Marathon Introduces Jumbo Bottom-Supported Offshore Platform

As the search for offshore oil and gas moves into progressively harsher environments, the need has developed for a new generation of larger self-elevating jackup drilling platforms specifically designed for such areas.

Marathon LeTourneau Offshore Company, one of the world's leading producers of offshore self-elevating drilling platforms, introduced its new 300-85-class rig at the 1977 OTC in Houston, Texas. The 300-85 is approximately 50 percent larger than Marathon's 84 or 116-class platforms.

As the model number suggests, Marathon's new 300-85 rig is designed to drill in up to 300 feet of water and withstand the combined forces of 85-foot-high waves and sustain 90-knot winds along with a one-knot current. The hull is 303 feet long, 268 feet wide and 30 feet deep, with 200-foot leg centers.

The platform and the legs are raised and lowered by Marathon's electromechanical self-elevating system. The 72-gear units have a nominal elevating capacity of 13,500 tons and 21,600 tons of holding capacity. Continuous elevating speed is up to 90 feet per hour.

Simple push-button controls allow the legs to be raised or lowered separately or simultaneously.

Marathon's electromechanical selfelevating system features continuous engagement between legs and the platform, permitting infinite adjustment and providing fail-safe brakes.

The three 452-foot-long legs are square in cross-section with special high-strength Marathon LeTourneau steel tubular corner posts and structural tube braces. In 300 feet of water, this length provides for a 25-foot ocean bottom penetration and 60-foot air gap, with 5 feet of reserve. Top leg sections, removed for major ocean tows, can all be transported on the deck.

Maximum customer-imposed load is 5,000 tons. Minimum capacities are: fuel oil—8,126 barrels; drill water—7,350 barrels; and potable water—4,312 barrels. Full storm preload is also provided. Quarters are provided for up to 92 men.

Marathon LeTourneau Offshore Company is a subsidiary of Marathon Manufacturing Company, Marathon Building, 600 Jefferson, Houston, Texas 77002. The parent firm is a multi-product company serving industries in marine construction and transportation, heavy equipment and steel products, as well as a group of diversified companies producing chemicals, batteries, and providing paving and utility construction services.

Other stories from June 1977 issue

Content

Maritime Reporter

First published in 1881 Maritime Reporter is the world's largest audited circulation publication serving the global maritime industry.