INFORMATION - New High-Speed Drill Penetrates Rocks by Melting Them


               UNITED STATES DEPARTMENT OF THE INTERIOR
                          GEOLOGICAL SURVEY
                      WATER RESOURCES DIVISION
                      WASHINGTON, D. C.  20242

                                                  June 30, 1965
                                                 Code 4050 0001


GROUND WATER BRANCH TECHNICAL MEMORANDUM NO. 4

To:       District Chiefs and Staff Officials, WRD

From:     Acting Chief, Ground Water Branch

Subject:  INFORMATION - New High-Speed Drill Penetrates Rocks by
                        Melting Them

Several districts have expressed interest in a recent Department
of Commerce news release pertaining to use of a red-hot drill bit
to drill basaltic rocks.  The release is reproduced here inasmuch
as copies are not available.  Note that a report on the drilling
technique may be ordered from the U.S. Department of Commerce.

A radically new high-speed drill that penetrates rocks by melting
them has been constructed and successfully tested by researchers
of Los Alamos Scientific Laboratory.

The drill is especially designed to penetrate layers of hard
basaltic rock, which create numerous difficulties for oil
drillers, geologists, and others using conventional drilling
methods.  A report describing the drill has just been made
available to the public by the U.S. Department of Commerce through
the Clearinghouse for Federal Scientific and Technical
Information.

According to the Los Alamos developers, the new drill glides
through hard basaltic rock like a hot knife goes through butter at
the remarkable rate of 50 feet per day.  This compares with the
two to four feet per day often encountered with conventional
drills in the harder rock formations.

A host of potential applications exists for the drill in mining
and excavating for oil and minerals, in quarrying, and in
tunneling.  Geologists in particular should welcome the device as
an aid for geological research of the earth's rock formations.

In the test drill, researchers used molybdenum as the red-hot
drill bit to melt the rock.  It is heated to about 1700 degrees
Celsius, well above the melting point of steel and most basaltic
rocks.  The researchers applied the heat electrically at the rate
of 15 volts and 150 amperes from a small commercial welding
transformer.  A tungsten plate heater at the base of the drill
heats to incandescence and transmits the heat to the molybdenum
drill bit.

In contact with the molybdenum drill bit, basaltic rocks melt to
lava, which is then ejected by being blown up the central core of
the drilling apparatus by streams of gas.  Molybdenum is ideal for
the drill bit because it exhibits excellent strength and
resistance to corrosion at the high temperatures needed for rock
melting, but tungsten is also a candidate since it has even
greater strength and corrosion resistance at such temperatures.

To get the report, Order LA-3243N, ROCK MELTING AS A DRILLING
TECHNIQUE, prepared by Los Alamos Scientific Laboratory, Mar.
1965, 39 pages, price $2.00, from the Clearinghouse, U. S.
Department of Commerce, Springfield, Va.  22151.



                                   (s) Gerald Meyer

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