Unquestionably, the watershed event in the evolution of oil spill prevention and response technologies used by Alyeska Pipeline Service Co. was the Exxon Valdez oil spill.
In a little over 11 1/2 years, oil tankers had taken on loads of Alaska North Slope crude and transported them to market without incident nearly 9,000 times.
But on March 24, 1989, all that changed when the Exxon Valdez ran aground on Bligh Reef. An inexperienced crewman, maneuvering to avoid huge chunks of ice that had calved into the Sound from Columbia Glacier, managed to rip a hole in the bottom of the single-hull tanker.
The resulting oil spill disaster grabbed headlines around the world and brought years of outrage and recriminations. But a significant outcome of the entire episode was an aggressive move by Alyeska, in cooperation with the U.S. Coast Guard, the State of Alaska and others, to ensure that nothing like the Exxon Valdez spill could ever happen again.
Part of that response was the creation of the Ship Escort Response Vessels System or SERVS, as it is commonly known. Established July 10, 1989, SERVS soon acquired a fleet of tugboats and escort ships and set up a schedule for the vessels to escort oil-laden tankers through Prince William Sound into the Gulf of Alaska.
Their mission: Help steer the oil tankers out of harm’s way and provide initial oil spill response in an emergency.
“Some of the boats could do docking, and some were equipped more for towing operations and used for escorting the tankers through the sound,” said Greg Jones, senior vice president of operations at Alyeska. “We had another class of vessel that pretty much had a bunch of pollution response equipment on board and did provide a lot of value as a tug.”
Crowley’s tugs world-classAlyeska hired Crowley Maritime Corp in 1995 as its long-term marine contractor to provide tugs, barges, and qualified personnel for SERVS. The goal was to comply with federal and state regulations imposed as a reaction to the Exxon Valdez spill, according to Chairman, President and CEO Thomas B. Crowley Jr.
But an objective assessment of SERVS revealed the system’s inefficiencies and that it lacked the prevention focus that Alyeska adopted as its top priority, Jones said.
To improve SERVS capabilities, Alyeska and Crowley designed and built two classes of new tugboats with an emphasis on prevention and with input from state, federal and industry experts as well as local citizens on the Prince William Sound’s Regional Citizens’ Advisory Council.
Alyeska rarely departs from its traditional approach of purchasing off-the-shelf technology but in this instance, the company opted to build the tugs from scratch. In developing the final designs for the tugs, the company spent $2 million on a risk assessment study in which the State of Alaska, the marine shippers and the council collaborated.
“We wanted to build the system based on science and good engineering practices and not just on people’s hunches,” Jones said.
“We have developed and built vessels to meet the “Best Available Technology” requirement of the State of Alaska and Alyeska, both of which are committed to making Prince William Sound safe for oil transportation,” Crowley told Time Magazine in 2001.
Crowley has supplied SERVS with three prevention-response tugs or PRTs and two enhanced tractor tugs. The PRTs can generate a certified bollard pull of 305,000 pounds and a free running speed in excess of 16 knots. They also are equipped with firefighting cannons and emergency response and oil spill recovery equipment. The enhanced tractor tugs are the most powerful cycloidal propulsion tugs ever built, capable of moving 360-degrees in either direction, a bollard pull of 208,000 pounds and a vessel speed of 14.5 knots.
“The specially designed tractor tugs are amazing,” said Jones. “They have a deep skag or keel that enables them to turn sideways in the water without capsizing. This creates a tremendous drag, or braking force to stop a tanker.”
If a conventional tug tried the maneuver, Jones said, the forces involved would flip the vessel over.
PRTs can turn 360 degreesJones said the PRTs have “z” drives and rotating dual thrusters on their sterns. “Think of them as having conventional propellers but ones that can turn on their axis 360 degrees,” he said. “Those tugs are more capable as towing vessels in open water because they have the brute strength to come alongside a tanker and take it into tow, if necessary.”
All five tugs have 10,000 horsepower engines, and together, they cost $75 million. They also are equipped with state-of-the-art water cannons to combat a possible fire on a tanker or at the Valdez Marine Terminal.
“There is nothing like them in the world,” Jones said. “My understanding is we have more firefighting capability in Prince William Sound than they have on the entire (Lower 48) West Coast.”
In addition to the extraordinary tugs, SERVS maintains several conventional tugs, a supply boat, and an oil spill response vessel as well as six large barges, four of them manned, and an assortment of skimmers and small barges for response readiness, all of which is based on the latest and best technology available, officials say.
Jones said the U.S. Coast Guard also operates a vessel traffic service where it monitors all vessels in the sound and joined Alyeska, the state, marine shippers and others in installing ice detection radar that tracks movement of ice coming from Columbia Glacier that would pose a hazard to oil tankers.
If a chunk of ice drifts too close, the Coast Guard informs the affected tanker of its location. “It’s just one more piece of data that can be transmitted to the captain of a tanker to help the vessel make a safe transit,” Jones said.
Alyeska’s focus on prevention and the updated technology got a real life test in 2001 when the Chevron Mississippi oil tanker traveling through the Valdez Narrows avoided a collision with a fishing vessel that strayed into its path.
“These tugs stopped the tanker very abruptly, and nothing else happened,” Jones said.