Last updated: Tuesday 25 April 2000 NATIONAL NEWS

Work stops as menacing icebergs converge near oil rigs in the North Atlantic

MICHAEL MACDONALD

ST. JOHN'S, Nfld. (CP) - Water cannons mounted on supply ships are being used to blast icebergs drifting towards oil rigs on the Grand Banks.

Since last weekend, about a half dozen of the frozen hulks have been pushed or pulled away from the three rigs operating southeast of Newfoundland.

It's the first time in 10 years that icebergs - some of them the size of small apartment buildings - have threatened drilling operations.

"They tend to come in waves," Pip Rudkin, manager of iceberg tracking at Provincial Airlines in St. John's, said Tuesday.

About 50 bergs have been sighted within 100 kilometres of the oil fields.

As a safety measure, the two floating rigs - Glomar Grand Banks and Henry Goodrich - were shut down on the weekend. But it was business as usual at the 600,000-tonne Hibernia platform, which sits on the ocean floor and is engineered to withstand a direct hit.

"We deflected one yesterday to the west of the platform," said John Whalen, a radio operator and iceberg observer on the platform 315 kilometres southeast of St. John's.

"We used the water cannon."

Unfortunately, Whalen couldn't see the action because the Grand Banks also happens to be one of the foggiest places on the planet.

"We have zero visibility today," he said in an interview. "But we have radar so we're keeping a good eye on the area."

While drilling has resumed aboard the Henry Goodrich, operated by the Terra Nova oil consortium, the Glomar Grand Banks was on standby because a berg had run aground just four kilometres from the rig.

Persuading an iceberg to change course isn't easy. Towing can be tricky because bergs sometimes slip their lines by rolling over.

Water cannons offer the most dramatic display of brute force, but they only work on the smaller bergs, said Howard Pike, safety manager at the Canada-Newfoundland Offshore Petroleum Board.

A specially designed cannon on the bow of the Maersk Placentia, a supply ship based in St. John's, can muster enough pressure to move a medium-sized chunk weighing 60,000 tonnes.

"They start to disintegrate when they use that," said Pike. "The salt water melts them."

Another method, called prop washing, involves using the wake created by a ship's engines to push the berg in another direction.

Since March, about 12 icebergs have been towed while another half dozen or so have received the water cannon treatment.

Despite all the pushing and shoving on the high seas, this iceberg season is expected to be light in terms of overall numbers.

There are about 1,100 icebergs in the northwest Atlantic, but less than 200 are expected to make it south of the 48th parallel, said Rudkin.

"Once we get this lot cleared out we'll have a bit of breathing room," said Rudkin. "We expect another wave but it will be about the same size."

Those in Newfoundland's tourism industry are keenly aware that any number of icebergs would be better than last year's dismal showing.

Rudkin said about a dozen bergs have drifted south of St. John's since March. Residents on the province's north coast and around the Bonavista Peninsula are enjoying a great show.

Most icebergs are chunks of Greenland's constantly moving ice cap. Up to 30,000 enter the water each year, but only a few hundred survive the three-year journey to Newfoundland's coast.

Some resemble ice-blue cathedrals or ghostly sailing ships, but most are flat-topped slabs that leave only 10 per cent of their bulk exposed above the water.

Some commonly used guidelines for categorizing icebergs:

Large:More than 120 metres. As big as an oil rig.

Medium:60 to 120 metres. As big as an ocean-going ship.

Small:15 to 60 metres. As big as a fishing boat.

Bergy Bit:Five to 15 metres. Size of a bungalow.

Growler:Less than five metres. Size of a grand piano.

Age:The fresh water in an iceberg is at least 12,000 years old.

Source: Centre for Cold Ocean Research.

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-- Martin Thompson (mthom1927@aol.com), April 25, 2000

Answers

This reminds me of the big breakoff of that huge block of ice in Antarctica a few weeks back.

Don't bother to phone anybody down there. But, if you must, the area code is 672.

-- JackW (jpayne@webtv.net), April 25, 2000.