This exhibit highlights Sandia’s role in the Project

Plowshare exploration of peaceful uses of nuclear

detonations.

This exhibit highlights Sandia’s role in the Project

Plowshare exploration of peaceful uses of nuclear

detonations.
In 1958, the Atomic Energy Commission (AEC) announced the creation of Project Plowshare, a government-sponsored program to

develop peaceful uses for nuclear energy. Plowshare officials proposed using nuclear explosions to dig canals and harbors, mine oil

and gas, and recover important information on cratering, radiation, and seismology. Between 1958 and 1975, the program 

conducted 35 nuclear tests, as well as numerous high explosives (HE) experiments simulating nuclear excavation. Lawrence

Livermore National Laboratory (LLNL) directed Plowshare using the expertise of Sandia National Laboratories (SNL), 

Los Alamos National Laboratory (LANL), Oak Ridge National Laboratory (ORNL), the US Geological Survey (USGS), and the

US Bureau of Mines. SNL played a small but integral role in Project Plowshare.

In 1958, the Atomic Energy Commission (AEC) announced the creation of Project Plowshare, a government-sponsored program to

develop peaceful uses for nuclear energy. Plowshare officials proposed using nuclear explosions to dig canals and harbors, mine oil

and gas, and recover important information on cratering, radiation, and seismology. Between 1958 and 1975, the program 

conducted 35 nuclear tests, as well as numerous high explosives (HE) experiments simulating nuclear excavation. Lawrence

Livermore National Laboratory (LLNL) directed Plowshare using the expertise of Sandia National Laboratories (SNL), 

Los Alamos National Laboratory (LANL), Oak Ridge National Laboratory (ORNL), the US Geological Survey (USGS), and the

US Bureau of Mines. SNL played a small but integral role in Project Plowshare.

rather than weapons.

Photo credit: 

The National Atomic Museum.

Photo credit: The United Nations and the 

Dwight D. Eisenhower Library.

Photo credit: Newsweek

Photo credit: Lawrence Livermore National Laboratory.

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As early as 1939, and with renewed

vigor after WWII, scientists and social

commentators touted the life-transforming potential of nuclear fission.

Suggestions ranged from the practical

to the fantastic. 

In 1957, LLNL invited scientists and engineers from

SNL, LANL, and other entities involved in nuclear

research, to a classified conference at Livermore on the

peaceful uses of nuclear explosives. The next year, the

AEC formally established Project Plowshare to coordinate

efforts for the further development of peaceful applications for nuclear weapons; LLNL led the program. 

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In October 1952, the AEC

exploded Mike, the first large

thermonuclear device, at Enewetak

Atoll in the Pacific. Initially, radioactive fallout precluded many of the

proposed peacetime applications of

nuclear weapons. However, the successful detonation of thermonuclear

weapons—which were considered

cleaner and more efficient than 

the first atomic bombs—fed the

optimism regarding research into

peaceful uses.

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The strongest advocate for the use

of nuclear devices in industrial applications was nuclear physicist Edward

Teller. During WWII, Teller participated in the Manhattan Project.

Then and after the war, he pushed

for the development of thermonuclear weapons. His advocacy led to

the creation of LLNL in 1952. 

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The 1957 Ranier shot, the first underground

nuclear explosion, demonstrated that most

radiation from a nuclear blast could be contained underground. Peaceful uses for nuclear

explosives looked promising.

In 1956, SNL president James McRae

observed the Redwing nuclear test. When he

returned home he asked Luke Vortman, of

the Weapons Effects Department, to explore

the feasibility of substituting nuclear devices

for TNT in a proposed Canadian HE project

to rid Seymour Narrows of Ripple Rock, a

long-standing navigation obstacle in British

Columbia. 

Although conventional explosives were ultimately used in the Ripple Rock explosion,

Vortman's analysis concluded that nuclear

devices could be substituted for TNT 

cheaply and with little additional danger

from either radiation or falling rock.
More than any other Plowshare program, the construction of a sea-level canal across the Isthmus of Panama fired

the imagination of AEC officials, scientists, and engineers. In support of this vision, the AEC proposed a number

of nuclear harbor-building projects as preliminary experiments. However, in 1958, due in part to growing international concerns over radioactive fallout, the US entered into a test moratorium with the USSR. All nuclear 

engineering and nuclear weapons tests were put on hold. Nevertheless, plans for nuclear-constructed harbors and

canals proceeded on paper.

study the feasibility of converting the existing Panama

Canal to a sea-level canal with the use of nuclear

explosives.

Photo credit: IOCC phamphlet citation

“...the United States should press 

forward...in plans and preparations for 

a sea level canal.”

“...the United States should press 

forward...in plans and preparations for 

Photo credit: Lawrence Livermore National Laboratory

Project Chariot proposed detonating five nuclear devices in a row

(a total of 2.4 megatons) to achieve a full-scale harbor at the mouth

of Ogotoruk Creek near Cape Thompson in Alaska.

Howard Rock, an Inupiat artist from Point Hope, founded

the first statewide Native American newspaper, the 

Tundra Times, in response to the Project Chariot 

controversy. 

