thayer School of EngineeringDartmouth Engineer - The Magazine of Thayer School of Engineering

Inventions: Plasma Torch

By Lee Michaelides

Inventor: Professor James Browning ’44

Professor James Browning and the plasma torch
Photograph courtesy of Dartmouth College archives

Half a century ago Thayer Professor James Browning ’44 was nicknamed Hanover’s firebug for his study of flame stability and combustion. In early work on Project Squid, a government-funded study of propulsion, Browning experimented with methyl naphthalene, which smells like gasoline-soaked mothballs. Not only did his lab reek, but news clips from the era reported that as Browning “passed people on the street on his way homeward, he was the subject of many curious glances from people who suddenly realized who was defiling the usually ‘pine-scented’ atmosphere of Hanover.”

Browning will be remembered best not for his smell but for inventions that fired up the Upper Valley economy. In the 1950s he created a plasma torch that produced flames twice as hot as the sun’s surface. Passing nitrogen or hydrogen through a high-intensity electric arc, the torch cut metal like butter. Browning and Thayer colleague Merle Thorpe founded Thermal Dynamics Corp. to manufacture the device. Within three years the start-up had sales of $1 million. A decade later, Thayer Professor Robert Dean and Richard Couch ’64, Th’65 formed Hypertherm Inc. to produce a water-injection plasma torch that was nine times hotter than the sun. Today that company employs 500 people.

Meanwhile, Browning invented a high-temperature rocket drill called the “Thermoblast.” In 1977 he used it to pierce Antarctica’s 1,400-foot-thick Ross Ice Shelf so scientists could study the water underneath. Drilling time: nine hours — a cool use of a hot technology.

For more photos, visit our Research and Innovations set on Flickr.

Categories: Inventions

Tags: alumni, design, energy, entrepreneurship, faculty, history, innovation, research

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