High Damage Rate : Alaska Oil Ships in Sea of Troubles

In October, 1987, the American supertanker Stuyvesant was battling heavy seas and gale-force winds in the Gulf of Alaska, its tanks filled with North Slope crude oil loaded in Valdez, when the pounding waves fractured its hull. More than 600,000 gallons of oil oozed from the wound.

It was the second time in 10 months that the 1,100-foot Stuyvesant had been cracked open by the sea. In the previous January, the tanker had sailed through several days of bad weather before anyone noticed the leak. By that time, another 600,000 gallons had spilled into the North Pacific.

But the alarming truth is that the Stuyvesant was no isolated case. The Coast Guard recently placed Alaska tankers on a special inspection watch after its own survey discovered that oil tankers sailing the storm-prone Gulf of Alaska suffer more than three times as many hull cracks and other structural failures as tankers on other trade routes.

Some of the Worst

And a Times analysis of more than 60 ships serving the Trans-Alaska Pipeline terminal in Valdez, a study done in the aftermath of the Exxon Valdez disaster in Prince William Sound, has discovered that the Alaska tanker fleet is an aging and weather-battered fleet that includes some of the worst oil tankers flying the American flag.

Detailed histories of the Alaska tankers, compiled from public and private records, show that they are some of the world’s oldest ships and that many have troubled histories of accidents and oil spills around the world.

More than a dozen ships, representing more than 20% of the Alaska fleet, are regarded as high- risk tankers for would-be charterers, according to an industry rating service. More than a third of those tankers received poor to marginal ratings by the New York-based Tanker Advisory Center in its 1989 Guide for the Selection of Tankships.

Ships Not Wanted

“Those are the ships you want your competitors to charter,” said Arthur McKenzie, director of the center and author of the rating guide.

Not all of the poorly rated ships are old. For example, the problem-plagued tankers Bay Ridge (11 years old) and Stuyvesant (12), both operated by Seatrain Lines, are rated high risks for charterers. Both ships have suffered multiple hull and deck damage from bad weather.

What the two ships have in common is their extraordinary length: both are 1,100 feet long, a factor the Coast Guard believes contributes substantially to the rate of tanker hull failures throughout the Alaska fleet.

The American Bureau of Shipping, a maritime industry agency that enforces design, construction and maintenance standards on U.S.-flag ships, will convene a private two-day conference of ship owners and technical experts in New Jersey later this month to investigate whether new construction and operations standards need to be developed for Alaska tankers generally or for specific sizes and classes of ships.

Tom Tucker, vice president of the ABS, said the Coast Guard study and independent observations by ABS surveyors, suggest that severe weather is making tankers age faster along the Valdez trading route and presents particular problems for long ships.

“Weather is one of the factors, like salt water, that ages steel. It looks like ships in the Alaska trade are experiencing more stresses,” Tucker said.

The Alaska fleet is getting old even without the weather beating. About 60% of the fleet was built at least 15 years ago. And the average age of the fleet is increasing as few new commercial tankers are built.

Lloyds of London insurance statistics show that tankers over 10 years old have casualties (accidents, structural failures or significant mechanical breakdowns) 60% more often, on average, than newer tankers.

Some of the oldest ships on the Alaska route have been the three-ship Cove Shipping Co. fleet. All are older than 30 years and are ranked as chartering risks by the Tanker Advisory Center. Richard Maybruck, a chartering official for Cove in New York, challenged the rating and said the firm’s ships are well maintained.

Guarantee Cleanup Costs

“I have no idea why we got a low rating,” he said. Maybruck said Cove’s ships are insured to $300 million and chartered to major oil companies such as Exxon, Arco and BP America who also guarantee pollution cleanup costs in the event of an accident.

Earlier this year the Cove Leader, an 810-foot tanker built in 1959, spilled about 2,500 gallons of oil into the Port of Valdez before anyone noticed a hull crack below the waterline believed caused by a bump from a tugboat. Pollution cleanup cost $1 million.

Two old ships in the Texaco fleet--the Texaco Connecticut (built in 1953) and the Texaco Florida (1956)--also make regular calls at Valdez. The Tanker Advisory Center rated the second ship a “good” risk but regards the oldest ship a high risk for charterers.

In 1980, the Texaco Connecticut suffered a 24-foot gash when it ran over rocks in shallow waters of Panama and spilled 230,000 gallons of Alaska crude oil that polluted Gatun Lake and Cristobal Bay. It has since, in a series of separate incidents, run aground in the Mississippi River, lost its steering controls at sea, lost its propeller off Panama, had its engine room flooded in Puget Sound and suffered a collision with a freighter near Houston.