In 1956, LLNL scientist Harold

Brown considered using nuclear

explosives to construct a sea-level

canal through Israel to replace the

outdated Suez Canal. 

In 1966, SNL conducted meterological

studies from Battery

MacKenzie, a modified

WWI coast artillery station near

the Atlantic entrance to the

Panama Canal, to assess possible

damage from airblast in the 

proposed nuclear construction 

of a new canal.

As early as 1939, the United States'

largest ships could no longer pass

through the locks of the Panama Canal

Zone. In 1942, Congress authorized

the construction of larger locks as an

interim solution, but lock construction

stalled during WWII. After the war,

building larger locks no longer seemed

an adequate solution for modernizing

the Panama Canal. 

In 1958, Plowshare and Alaska Health Department officials

met to discuss the potential health risks associated with

nuclear explosives. Left to right: Richard Bice, SNL; Dr.

Harold Fidler, AEC; Wallace Reynolds, University of

California, Berkeley; Dr. Edward Teller, LLNL; Amos Alter,

Alaska Dept. of Health.

In 1958, officials from LLNL, SNL, and the

AEC flew to Alaska to find a suitable site for

the experiment. Chariot survey team members

enjoyed a carribou barbeque. SNL scientist

Melvin Merritt is seated on the right. 

Alaskan officials initially welcomed

Project Chariot. However, Inupiat

natives living closest to the proposed

blast site organized against the 

experiment. In 1961, the Point Hope

Village Health Council protested that

the detonation would be too close to

their hunting and fishing areas. 

They wrote President Kennedy—

”We are deeply concerned about the

health of our people now and for the

future that is coming." 

In 1962, the Inupiat people succeeded

in halting Project Chariot. However,

plans for a nuclear constructed sealevel canal continued.

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SNL air blast studies predicted potential

glass breakage in Medellin, Columbia, from

the proposed Panama Canal nuclear engineering project.

In 1970, The Inter-Oceanic Canal

Commission concluded that the technical

feasibility of nuclear explosives was

unproved and recommended traditional high

explosives. Other concerns included the

prohibition on atmospheric nuclear testing

included in the 1963 Limited Test Ban

Treaty, the formidable problem of removing

existing populations in the canal zone, and

the possible damage to the environment

from nuclear explosives.

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Photo credit: Ukpeagvik Inupiat Corporation and Tuzzy

Consortium Library of Barrow, Alaska.

Photo credit: IOCC citation

Photo credit: Lawrence Livermore 

National Laboratory

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Project Plowshare initiated 19 formal high explosives (HE) experiments designed to gain important information on cratering, airblast, and ground motion—phenomena that would occur during nuclear excavations of canals and harbors. HE experiments

moved the Panama Canal and Chariot projects forward without violating the test moratorium. SNL scientists participated in HE

tests at the Nevada Test Site (NTS) and also conducted many of their own HE experiments at the Coyote Canyon test facilities

In July 1964, Vortman, with the

help of Walter Hyde of Coyote

Test Operations, built an earth

dam by simultaneously firing two

rows of conventional explosives

in Coyote Canyon. 

Coyote Test Field served as the outdoor laboratory for many

of SNL’s experiments in explosive excavation. In December

1964, Vortman simulated a nuclear excavation using a 1/200

scale model of one of the possible Panama Canal routes at

Caladonia Bay.

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On June 28, 1968, Vortman and Virgil Harris

of SNL Field Test detonated 30,500 lbs of

conventional explosives in Coyote Canyon,

the largest HE experiment held at the site. 

The resulting crater measured 105-feet

and threw out 7,200 tons of earth.

This experiment studied airblast geometry—how depth of burial and size of

charges relate to air-blast pressures of

the explosion.

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Nancy Feight mixed samples used in

the 1959 miniature blast studies.

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The AEC’s range of test facilities offered a variety of soils and rock for high explosive (HE) testing. In addition to the

HE tests conducted in New Mexico at SNL’s Coyote Canyon test facilities, smaller sites were used; for example, the

Pre-Schooner II shot was done in Idaho. Larger cratering tests were conducted at NTS.

The AEC detonated 1,000,000-

pounds of TNT at NTS in

Project Scooter. The resulting

crater measured approximately

300-feet in diameter and was 

80-feet deep.

On September 30,

1965, SNL supplied

blast measurement and

microbaragraph readings

for Pre-Schooner II, an

85-ton liquid nitrogen

explosive detonation

near Bureau River

Canyon, 55 miles outside Twin Falls, Idaho.

Pre-Schooner II provided

preliminary information

for Schooner, a 1968

nuclear event that studied the cratering and

engineering properties of

volcanic rock for future

Plowshare excavation

projects.

In 1966, H. Gerald

Laurenson developed a

new prototype balloon

to measure airblast 

during HE experiments.

The smaller balloon—

72-feet long and 21-feet

in diameter—handled

easier and could lift as

much as 400-pounds of

equipment to an altitude of 500-feet.

