Page 5: of Maritime Reporter Magazine (January 15, 1974)

Litton's Erie Marine

Division Delivers

The Presque Isle

The Self-Unloading 1,000-Foot

Tug/Barge Combination Transports 50,000 Tons Of Iron-Ore Pellets

Per Trip And Unloads At Rates

Up To 10,000 Tons Per Hour

Presque Isle leaving Litton's Erie Marine Division on her maiden voyage.

Th-e world's largest tug-barge—-Litton In- dustries' 1000-foot-long Presque Isle—-sailed into the Gary, Indiana harbor of U.S. Steel

Corporation on December 26 to deliver her first 50,000 ton cargo of iron ore after her 700-mile voyage from Two Harbors, Minn.

When the Presque Isle arrived at Gary, she offloaded her huge cargo at the rate of about 10,000 tons per hour. Each trip will deliver enough iron ore for the manufacture of about 10,000 automobiles.

The tug-barge is committed to a long-term transport contract with U.S. Steel Corpora- tion. She will sail between the steel com- pany's facilities in Gary and Two Harbors, completing the round trip in less than six days.

The giant $35 million vessel was built by the Erie Marine division of Litton Industries, at Erie, Pa. Her 1000-foot length is seven times the height of Gary's Downtown Holiday

Inn, or two-thirds the 1450-foot height of the world's tallest building, the new Sears unit in

Chicago.

The barge measures 975 feet long by 105 feet wide, with 28J/2 foot draft. The pusher tug, built to Litton specifications by Halter

Marine Services, Inc., New Orleans, is 152 feet long by 54 feet wide by 75 feet high. The pusher tug fits and locks into a specially de- signed notch at the stern of the barge, and the integrated vessel is 1000 feet long.

The tug's two 7500-hp Mirrlees Blackstone diesel engines, supplied by Hawker Siddeley,

Ontario, Canada, propel the huge tug-barge at a speed of 15 mph (or 13 knots). The tug's 250-foot unloading boom was designed and built by the Hewitt-Robins division of Litton.

This $35 million vessel involved the talents of many firms during its design and construc- tion. Marine Consultants and Designers, Inc. was assigned the technical responsibility for the complete design of the barge and the ma- chinery and electrical components of the tug, together with total responsibility for coordi- nation of the complete design project.

Breit Engineering was retained to design the hull, outfit all necessary connection hard- ware for the tug and also the configuration and structural requirements of the barge notch.

Hewitt-Robins, a division of Litton Indus- tries, was assigned the task of studying vari- ous subsystems and finalizing the design of the complete unloading system for the barge.

The bow section of the barge was contracted to Defoe Shipbuilding Company of Bay City,

Mich. The 'bow was built to a length of 68 feet and out to the full beam of slightly less than the midbody molded beam of 104 feet 7 inches. The bow as completed by Defoe was essentially fully outfitted and finished, includ- (Continued on page 8)

Mrs. Ralph W. Biggs Jr., wife of the yard's general manar ger, christens the Presque Isle. Her matrons of honor are Mrs. Ralph A. Whitaker, wife of Erie Marine's mana- ger of administration (center), and Mrs. Keith Branton, wife of the general superintendent of the shipyard.

Overall view of the Presque Isle engine room taken across the top of the Mirrlees Black- Chief engineer Oscar W. Garnett monitoring the tug's propulsion plant from the central stone KV-16 main engines, each developing 7,500 bhp, supplied by Hawker Siddeley. control panel located on the flat in the engine room. The room is air-conditioned.

January 15, 1974 7