NOAA program identifying sunken vessels that pose environmental threats
The National Oceanic and Atmospheric Administration is undertaking a comprehensive effort to identify the sunken vessels along the U.S. coast that represent the most serious threats to the environment.
|A fishing net hangs over the superstructure of the tanker Montebello, which sank during World War II near California’s Monterey Bay. Its 3 million gallon cargo of heavy oil may still be in the wreck. (Photo courtesy NOAA/Robert Schwemmer)|
Called Resources and UnderSea Threats (RUST), the program is targeting World War II-era ships that may pose significant pollution threats from oil or other hazardous materials escaping from the deteriorating vessels.
A series of serious incidents of oil coming ashore south of San Francisco in the early 1990s led to major wildlife disasters between 1997 and 2002 in NOAA’s Gulf of Farallones National Maritime Sanctuary. The oil killed 51,000 sea birds, eight sea otters and fouled 40,000 square miles of shore tidal flats. The search for the source of the oil using divers and oil fingerprinting technology finally established it as the 468-foot SS Jacob Luckenbach, The cargo ship, launched in 1944, sank in 175-foot deep water in 1953 after a collision 17 miles off San Francisco.
As the Luckenbach wreck gradually deteriorated, oil seeped out of the ship. A report by the Monterey Bay National Marine Sanctuary concluded a large 2001-2002 discharge probably occurred when the ship was rocked on the sea floor by swells during strong storms.
“The winter storms would tip the Luckenbach in a way that she would burp up some oil. Then we would not hear from her again for nine months,” said Michael Overfield, a marine archaeologist with the NOAA National Marine Sanctuary program.
Titan Maritime was awarded a contract in 2002 to assess the Luckenbach wreck. Titan teamed with Crowley Maritime, PCCI and Global Diving and Salvage to remove all recoverable oil from the ship, which was lying in three sections.
The salvors used saturation dive runs of four two-man teams and a variety of high-tech systems, including multibeam technologies to map the ship, sub-sea oil heating systems and a remotely operated underwater vehicle. Removing oil from the wreck was a complex challenge for the salvors. The oil, which had solidified over the years, had to be slowly liquefied by heating before it could be removed.
Estimated at $8 million originally, the project ended up costing almost $19 million, in part because of delays from storms with 16-foot seas and 45 knot winds. When the project was completed after five months, three months longer than expected, almost 100,000 gallons of heavy bunker C oil had been recovered.
|Montebello?s anemone-covered prop. (Photo courtesy NOAA/Robert Schwemmer)|
The Luckenbach operation raised important concerns. “NOAA’s Office of Marine Sanctuaries was concerned with other threats immediately within the sanctuaries and up to 125 miles outside,” Overfield said. “How many more ships like the Luckenbach were out there and how could we best get a handle on it?”
RUST emerged in 2003 as the answer to those concerns. With the help of RUST, “the agency could look at potential threats proactively, instead of responding reactively,” Overfield said.
The structure of RUST’s database was completed in 2003, and in 2004 information entry began using marine casualty data collected from various federal, state and private sources.
RUST remains in the developmental stage, but currently has over 300,000 vessel records, according to Overfield.
Researching the records may be tedious, but Overfield observed, “We don’t want to lose any information important to our database.”
That includes vessel names, cargoes, how the vessels were lost and their reported location at the time of sinking. Overfield said a set of parameters has been established to evaluate how much oil may still be on board any vessel based on the events of the sinking.
As a result, the RUST program has identified over 7,000 sunken ships, mainly in U.S. waters; 1,122 of them over 100 tons contain an estimated 1.3 billion gallons of oil.
The structural condition of a wreck will be one important factor in determining its priority for remediation. The 440-foot tanker Montebello was torpedoed and sunk off Cambria, Calif., in December 1941 with a 3 million gallon cargo of heavy oil. The wreck is in 850 feet of water close to the southern edge of the Monterey Bay National Marine Sanctuary. Previous explorations between 1996 and 2003 with a submersible found the wreck’s hull to be upright and apparently intact except where the bow separated when the torpedo hit. There is no evidence of oil leakage, so the entire cargo may still be in the wreck’s tanks.
The 6,778 gross ton tanker Coimbra lying in the Atlantic Ocean 20 miles off Long Island, N.Y., is a more serious environmental risk. After the ship was torpedoed in 1942, the cargo of lubricating oil was believed to have been released and burned before the ship sank in 180 feet of water. But some oil has steadily leaked from the hull that is broken into three parts and lying on its side, and the spills have required several beach cleanups.
The research phase continues to add ships to the RUST database. Assessments will be undertaken using this data to determine which vessels present the largest environmental threat and potential shoreline impacts. “Then we could go out and do an assessment of those now leaking. We have recently been talking with the U.S. Coast Guard about setting up a pilot project to assess some of the vessels,” Overfield said.
“Steel does deteriorate as time goes on,” noted John A. Witte Jr., president of the American Salvage Association. “What we at the ASA don’t want to see happen with any of the sunken vessels that NOAA has identified as part of their RUST program is an oil discharge due to failure of the hull, resulting in significant pollution. It is cheaper to try to remediate it in place than wait for it to break open and leak oils. While it’s easier to clean it up once oil is outside the ship, it is also a lot more expensive. The U.S. Coast Guard is involved in evaluation of this program, because it’s cheaper in the long run if appropriate targets are identified.”
He suggested that “a group effort between the government and private business” could be part of the solution.
RUST’s vessel assessments can help determine the condition and stability of wrecks to aid salvors before undersea work begins to avoid any accidental releases from structural failures, said Overfield. Years under water results in corrosion of rivets and welds. Combined with hogging, the corrosion causes a vessel’s structure to weaken. Those unseen changes can open seams of tanks, allowing oil to escape.
SS Palo Alto is an example of vessel structural changes occurring within view, yet causing unexpected environmental damage. The tanker was built in 1919 as part of a World War I shipbuilding program using cement instead of steel for the hull and superstructure, but steel for the oil tanks. Once retired, the ship was beached at Seacliff State Beach in Aptos, Calif., in 1930 as a tourist attraction. Later it was used as a breakwater, and then beoame part of the fishing pier, where it remains.
In 2004, oil covered sea birds were found around Seacliff. The investigation using oil fingerprinting determined the wildlife had all been exposed to the same oil source. The investigation ruled out passing ships discharging oily bilge water and sunken ships offshore. In 2005, attention turned to SS Palo Alto and oil was found in its steel tanks that after almost 80 years had begun to leak. The salvage contract to eliminate the pollution source was awarded in 2006 to Titan Salvage.
The RUST project was initially undertaken by NOAA’s National Marine Sanctuary program to help protect its marine sanctuaries from oil spills. The program’s goal is now to include detailed information and wreck assessments for all U.S. coastal waters and significant inland waterways. As proven by the SS Palo Alto incident, even a benign-appearing hulk can unexpectedly pose a major environmental risk. The growing RUST database will provide private and public benefit along U.S. shorelines and could become an increasingly vital planning tool for salvors.