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

Inventions: Thermoblast Flame-Jet Drill

By Lee Michaelides

Inventor: James A. Browning ’44

James Browning ’44
THERMOBLASTER: James Browning ’44 drilled through Antarctica’s 1,400 feet-thick Ross Ice Shelf in nine hours. Photograph courtesy of Robert Bigl.

Scientists drilling into the Ross Ice Shelf of Antarctica can look back at millions of years of the frozen continent’s history. Probably few researchers, however, know of a more recent bit of ice shelf history.

Thirty-five years ago a new kind of drilling technology, dubbed “Thermoblast” by its inventor, Thayer Professor James A. Browning ’44, was successfully field tested on the polar ice. In 1977 Browning’s high-temperature rocket drill pierced the 1,400-foot-thick ice shelf so scientists could study the ocean underneath. Drilling time: nine hours.

Though the drilling was quick, the development of the invention took a few decades. As early as 1955 experiments were being conducted to speed up drilling in frozen material using flame jets.

Browning began a series of experiments in 1962 “to gain a better understanding of the principles governing the ‘cutting’ action of jet flames and to evaluate burning designs already available,” as he reported in a paper, “Use of Internal Burners for Working Permafrost and Ice” at the 1963 Permafrost International Conference.

The Thermoblast in action
DRILL SITE: The Thermoblast in action. Photograph courtesy of Charles R. Bentley; originally printed in Annals of Glaciology and used with permission of the International Glaciological Society.

The idea was that once the process was better understood, burners could be customized for the task. Browning, who had already founded Thermal Dynamics with Thayer colleague Merle Thorpe Th’53 to produce plasma torches, ran tests on blocks of ice and in frozen silt at the U.S. Army Cold Regions Research and Engineering Laboratory in Hanover. As he gathered data, Browning computed the most efficient combinations of fuel, mass, and jet size for drilling in ice and frozen earth. After his success in Antarctica, he secured nearly $240,000 in funding from the National Science Foundation to develop a suspension core drill that would make it possible to use flame-jet technology for another tricky task: studying rock formations under ice caps and glaciers.

Categories: Inventions

Tags: alumni, faculty, history, innovation, research

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