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The atomic age of the 1950s was dominated by the race between the US and the Soviet Union to develop ever more powerful nuclear weapons, as well as parallel efforts to better harness the power of the atom to produce electricity . But another front opened in 1957, when a group of American nuclear scientists proposed the use of nuclear explosives for large-scale earthmoving, an effort known as Project Ploughshare.
One of Plowshare’s earliest spin-offs was Project Chariot, a US Atomic Energy Commission plan to use nuclear explosions to dig a harbor at Cape Thompson, Alaska. The scheme was pushed in 1958 by physicist Edward Teller, director of the commission’s Lawrence Radiation Laboratory (LRL), known today as Lawrence Livermore National Laboratory.
The proposed harbor was to have an entrance channel 6,000 feet long by 1,200 feet wide, leading into an oval “turning basin” more than a mile long by half a mile wide. It was to be created by detonating four 100-kiloton thermonuclear bombs to dig the entrance channel; and two 1-megaton pumps, to excavate the rotating basin. The combined explosive yield of 2.4 megatons would have been 160 times greater than the bomb dropped on Hiroshima. The lab hired Holmes & Narver, a Los Angeles engineering firm, to design Chariot.
As a civilian agency, the commission oversaw both military and non-military nuclear programs. The Joint Committee on Atomic Energy of Congress controlled its budget.
ENR covered Project Plowshare with a series of news articles in the 1950s and 1960s (see links at right), as well as four supporting editorials between 1958 and 1962 related to the effort to assess the utility of nuclear explosives for to construction projects.
Eclipsing Plowshare was the subject of radioactive fallout. Radioactivity from a 1954 hydrogen bomb test at Bikini Atoll in the Pacific Ocean had killed one crew member and poisoned several on a Japanese fishing vessel that was 85 miles from the explosion.
Public concern over the danger of radioactive fallout grew in the years that followed, with chemist and biologist Linus Pauling, a Nobel laureate in chemistry, playing a leading role. During a television interview, he declared that radioactive fallout caused cancer, shocking the audience.
Teller awarded grants to a group of scientists at the University of Alaska to conduct extensive environmental studies for Chariot, hoping to co-opt them. The commission downplayed many of its findings about the potential negative impact of the rainfall on plant and animal life, as well as on the hunting activities of indigenous populations, and delayed the publication of the final report by several years. Three of the scientists lost their jobs.
Project Plowshare’s underground nuclear tests were conducted at the Nevada Test Site north of Las Vegas. A 100 kiloton device was detonated 635 feet underground where it displaced 12 million tons of earth.
Photo courtesy of the US Department of Energy
But several of the scientists shared their concerns with Barry Commoner, a cell biologist and early leader of the environmental movement, who spread his concerns to the scientific community beginning in 1961. That same year, an article in the peer-reviewed journal in pairs science discussed an increase in strontium-90 in children’s teeth after the first US hydrogen bomb test in 1952.
A second Panama Canal?
US officials considered alternative routes to build an alternative to the nuclear-armed Panama Canal.
Chart courtesy of the US Department of Energy
Chariot was intended only as a test for the US government’s larger goal of building a sea-level canal in Central America, as US military leadership feared that the Panama Canal locks would be vulnerable to a nuclear attack. The commission aggressively conducted related investigations and tests for more than a decade.
In May 1959, forty-eight papers on “Possibilities and Problems of Peacetime Uses of Nuclear Explosions” were presented at a Plowshare symposium held in San Francisco. They covered shock patterns, ground motion and thermal effects and avoided groundwater contamination. One paper described the excavation of a lockless canal 59 miles long, 600 feet wide, and 60 feet deep, using 651 nuclear devices. In 1960, Panama Canal Co. hired engineer Parsons, Brinckerhoff, Quade & Douglas to study the use of nuclear weapons to dig a new canal route.
The Carryall Project was a proposed highway and rail excavation that would have been a poster boy for Ploughshare if it had been successful. The Atchison, Topeka and Santa Fe Railroad approached the commission in 1963 about using nuclear blasts to dig a two-mile-long road through the Bristol Mountains in southern California. The California Division of Highways wanted the same route for Interstate 40. Carryall died in 1966 because of the nuclear test ban and a looming deadline for interstate routes.
