Mobile Drilling Units: Jackup Rigs

Offshore Rig 51 was the first self-elevating drilling unit. It went into service in 1954. The Offshore Company was developed as a joint venture with Southern Production (now SONAT), J. Ray McDermott and DeLong. Based on the DeLong jacking system the rig had 10 legs, each 6 ft in diameter and 160 ft long, with large spud cans to limit penetration into the seafloor. By means of a jacking and holding mechanism, the barge pulled itself out of the water, safely above the waves.

Mr. Gus was a Bethlehem design, self elevating unit and was built in 1954 for C. G. Glasscock Drilling Co. intended for 100 ft water depth operations. The forerunner of today's fleet of jackups was the Scorpion. Designed by R. G. Le Tourneau and built by the Le Tourneau Company in 1956, it was a triangular platform with 3 trussed legs. Each leg had a full length gear rack to engage the pinions of the elevating mechanism. Pinions were driven by powerful electric motors equipped with electromagnetic brakes. The Zapata Offshore Co., who had the foresight to purchase this innovative jackup design, was headed by future US President George Bush.

Recognizing the pioneering efforts of the following people and companies who contributed to the development of this technology:

George H. W. Bush, Colonel Leon B. DeLong, Charles G. "Mr. Gus" Glassock, Robert G. Le Tourneau, Ralph Thomas "J. Ray" McDermott, F. "Tim" Pease, James E. Steele, James C. "Jimmy" Storm Bethlehem Steel, Le Tourneau Inc., J. Ray McDermott Co., The Offshore Co. (Transocean Inc.), Zapata Offshore Co. (Diamond Offshore)