In December of 1978, the Deep Sea Drilling Project, International Phase of Ocean Drilling, deployed the first hydraulically actuated piston corer. This coring system utilized a hydraulic piston principle. Fluid was pumped through the drill pipe, activating a piston driven core barrel which was ejected into the sediment at the rate of approximately 20 feet per second. This extremely high penetration rate effectively decoupled the core barrel from the heave induced vertical motion of the drill string. On completion of each coring operation, the core barrel assembly was retrieved by wireline. The core bit was then "washed" down to the next coring point where the piston coring procedure was repeated. Operational tests conducted in 865 meter water depth curing Leg 64 obtained an almost totally undisturbed and complete section from a l52-meter hole along the Guaymas slope in the central Gulf of California. Variations in climate productivity and circulation for more than 250,000 years were recorded. This paper describes the analysis design, testing and field operation of the hydraulic Piston Coring System.
The Deep Sea Drilling Project (DSDP) began coring in August of 1968. Funding and direction was given by the National Science Foundation's (NSF) Ocean Sediment Coring Program. Their mandate was to increase man's knowledge of the earth's development through an ambitious ocean sediment coring program. The Prime Contract for the Project was executed in 1966 between NSF and the University of California (UC) Board of Regents. Scripps Institution of Oceanography, an integral part of the UC system, was to be responsible for management of the Project. Global Marine Inc. (GMI), through a subcontract with Scripps, was to provide the drilling vessel and crew. Major oceanographic institutions of the United States were called upon to support the proposed drilling program by contributing to the planning of the scientific objectives. The resultant organization became known as "Joint Oceanographic Institutions for Deep Earth Sampling (JOIDES)". These institutions continue to provide scientific guidance for the drilling effort.
Prompted by the vast scientific and technical successes of the first seven years, the Project increased the scope of the coring program to include even deeper penetrations into the ocean floor. International interest in the Project was increasing. Several foreign scientific institutions, excited by past scientific results and confident of future successes, were interested in becoming members of JOIDES. These institutions were willing to contribute financially to the Project in exchange for a greater role in the scientific planning. In 1975, the "International Phase of Ocean Drilling known as IPOD was born. IPOD was an initial three year Deep Crustal Coring program supported both scientifically and financially by the governments of France, Germany, Japan, England and Russia.
The GLOMAR CHALLENGER, with its unique coring procedures, has long been recognized as a major technological achievement in its own right. The 10,500 metric ton drillship utilizes an advanced on-board computer and dual bow and stern thrusters to dynamically position itself.
