Operation CHASE (an acronym for "Cut Holes And Sink 'Em") was a United States Department of Defense program for the disposal of unwanted munitions at sea from May 1964 until the early 1970s.[1][2] Munitions were loaded onto ships to bescuttled once they were at least 250 miles (400km) offshore.[3][4] While most of the sinkings involved conventional weapons, four of them involvedchemical weapons.[3] The disposal site for the chemical weapons was a three-mile (5 km) area of the Atlantic Ocean between the coast of the U.S. state ofFlorida and theBahamas.[5] Other weapons were disposed of in various locations in the Atlantic and Pacific oceans. The CHASE program was preceded by the United States Army disposal of 8,000short tons ofmustard andlewisite chemical warfare gas aboard the scuttled SSWilliam C. Ralston in April 1958.[1][6] These ships were sunk by havingExplosive Ordnance Disposal (EOD) teams openseacocks on the ship after they arrived at the disposal site. The typicalLiberty ship sank about three hours after the seacocks were opened.[1]
Themothballed C-3Liberty shipJohn F. Shafroth was taken from theNational Defense Reserve Fleet atSuisun Bay and towed to theConcord Naval Weapons Station for stripping and loading. A major fraction of the munitions in CHASE 1 wasBofors 40 mm gunammunition from theNaval Ammunition Depot atHastings, Nebraska. CHASE 1 also includedbombs,torpedowarheads,naval mines,cartridges,projectiles,fuzes,detonators,boosters, overageUGM-27 Polaris motors, and a quantity of contaminated cake mix an army court had ordered dumped at sea.Shafroth was sunk 47 miles (76 km) off San Francisco on 23 July 1964 with 9,799 tons of munitions.[1]
Village was loaded with 7,348 short tons of munitions at theNaval Weapons Station Earle and towed to a deep-water dump site on 17 September 1964. There were three large and unexpected detonations five minutes afterVillage slipped beneath the surface. An oil slick and some debris appeared on the surface. The explosion registered on seismic equipment all over the world. Inquiries were received regarding seismic activity off the east coast of the United States, and theOffice of Naval Research andAdvanced Research Projects Agency expressed interest in measuring the differences between seismic shocks and underwater explosive detonations to detect underwater nuclear detonations then banned by treaty.[1]
Coastal Mariner was loaded with 4040short tons of munitions at theNaval Weapons Station Earle. The munitions included 512 tons of explosives. FourSOFAR bombs were packed in the explosives cargo hold with booster charges of 500pounds (227kg) of TNT to detonate the cargo at a depth of 1,000 feet (300 m). The United States Coast Guard issued a notice to mariners and the United States Department of Fish and Wildlife and the United States Bureau of Commercial Fisheries sent observers. The explosives detonated seventeen seconds afterCoastal Mariner slipped below the surface on 14 July 1965. The detonation created a 600-foot (200m) waterspout but was not deep enough to be recorded on seismic instruments.[1]
Santiago Iglesias was loaded with 8,715 tons of munitions at theNaval Weapons Station Earle, rigged for detonation at 1,000 feet (300 m), and detonated 31 seconds after sinking on 16 September 1965.[1]
Isaac Van Zandt was loaded with 8,000 tons of munitions (including 400 tons of high explosives) at theNaval Base Kitsap and rigged for detonation at 4,000 feet (1.2 km). On 23 May 1966 the tow cable parted en route to the planned disposal area. Navy tugsUSSTatnuck (ATA-195) andUSSKoka (ATA-185) recovered the tow within six hours, but the location of sinking was changed by the delay.[1]
Different sources describe CHASE 6 differently.Naval InstituteProceedings indicatesHorace Greeley was loaded at theNaval Weapons Station Earle, rigged for detonation at 4,000 feet (1.2 km), and detonated on 28 July 1966.[1] Other sources describe CHASE 6 as the Liberty shipRobert Louis Stevenson loaded with 2,000 tons of explosives atNaval Base Kitsap in July 1967 as part of the ONR and ARPA investigation to detect underwater nuclear tests.Robert Louis Stevenson failed to sink as rapidly as had been predicted and drifted into water too shallow to actuate the hydrostatic-pressure detonators. The tugTatnuck involved in towingRobert Louis Stevenson was reported byProceedings as towingIzaac Van Zandt a year earlier for CHASE 5.[7]
Michael J. Monahan was loaded with overageUGM-27 Polaris motors at theNaval Weapons Station Charleston and sunk without detonation on 30 April 1967.[1]
The first chemical weapons disposal via the program was in 1967 and designated CHASE 8. CHASE 8 disposed ofmustard gas andGB-filledM-55 rockets. All of the cargo was placed aboard a merchant hulk (the S.S.CorporalEric G. Gibson) and was then sunk in deep water off the continental shelf.[3]
Eric G. Gibson was sunk on 15 June 1967.[1][8]
CHASE 10 dumped 3,000 tons of United States Armynerve agent filled rockets encased in concrete vaults.[3] The ship used was theLeBaron Russell Briggs.[9]Public controversy delayed CHASE 10 disposal until August 1970. Public awareness of operation CHASE 10 was increased by mass media reporting following delivery of information fromthe Pentagon to the office of U.S. RepresentativeRichard McCarthy in 1969. Both American television and print media followed the story with heavy coverage. In 1970, 58 separate reports were aired on the three major network news programs onNBC,ABC andCBS concerning Operation CHASE. Similarly,The New York Times included Operation CHASE coverage in 42 separate issues during 1970, 21 of those in the month of August.[5] The publicity played a role in ending the practice of dumping chemical weapons at sea.[citation needed]
CHASE 11 occurred in June 1968 and disposed of United States Army GB andVX, all sealed in tin containers.[3]
CHASE 12, in August 1968, again disposed of United States Army mustard agent and was numerically (although not chronologically) the final mission to dispose of chemical weapons.[3]
Operation CHASE was exposed to the public during a time when the army, especially theChemical Corps, was under increasing public criticism. CHASE was one of the incidents which led to the near disbanding of theChemical Corps in the aftermath of theVietnam War. Concerns were raised over the program's effect on the ocean environment as well as the risk of chemical weapons washing up on shore.[4] The concerns led to theMarine Protection, Research, and Sanctuaries Act of 1972, which prohibited such future missions.[3] After a treaty was drafted by theUnited Nations' London Convention in 1972, an international ban came into effect as well.[10]