Project Dugout, a Plowshare Program

On June 24, 1964, Livermore scientists executed “Project Dugout,” as part of a series of “ditching” experiments at the Nevada Test Site. The chemical high explosives blasted a “ditch” or channel with an approximate size of 290 feet long by 129 feet wide, with a depth of about 34 feet. The test was conducted under Livermore’s Plowshare effort — a program established in 1957 to explore the peaceful use of nuclear energy.

The initial focus of the Plowshare Program was on large-scale earth excavation projects, such as the creation of harbors and canals. An emphasis on such Plowshare civil engineering applications was promulgated by international crises like the Egyptian seizure of the Suez Canal in 1956, as well as long-held interests of the Panama Canal Company in the construction of a sea-level canal.

Ditching experiments, like Project Dugout, were designed to develop an understanding of the mechanisms of a row of charges for possible use in the excavation of canals and roadways. One such project under consideration by the Atomic Energy Commission (AEC) for its Plowshare Program was a 1963 feasibility study, designated “Carryall.” The plan, as submitted to the AEC by the California Division of Highways, the Santa Fe Railway, along with technical support from Livermore, envisioned the use of 22 nuclear devices to blast a massive roadcut through the Bristol Mountains to create a more direct route for the construction of Interstate 40 and a rail line.

To put proof to various concepts, the first Plowshare ditching experiments were conducted at the Nevada Test Site from late 1959 through the end of spring 1960. This series of experiments, performed as part of Project Toboggan, involved 122 detonations of chemical high explosives emplaced in playa (dry lakebed). These early tests were designed to study the ditching characteristics of conventional high explosives in preparation for nuclear row-charge experiments.

In June 1961, a further series of chemical row-charge experiments, called “Project Rowboat,” was carried out at the test site and consisted of eight separate experiments each involving the detonation of four 278-pound chemical explosive charges in alluvium (gravel and sand). For Project Dugout, five 20-ton charges of chemical high explosives were detonated simultaneously in hard rock – the first experiment of its type to involve row-charge cratering in dense, hard rock. In addition to Livermore tests, the Nuclear Cratering Group of the U.S. Corps of Engineers also conducted several row-charge experiments using chemical explosives in support of the Plowshare excavation program.

In 1968, the Plowshare Program took a major step forward in the development of nuclear excavation technology with the execution of Project Buggy. On March 12, Livermore scientists simultaneously detonated a row of five nuclear explosives, each with the yield of about one kiloton. The effect was an “instant ditch” 355 feet wide, 903 feet long and 113 feet deep. With Buggy, Livermore demonstrated for the first time that the effects of previous conventional tests could be duplicated with nuclear explosions and that the technique, at higher yields, would be well suited to the excavation of harbors, canals and highway passes.

However, by the 1970s, the application of nuclear energy in any form had become a charged issue and support for Plowshare’s pursuit of the peaceful uses of nuclear explosives began to erode. Despite the program’s successes, proliferation barriers, waning industrial interest and public anxiety about the health and environmental effects of nuclear technology all combined to end the program. As such, Project Plowshare was terminated in 1977.