The Observer, May 2006
Nikiski grounding proves two hulls better than one
A tanker design improvement mandated after the Exxon Valdez oil spill demonstrated its worth early this year in Cook Inlet.
Just before dawn on Feb. 2, heavy, tide-driven ice floes pushed the tanker Seabulk Pride away from the loading dock at Tesoro’s Nikiski refinery and drove it onto a nearby beach. The vessel went through two full tidal cycles before being refloated and pulled clear about 24 hours later.
Despite the impact and the long night on the beach, none of the 116,000 barrels of refined products on board leaked out during the grounding.
TWO HULLS – The Tesoro tanker Seabulk Pride grounded on a Cook Inlet beach near Nikiski early on the morning of Feb. 2. It was pulled off the next morning, without leaking any oil through its double hull. The incident has triggered fresh calls for tugs to assist with oil operations in Cook Inlet. Photo by Tim Robertson.
Those involved in responding to the incident credit that to the fact that the Seabulk Pride has a double hull, as required by the federal Oil Pollution Act of 1990. The act, passed in response to the 1989 Exxon spill, bans single-hull tankers from U.S. waters after 2015. They are already being phased out, and, today, nearly all tankers in Alaska waters have double hulls.
A double-hull tanker has two hulls separated by several feet of space. Only the outer hull is in contact with the sea, and only the inner hull is in contact with the toxic cargo. If such a tanker goes aground and the outer hull is penetrated, the buffer of empty space means that, in most cases, the inner hull is untouched and no oil is spilled.
The Seabulk Pride did sustain some small cracks in its outer hull while on the Nikiski beach, but the inner hull remained intact. An official at the American Bureau of Shipping said the cracks probably would have produced at least some seepage of crude oil if the vessel had had a single hull.
The incident prompted the Coast Guard to stiffen the rules for vessels operating in and out of Nikiski during winter conditions combining heavy ice and fast tidal currents.
It also triggered renewed calls for tugs in Cook Inlet by the citizens’ councils for Cook Inlet and Prince William Sound, among others. Though a comprehensive escort system was established in Prince William Sound after the Exxon spill, Cook Inlet is still without tugs, despite repeated calls for them over the years.
After the Seabulk Pride was refloated, it was taken to Kachemak Bay for inspection and temporary repairs before being moved to the West Coast for permanent repairs. That has raised concerns in Homer, where the city council held a panel discussion on the subject in early April.
“Apparently, we are now designated as a port of refuge,” James Hornaday, Homer mayor, told the press. “The idea is to try and find out what that means.”