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The beginning of the ‘catamaran-tug’

In 1975 the first voyage of a ‘catamaran-tug’ was completed

Port Everglades Towing tugboats equipped with fire hoses greet "Seabulk Challenger” and her integrated barge as they enter harbor on March 6. (Photo: American Shipper)

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FreightWaves explores the archives of American Shipper’s nearly 70-year-old collection of shipping and maritime publications to showcase interesting freight stories of long ago.

In this week’s edition, from the April 1975 issue of American Shipper, FreightWaves looks back at the launch of a new type of ship.

The chrome yellow hull of “Seabulk Challenger” and her integrated barge unit cut a brilliant path through the bright blue waters of the Florida Straits March 6 as the world’s first Catug (Catamaran-Tug) units made their way toward their home at Port Everglades after a maiden voyage from the Gulf.


Though it was built in Texas, the Catug system was conceived and developed in Florida and the tug section bears the home port designation of Port Everglades on her port stern.

Built at a cost of approximately $17,000,000, the integrated tug and barge units have been chartered to Shell Oil Company for a period of 10 years with an option to extend for 25 years. They will serve ports along the Eastern Seaboard principally.

The pilots who maneuvered her into Port Everglades on the afternoon of March 6 reported the Catug units handled smoothly. A bow thruster was used for docking.

On her maiden voyage into the Port the units reached a maximum speed of 19 knots coming around the Florida Keys. This speed over the bottom was obtained with the help of the Gulf Stream. However, the Catug’s normal cruising speed is 14 knots.


The Catug barge segment is rated at 42,009 dwt, adequate to transport more than 5.6 million gallons of gasoline per voyage. Someone computed that this amount of gasoline would fill the tanks of 375,000 automobiles.

Welcoming the Catug were Seabulk Corp. President Hans Hvide (center); Eric Hvide (left) and Port Authority Chairman Fred Stevens (right). (Photo: American Shipper)

The Catug differs from other integrated tug and barge systems in that the tug is designed with a catamaran type hull and locks onto the barge with a tongue-and-groove fit, which gives the outward appearance of a single hull and assures maximum strength.

The concept was developed by officials of Seabulk Corporation at Port Everglades in conjunction with J. B. Hargrave Naval Architects, Inc., of West Palm Beach. Both sections of the first Catug units were built at Kelso Shipbuilding in Galveston, Texas.

On hand to welcome Seabulk Challenger and its barge to Port Everglades after the maiden voyage were Hans J. Hvide, president, and J. Eric Hvide, vice president of Seabulk
Corporation, and Fred J. Stevens, chairman of the Port Everglades Authority.

“The 42,009-ton Catug combines a catamaran tug and tongued barge through a patented, solid but quickly-separable connection system that allows great maneuverability,” Eric Hvide said. “It maintains the dependability, efficiency and performance of regular ships and the inherent advantages and economies of tug and barge operations.”

“Its benefits include reduced construction and operating costs, high propulsion efficiency, increased cargo capacity, and better crew safety and environment,” he added.

FreightWaves Classics articles look at various aspects of the transportation industry’s history. Click here to subscribe to our newsletter!

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