Alyeska: tug concerns a result of incomplete information
Alyeska Pipeline Service Co. remains confident in the ability of the incoming fleet of oil tanker escort tugs to continue safe operations out of the Valdez marine terminal in spite of vessel design concerns raised by a third-party naval architect.
Alyeska spokeswoman Michelle Egan said many of the potential performance shortcomings identified by marine engineer Robert Allan were due to a simple lack of timely and detailed information about the tug designs.
“The construction of new vessels represents a significant improvement for the (Prince William Sound) oil spill prevention and response system,” Egan said in an interview.
Allan is chairman of the Vancouver-based naval architecture and marine engineering firm Robert Allan Ltd., which was founded by his grandfather and carries the family name.
He highlighted a litany of perceived flaws in the designs and performance modeling for the new Valdez-bound escort and support tugs being built by Edison Chouest Offshore in a Jan. 19 presentation to the Prince William Sound Regional Citizens’ Advisory Council.
The issues Allan raised related to everything from galley configurations to inclusion of cold-weather operating equipment to fundamental design characteristics such as bow shape and skeg size.
Allan recognized repeatedly during his presentation that he did not have access to all of the technical design documents for the tugs, as well as the fact that his firm is a competitor to Damen Shipyards Group, the Dutch company that designed the vessels under construction at Edison’s Gulf Coast yards.
The new tugs, scheduled to go into service in July 2018, include five, 140-foot escort tugs and four, 102-foot support and docking tugs.
Last June, Louisiana-based Edison Chouest Offshore announced it had won the 10-year contract from Alyeska Pipeline Service Co. for the Prince William Sound ship escort and response vessel system, or SERVS.
Edison Chouest will take over for longtime SERVS operator, Florida-based Crowley Maritime Corp.
The Prince William Sound citizens’ council commissioned Allan’s study of the tug designs.
A press release from the council notes the new tugs will replace some vessels in excess of 40 years old that are currently operating out of Valdez and will be outfitted with the new infrared and ice-detecting radar systems along with new oil detecting equipment should a spill occur.
“While the council is encouraged by some of the improvements that will come with this transition, our review has reveals some areas of concern that the council is bringing to the attention of Alyeska, so they can be addressed before construction is complete,” council Executive Director Donna Schantz said.
Edison Chouest referred questions on the matter to Alyeska.
A number of design elements have changed since the documents Allan was provided were published, Egan said, noting members of the council meet regularly to discuss the SERVS transition.
Many of Allan’s calls for cold weather equipment or related design contingencies were addressed even before his draft report and presentation to the council, according to Egan.
“(Allan) was looking at some very preliminary information,” she said.
For example, steps to protect winches and stored mooring lines have been incorporated into the tug designs as have deck heating and changes to the deck freeing ports to prevent foredeck pooling — a primary concern of Allan’s — Egan described.
The information provided to Robert Allan Ltd. through Alyeska and the council was what was available as of Dec. 14, according to a council release.
She added that the tugs will be outfitted with render-recover winches that automatically release or spool lines to maintain constant towing tension at the request of the council.
Egan also noted that as a competitor to Damen there is significant proprietary design information that was not accessible to Allan’s firm and that there are almost inevitably going to be areas of professional disagreement.
“We are confident that these vessels are a significant improvement over the current fleet and that they’ll meet the needs of the mission in Prince William Sound,” Egan said. “They’re built for purpose and they will have to demonstrate that to the United States Coast Guard, to us and to (the Alaska Department of Environmental Conservation), not just before they’re going to be put into service but repeatedly through exercises and drills.”
Those operability tests will start even before the tugs arrive in Alaska, she added.
Elwood Brehmer can be reached at [email protected].