Maritime insurance experts expect the average economic life of an oil tanker to be no more than 20 years. In the oil boom years of the 1970s even ships over 10 years old were often scrapped and replaced with bigger, more efficient tankers.

Decline of the international oil market, however, has put a virtual stop to new tanker construction. The total number of tankers on the world’s seas has declined from more than 4,000 in 1976 to about 3,200 today--only about 200 of them are commercial American tankers.

With limited exceptions, only American tankers built in American shipyards and manned by American merchant marine crews can carry Alaska oil to U.S. ports, under terms of a federal law called the Jones Act.

No New U.S. Ships

Today, no commercial tankers are being built in any American shipyard, indicating that existing U.S. tankers will probably be working well beyond 20 years. Ironically, one of the last two American-flag tankers to slide off the building ways was the Exxon Valdez.

“Age isn’t good for any of us,” said the Tanker Advisory Center’s McKenzie, a former Exxon captain who conducts tanker operations seminars around the country for industry and government clients. He and other experts say age can only aggravate future problems in the Alaska shipping lanes caused by weather-related hull damage.

Rep. George Miller (D-Martinez), whose House Interior subcommittee just completed oil spill hearings in Valdez, told The Times he is “concerned about the status of the (Alaska) fleet,” and said that the industry promised to use only its best ships in Valdez. “If that is not the case, then the industry lied,” he said.

Miller also said that the federal government should consider setting a mandatory retirement age for tankers allowed to serve the Valdez terminal.

A spokesman for Cove Shipping defended the use of older ships, saying that most of them were built with stronger steel than modern tankers and therefore experience fewer cracking problems from harsh weather.

The Coast Guard, in fact, found that newer ships actually experienced most of the hull cracks. Rather than crediting stronger steel, however, the report attributed the finding to the fact that ships built more than 20 years ago were shorter. According to the Coast Guard, most of the hull failures occur to ships more than 700 feet long.

Ships Suffer Cracks

The 875-foot Thompson Pass, for example, was only 11 years old last January when 70,000 gallons of oil seeped out of what divers discovered was an underwater hull crack during loading in Valdez. And the 1,100-foot Stuyvesant was only 10 years old in 1987 when it twice lost 600,000 gallons through hull cracks discovered during stormy voyages.

Hull cracks usually occurred, the Coast Guard found, near the midships--in the middle 20% of the vessel. Within that range, the cracks were pretty evenly distributed over the ships’ decks, sides and bottoms.

The Coast Guard’s Marine Structural Casualty Study, which looked at ship inspection records and incidents reported from 1984 to 1986, blamed most of the failures on metal fatigue brought on by the constant bending of the giant ships under wave and swell pressures.

Failure occurs to the heavy steel hull plates in much the same way that it might occur to a wire hanger that is bent back and forth over a period of time until it weakens and then breaks.

The massive ships, the biggest on the Alaska route capable of carrying up to 230,000 tons of oil, bend and twist as waves lift them from the bottom and smash over their decks from one side or another. And in a ship the size of the Exxon Valdez, for example, one ton of hull steel supports about six tons of oil cargo that can slosh around and cause internal stress as well. Most of the stress from the constant bending action, however, is amidships.

“This suggests that considerable improvement could be made in the fatigue design of ship structures,” the report said, an issue almost certain to be raised in meetings called by the American Bureau of Shipping later this month.

Experience Most Failures

The most striking discovery of the survey was the high rate of fatigue cracking occurring to the Alaska tankers, as compared to freighters and to the rest of the U.S. tanker fleet. In fact, while tankers on the Alaska route represented only 13% of the ships analyzed by the Coast Guard, they accounted for more than 52% of the structural failures in the 3-year period of the survey.

And while seasonal stormy weather along some routes tended to coincide with incidents of structural damage to ships, the Alaska route showed little seasonal variation.

“This illustrates that while the summer months may be gentle in most trades, the whole year is harsh in the (Alaska) trade,” the Coast Guard report concluded.

Industry executives acknowledge some concern about the effect of bad weather and tanker aging on the future reliability and safety of the Alaska fleet, but contend that proper maintenance is the solution. However, an executive for a major New York shipping firm who declined to be identified said that continuing economic difficulties in the oil industry may prompt some marginal companies to skimp on ship maintenance.

“If ships are properly maintained, then there is no reason to fear,” said the executive. “But in the current economic climate the return is not sufficient to cover costs of maintenance, especially for (more costly) American tankers.

“In the end, we must make the investment in maintainance even if we make no profit--to protect our reputations.”