After several years of informal consultations between the commission and the US Army Corps of Engineers, the two formed a joint program in 1962 to study construction problems related to nuclear weapons. Lt. Col. Robert W. McBride, then deputy director of civil works for the Corps’ nuclear planning, supervised a crater study group at LRL. He and John Kelly, chief of the Commission’s Pacific Nuclear Explosives Division, gave an extensive briefing to ENR reporters at Corps headquarters in Washington, DC, in March 1963.
Eventually, the United States Department of the Interior, which had not been consulted, learned of Project Chariot and objected. At the same time, a nuclear ground test in Nevada in 1962 was found to have spread radioactive dust much farther than intended, further weakening support for Chariot. It was effectively canceled the following month. The project’s final report, published by the commission in 1966, is said to have been “regarded as the first de facto environmental impact statement,” according to the book. The firecracker boys by Dan O’Neill.
The first underground test of Project Plowshare was Project Gnome in New Mexico, conducted in 1961. A 3.1-kiloton weapon was detonated 1,115 feet underground, creating a 99,000-cubic-foot cavern.
Chart and photo courtesy of the US Department of Energy
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Geopolitics and economic concerns played a critical role in restricting the progress of the Ploughshare commission. Disarmament talks between the US, USSR, Great Britain, France and Canada failed to reach an agreement. Soviet Prime Minister Nikita Khrushchev unilaterally offered to suspend nuclear testing in 1958 to pressure the United States to reciprocate. President Dwight D. Eisenhower agreed to a one-year moratorium on new nuclear tests in October 1958. This resulted in several planned underground Plowshare test explosions being put on hold.
Stronger than bombs
Most of the Plowshare and military nuclear tests were conducted at the Nevada Test Site, a 680-square-mile stretch of mountainous desert terrain in southern Nevada, northwest of Las Vegas. Project Sedan in 1962 was Ploughshare’s first nuclear crater explosion. A 100-kiloton device was detonated 635 feet underground where it displaced 12 million tons of earth and left a crater 1,300 feet in diameter and 320 feet deep and sent a debris cloud three miles high . Publicly, the commission highlighted the positive aspects of the test, saying that the crater trapped 95% of the radioactivity while the rest fell near the test site. But the radioactive dust cloud was twice as large, rose significantly higher and “deposited nearly five times more fallout at and near the test site” than the agency had anticipated, according to the book. Project Plowshare by Scott Kaufman.
Despite defeats in Chariot and Carryall, the commission pushed hard for Project Gasbuggy, in which the agency, the US Bureau of Mines and El Paso Natural Gas Co. they tried to demonstrate the feasibility of expanding natural gas fields with nuclear weapons. In 1967, a 26 kiloton explosion detonated 4,240 feet underground in New Mexico made a cavity 150 feet in diameter and 333 feet high and created 2 million cubic feet of space for gas to enter . Initially the results seemed exciting, but tests of the cavity a month later showed that the explosion had changed the composition of the gas to a lower purity and infused it with radioactive tritium, making it unsaleable.
The surface result of an underground nuclear explosion at the Nevada Test Site in 1961.
Photo and graphics courtesy of the US Department of Energy
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US-Soviet test ban talks in the early 1960s led President John F. Kennedy to halt the Plowshare tests to avoid jeopardizing an agreement. To avoid losing momentum in Plowshare, the commission replaced TNT with nuclear devices in several tests, managing to continue collecting useful data. But Glenn Seaborg, the agency’s new chairman in 1961, argued that the proposed US-Soviet treaty did not ban all underground testing. Kennedy signed the Limited Test Ban Treaty in October 1963. The two superpowers would open broader nonproliferation talks the following year, but President Lyndon Johnson’s administration delayed many Plowshare tests to avoid endangering the conversations
Plowshare would also suffer budget cuts during the Johnson era, due to increased spending on the Vietnam War and domestic war on poverty programs. The Richard M. Nixon administration inherited a sizable budget deficit that led to a recession in 1970, and even more cuts. There were 27 Plowshare explosions between 1957 and 1973, consuming increasing amounts of commission funds.
ENR reports that the arrogance of commission officials, their evasiveness on the issue of radioactive fallout, the diplomatic priorities of four successive presidents, and the growing environmental awareness of the American public combined to condemn efforts to use nuclear weapons as tools for mass excavation.
