Escort tugs need evaluation, council says

Are the tugs used to escort oil tankers in Alaska’s Prince William Sound really up to the job?

The Prince William Sound Regional Citizens’ Advisory Council is raising the question.

The council is calling for tests to make sure the tugs are “sufficiently powerful and stable.”

And the group suggests it’s time to “plan for the possible future phase-in of tugs that meet higher standards.”

The purpose-built tugs operating in support of tankers calling on Valdez to pick up North Slope crude “are now at least 12 years old, and no longer represent state-of-the-art technologies,” the council said in a March 23 submission to the Alaska Department of Environmental Conservation.

The council said it recently funded a study to compare Prince William Sound tugs against other vessels. The group also reviewed a proposed escort vessel system for the oil terminal Enbridge Inc. is pursuing at Kitimat, British Columbia.

Prince William Sound tugs “would not meet the specifications” for the Kitimat terminal, the council said.

Alyeska Pipeline Service Co., which operates the tanker terminal at Valdez, contracts with Crowley Maritime Corp. for a fleet of tugs to escort oil tankers.

Two tugs accompany each oil-laden tanker through Prince William Sound, with one tug typically tethered to the stern of the tanker. These tugs can stop or control the tanker in the event of trouble.

The council, in an April 6 letter to Alyeska, recommended “full-scale bollard pull and steering pull tests,” among other steps, to make sure Prince William Sound tugs are fit for escort duty.

In particular, the council said, the tugs should be rated for “indirect towing,” whereby the tug can actually turn sideways to brake or control a tanker.

The council also recommended upgrades to towline winches aboard the tugs.

The recommendations are based on a council-commissioned analysis from Det Norske Veritas, a Norwegian concern specializing in risk management.

—Wesley Loy