Glomar Challenger: Drillship of the Deep Sea Drilling Project

It was on June 24, 1966, that the Prime Contract between the National Science Foundation and The Regents, University of California was signed. This contract began Phase I of the Deep Sea Drilling Project which was based out of Scripps Institution of Oceanography at the University of California, San Diego. Global Marine, Inc. performed the actual drilling and coring.

The Levingston Shipbuilding Company laid the keel of the D/V Glomar Challenger on October 18, 1967, in Orange, Texas. The ship was launched on March 23, 1968, from that city. It sailed down the Sabine River to the Gulf of Mexico, and after a period of testing, the Deep Sea Drilling Project accepted the ship on August 11, 1968.

Over the next 30 months, Phase II consisted of drilling and coring in the Atlantic, Pacific, and Indian oceans as well as the Mediterranean and Red Seas. Technical and scientific reports followed during a ten month period. Phase II ended on August 11, 1972, and ship began a successful scientific and engineering career.

The success of the Challenger was almost immediate. On Leg 1 Site 2 under a water depth of 1067 m (3500 ft), core samples revealed the existence of salt domes. Oil companies received samples after an agreement to publish their analyses. The potential of oil beneath deep ocean salt domes remains an important avenue for commercial development today.

But the purpose of the Glomar Challenger was scientific exploration. One of the most important discoveries was made during Leg 3. The crew drilled 17 holes at 10 different sites along a oceanic ridge between South America and Africa. The core samples retrieved provided definitive proof for continential drift and seafloor renewal at rift zones. This confirmation of Alfred Wegener's theory of continental drift strengthened the proposal of a single, ancient land mass, which is called Pangaea. The samples gave further evidence to support the plate tectonics theory of W. Jason Morgan and Xavier Le Pichon. The theory of these two geologists attempts to explain the formation of mountain ranges, earthquakes, and deep sea trenches.

Another discovery was how youthful the ocean floor is in comparison to Earth's geologic history. After analysis of samples, scientists concluded that the ocean floor is probably no older than 200 million years. This is in comparison with the 4.5 billion years of our Earth. As the seafloor spreads from the rifts, it descends again beneath tectonic plates or is pushed upwards to form mountain ranges.

The ship retrieved core samples in 30 ft long cores with a diameter of 2.5 in. These cores are stored at the Lamont-Doherty Earth Observatory (LDEO) at Columbia University and at Scripps Institution of Oceanography. After splitting the core in half length-wise, one half was archived and the other is still used as a source to answer specimen requests.

Although itself a remarkable engineering feat, the Challenger was the site of many advances in deep ocean drilling. One problem solved was the replacement of worn drill bits. A length of pipe suspended from the ship down to the bottom of the sea might have been as long as 20,483 ft (6243 m)(as was done on Leg 23 Site 222). The maximum depth penetrated through the ocean bottom could have been as great as 4,262 ft (1299 m)(as at Site 222). To replace the bit, the drill string must be raised, a new bit attached, and the string remade down to the bottom. However, the crew must thread this string back into the same drill hole. The technique for this formidable task was accomplished on June 14, 1970, in the Atlantic Ocean in 10,000 ft (3048 m) of water off the coast of New York. This re-entry was accomplished with the use of sonar scanning equipment and a re-entry cone which had a diameter of 16 ft (4.88 m) and height of 14 ft (4.27 m).

The Glomar Challenger tied dock for the last time with the Deep Sea Drilling Project in November 1983. Parts of the ship, such as its dynamic positioning system, engine telegraph, and thruster console, are stored at the Smithsonian Institution. From August 11, 1968, to November 11, 1983 an impressive list of statistics were compiled:

With the advent of larger and more advanced drilling ships, the JOIDES Resolution replaced the Glomar Challenger in January 1985. The new project, called the Ocean Drilling Program (ODP), continues exploring Earth's history beneath the oceans.

Struhs, A. "Glomar Challenger unlocks the earth's mysteries" On Location (Winter 1984), 8-12.