Sixteen pressure-sensing stations were

mounted on cables held aloft by a

140-foot helium balloon at PreSchooner II. Balloons acted as skyhooks, holding instrumentation used

to obtain airblast measurements from

HE excavation experiments. 

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Russia ended the voluntary nuclear test moratorium on September 1, 1961. The AEC resumed its nuclear

testing program two weeks later. Project Plowshare immediately began preparations for its first nuclear 

excavation. Project Gnome was the first of 27 nuclear earth-moving experiments conducted for Plowshare

over the succeeding 12 years. In order to use nuclear weapons for excavation projects, Plowshare scientists

had to learn how much nuclear material to use, how deeply it should be buried, and how best to space 

the charges.

The Gnome shot melted over 2,400 tons of rock

and created a hemispheric cavern roughly 160- to

170-feet in diameter. 

Gnome ground zero, 

a 10 by 8-foot room,

1,200 feet below

ground, 25 miles

southeast of Carlsbad,

New Mexico.

Sedan was the first in a series of experiments designed to perfect

the techniques of nuclear excavation. The Sedan explosion

occurred 635-feet below ground. The desert floor formed a

dome 290-feet, moving 12-million tons of rock and leaving

behind a crater 1,200-feet across and 320-feet deep.

The Cabriolet experiment

conducted at NTS formed a

crater 125-feet deep and

400-feet in diameter.

The 1968 Project Buggy test detonated five separate one-kiloton

nuclear devices simultaneously,

creating a 900-foot long canal,

300-feet wide and 80-feet deep.

On January 26, 1968, the AEC detonated

Cabriolet, the fourth nuclear excavation in

the Plowshare series; the test was designed

to study cratering effects in hard rock and

the air-born dispersion of radionuclides.

Cabriolet furnished information on nuclear

excavation techniques to be used in the 

proposed Panama Canal project. 

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On July 6, 1962,

the second and

largest Plowshare

nuclear experiment,

code-named Sedan,

detonated 100 kilotons of nuclear

explosives at NTS.

SNL observers

awaited the Sedan

event.

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Buggy duplicated

the results of the

preliminary HE

experiments held at

Coyote Canyon—

forming ditch-like

craters. 

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Photo credit: Reynolds Electrical & Engineering Company.

Photo credit: Lawrence Livermore 

National Laboratory

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In 1968, Congress began cutting appropriations for Plowshare. Nuclear excavation projects like the new Panama Canal route began

to seem prohibitively expensive and dangerous to the environment. As plans for nuclear excavation disintegrated, Plowshare 

shifted its focus to nuclear mining ventures. The AEC, in partnership with industry, planned experiments to increase the recovery

of natural gas using nuclear explosions. The gas industry used conventional explosives to fracture sandstone reservoirs and release

the gas trapped inside. Scientists theorized that nuclear explosives could double US gas reserves. 

In 1968, Congress began cutting appropriations for Plowshare. Nuclear excavation projects like the new Panama Canal route began

to seem prohibitively expensive and dangerous to the environment. As plans for nuclear excavation disintegrated, Plowshare 

shifted its focus to nuclear mining ventures. The AEC, in partnership with industry, planned experiments to increase the recovery

of natural gas using nuclear explosions. The gas industry used conventional explosives to fracture sandstone reservoirs and release

the gas trapped inside. Scientists theorized that nuclear explosives could double US gas reserves. 

g

from the Rulison explosion.

SNL provided expertise in arming, firing, and earth

motion studies for Gasbuggy, a December 10, 1967,

Plowshare experiment to increase the production of

natural gas mines in Farmington, New Mexico.

Gasbuggy was the joint project of the AEC, El Paso

Natural Gas, and the Department of the Interior.

Luke Vortman being interviewed in October

2000. Although the idea that nuclear devices

could be used in digging and drilling seems 

fantastic today, at the time, the prospect that

nuclear weapons could be put to non-military

uses seemed a worthy venture. In hindsight,

Vortman noted that Plowshare “...was a pretty

wild idea.” Yet, he explained he stayed with the

program because “...if this effort was going to fly

wouldn’t it be great to be a part of it?”

LLNL drawing of

the gas reservoir to

be created by the

Gasbuggy nuclear

test.

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Amid local political protest, the AEC detonated three 33-kiloton devices on May 17, 1973.

Rio Blanco, the third of the nuclear gas stimulation tests, was the last of the Plowshare

experiments. Plowshare scientists had hoped

that Rio Blanco would be the first of a series

of new clean underground nuclear devices.

However, post test water and gas samples from

the site exhibited radioactive contamination.

El Paso Natural

Gas and SNL

instrumentation

sites for Rio

Blanco.

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Dean List lowered canisters of SNL

instrumentation 4,600 feet down into

a drilling hole designed to measure

the shock waves of the explosion.

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Rulison, the second natural gas

nuclear mining experiment, was

held on September 10, 1969, near

Grand Junction, Colorado. The

40-kiloton nuclear device was 

detonated 8,430 feet underground

with no venting of radiation. 

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Photo credit: 

Dames & Moore