Demand Acute

The demand on tanker captains to keep their ships moving is particularly acute in the Alaska trade, where the pipeline pours 84 million gallons of crude oil into the terminal every day. An average of 2.5 tanker loadings each day are necessary, regardless of the weather, to keep the pipeline from backing up.

Crude oil supply shortages and gasoline price hikes that resulted, particularly on the West Coast, when the port was closed after the Exxon Valdez accident underscore the national reliance on that supply.

“Obviously, safety and environment have taken a back seat to those kinds of demands,” said a House Interior Committee aide.

Freighters operating in the same region do not appear to be so harshly affected. Nearly 70% of all the structural failures examined by the Coast Guard occurred to oil tankers, and all the ships with multiple failures were tankers.

Ships owned by Exxon and Keystone Shipping Co. reported six casualties each, the most by any other single operator. One ship, the Exxon Houston, suffered three hull failures during the 1984-86 period, the most by any single tanker.

In each case the rough Alaska transit was considered only part of the cause. Twice heavy seas caused oil to slosh violently inside the tanks, beating a hole in the hull from the inside out because the tanks were not properly loaded, according to the Coast Guard. The third failure was partially attributed to corrosion and metal fatigue.

The Exxon Houston has since been involved in more trouble. Last March it broke from its moorings while unloading crude in Hawaii, ran aground and spilled more than 30,000 gallons into the waters off Honolulu.

Companies Differ

The Times survey found that just as there are differences in individual ships, there are notable differences between the companies that operate them.

“In a sense, we’re lucky it was an Exxon tanker that ran over those rocks (in Alaska),” said a House Interior Committee aide. “If that had been a ship from Moe and Larry’s fleet, I wonder if the cleanup would have gone as well as it has.”

The major oil companies, most of which have tankers that also operate outside of Alaska, generally have the highest rated ships, according to the Tanker Advisory Center. McKenzie’s guide rates tankers on a scale of 1 to 5, with 5 being best. The Exxon Valdez was rated 5. Exxon, which operates 76 tankers worldwide, has a fleet average of 3.6.

Some of the rankings of other major tanker owners and operators serving Alaska are: Amerada Hess (fleet average: 1.9 for nine ships); Arco (3.1 for 10 ships); Chevron (3.5 for 42 ships); Keystone (1.5 for 15 ships); Overseas Shipholding (3.8 for 39 ships), and Union Oil (4.0 for 4 ships).

In addition to Amerada Hess and Keystone, other low to marginally ranked fleets with tankers serving Alaska include Cove Shipping (fleet average: 1.0 for three ships); Interocean Management (2.0 for four ships); Seatrain Lines (1.0 for two ships), and Trinidad Corp. (1.0 for three ships).

Fly Liberian Flag

Because of an exemption from the Jones Act for tankers serving refineries in the U.S. Virgin Islands, a handful of Alaska tankers fly the Liberian flag.

Some of those, such as the Eastern Lion and Northern Lion, are among the highest-rated tankers in the Alaska fleet. However, other foreign-flag tankers calling on Valdez are among the lowest-rated.

One of those is the 1,117-foot Mt. Cabrite--born the Sea Serpent in 1971. It is rated a poor risk for charterers because of its age and history. It has had multiple casualties involving weather damage, on-board fires and power failures.

On a voyage just last fall, for example, the Liberian-flag Mt. Cabrite was forced to put in for repairs in Chile after taking a beating from bad weather leaving Valdez bound for St. Croix. A few days after leaving a Valparaiso shipyard, still loaded with Alaska oil, the generator exploded and caught fire.

The tanker is operated by Amerada Hess. It has since resumed service to Alaska.

Its sister ship, the St. Lucia--also operated by Amerada Hess under the Liberian flag--is regarded similarly as a poor charter risk by the Tanker Advisory Center. Last year it too suffered hull damage from storms between Valdez and Cape Horn and, on a separate voyage, was forced to divert to Chile for repairs after a fire in the control room.

WHEN HEAVY METAL MEETS HEAVY SEAS

In the high seas frequently faced by Alaskan oil tankers, waves exert great pressure on the center of the long ships. As the swell rised, the ship droops both forward and aft. When the swell passes, the pressures reverse. The constant bending causes the center of the tankers, about 20% of the total length, to receive about two-thirds of all reported hull cracks.

The hull fractures take three forms, any one of which can lead to an oil spill.

1. Welds pop at seams of steel hull plates.

2. The plates themselves become brittle and crack.

3. The hull separates from the beam, creating a weakness that can lead to a leak.