Britain's bow-less barge

Question. When is a fire engine a hotel? Or, when can a hospital go seven knots? Or when is a 350-ton mobile crane a heliport? Or when is a ship with no hull worth $96 million?

The answer: when it is the "MSV Tharos." "MSV" stands for "multifunction support vessel," the newest and most sophisticated addition to the offshore oil industry's flotilla in the North Sea.

Whatever you call it -- and the men here described it simply as a "barge" -- it is open season for riddlemakers, who generally begin their visits by asking, "Where is the bow?" The Tharos appears to have several. Two fully equipped computerized bridges look out in opposite directions, each of which makes the console of a "Star Wars" spaceship look like a simple stereo. After all, why turn around when you can go full speed astern?

But a ship it truly is -- though not in looks. Commissioned Feb. 7, it resembles nothing so much as a square table floating legs-down-ward on submerged pontoons and riding high above the shockingly blue North Sea waves.

A descendent of earlier semisubmersible oil-drilling rigs, it maintains an almost spooky stability -- about one degree of roll in a 55-knot wind with 35 -foot swells. The four 3,000 h.p. computer-controlled "thrusters" on each corner provide "dynamic positioning" -- ship talk for its ability to hover, unanchored, over a fixed position on the seabed without moving more than a few feet in any direction.

Riddlemakers next ask, "Why build it?" The attention-getting answer is the ship's firefighting capacity: water cannons that can throw 40,000 gallons of water a minute across 240 feet, and a huge boom-and-claw rig that can pull 20 tons of melted metal or debris away from a wellhead after a blowout.

Designed in collaboration with Houston's famous oil-well firefighter, Red Adair, this equipment can be moved into action against such disasters as the 1977 fire at the nearby Bravo oil field. Important to its firefighting effectiveness is the fact that it rides high in the water and provides a stable base for cannon-aimers.

But the Tharos doesn't need disasters to justify itself. The owners, Occidental North Sea Consortium (75 percent ownership) and BP (25 percent), hope to succeed by hiring out the more mundane services to other firms in the 100 -mile-square Yellow Sector.

"We've got to prove to people what we can dof or them," says Occidental marine supervisor Jack Skinner. He hopes to sell the offshore community on the ship's sophisticated deep-sea diving facilities (incuding an electric submarine and three decompression chambers), and on its machine shop, heavy-lifting capacity, 23-bed hospital, and accommodations for 150 men beside the crew.

Hans valdhuis, superintendent for the Dallas-based South East Drilling Company, which sold the ship and retains a five-year management contract, agrees. "You're bringing a lot of world together," he says -- a quiet understatement by a Dutchman in a community where Spanish catering workers rub shoulders with Scottish firefighters and US Navy diving consultants.

Even the ship itself, built by Mitsubishi of Japan to specifications of the San Francisco engineering firm of Earl & Wright, is a testametn to the world-class nature of today's offshore technology.

According to cost engineer Ray Currie, the ship will cost $21 million to operate this year. Anchored several dozen yards from the Pier platform, it houses 180 construction and maintenance men -- saving $30,000 a day over similar accommodations leased last year. That savings, with income from other services, should allow the Tharos to pay for itself in about five years.