The remaining oil was transferred from the tanker to lightering barges.
The incident occurred around 2115 as the 750-foot Athos I approached the Citgo asphalt refinery in West Deptford, N.J., with a cargo of 325,000 barrels, or nearly 14 million gallons, of heavy Venezuelan crude oil.
Crewmembers aboard two assisting tugboats noticed an oil slick coming from the tanker. At about the same time, Athos I developed an 8Â° list to port and lost power. The crew quickly located the leak and transferred the oil to other tanks to avoid further spillage.
The following day, divers found a 6-foot gash in the No. 7 center cargo tank and the No. 7 ballast tank. Another underwater inspection on Nov. 28 revealed a smaller puncture near the larger gash.
Initially, 30,000 gallons was thought to have leaked from the tanker. That estimate was raised to 473,500 gallons on Nov. 30 by Capt. Jonathan Sarubbi, the U.S. Coast Guard captain of the Port of Philadelphia.
It was unclear if the missing oil spilled into the river or flowed into other spaces on the ship, such as ballast tanks. If the oil did end up in the river, the loss would surpass the record for the Delaware of 300,000 gallons spilled by a tanker that ran aground near Claymont, Del., in 1989.
After entering Delaware Bay on the afternoon of Nov. 26, Athos I paused briefly off Cape Henlopen, Del., to take on a pilot from the Pilots’ Association for the Bay and River Delaware, and two security guards from the U.S. Coast Guard. The 21-year-old single-hull tanker rode the tide up the Delaware, drawing 36.5 feet in the 40-foot-deep ship channel. At about 2100, after passing beneath the Commodore Barry Bridge and with a docking pilot aboard, Athos I made a 90Â° turn to starboard to approach the Citgo dock.
There is no evidence at this stage of the investigation to indicate any piloting or navigation errors, the Coast Guard said.
Four days after the accident, the slick from Athos I covered a 44-mile stretch of the Delaware from the Tacony-Palmyra Bridge that links Burlington County, N.J., and northeast Philadelphia to the Salem, N.J., nuclear power plant on Artificial Island about five miles downstream from the Delaware Memorial Bridge.
The power plant was shut down for several days after the spill, when the slick came dangerously close to its cooling-water intakes. Oil containment booms were placed around the intakes, and the power plant was not damaged, according to the Public Service Electric & Gas Co., the plant’s operator.
The concentration of spilled oil was heaviest along the 10-mile stretch of the river between the southern end of Little Tinicum Island off Essington, Penn., and the Schuylkill River, which enters the Delaware at Philadelphia.
The heavily industrialized Port of Philadelphia was closed for three days while salvage teams and environmental cleanup workers descended on Athos I. Nearly 50 ships, primarily tankers and bulk carriers, were held either at their riverside berths or at the Big Stone Beach anchorage in Delaware Bay.
The port was partially reopened on Nov. 30, significantly easing congestion that was rapidly building up and down the Delaware. Twelve ships entered the port and three departed when the Coast Guard gave them the green light. An additional 23 were waiting to depart, and another 25 were either in Delaware Bay or at sea waiting to come upriver, according to the Coast Guard.
The ship’s owners, Tsakos Shipping and Trading SA, quickly assumed responsibility for the spill and said it occurred as the ship struck a submerged object while moving slowly toward its berth.
Initially, speculation about what Athos I might have struck ran the gamut from spikes planted in the river bottom to impale British warships during the Revolutionary War, to lost equipment or sunken vessels that have accumulated on the bottom over the centuries. Then on Dec. 7, divers found the 15-foot-long curved pipe.
The pipe was located by sonar in the anchorage about 700 feet from the Citgo dock. Preliminary tests of paint scrapings from the pipe and Athos I showed a positive match. Athos I’s GPS track indicated that the tanker had passed over the pipe as it approached the dock.
The pipe was recovered for further testing, the Coast Guard said.
Before the discovery of the pipe, attention had focused on a 14-foot-diameter propeller and section of propeller shaft that were lost from the U.S. Army Corps of Engineers dredge McFarland on April 23, 2004. McFarland lost the propeller and shaft near the spot where Athos I is believed to have struck an underwater object. The channel was closed for three days, but sonar surveys failed to find any trace of the propeller.
Still unknown is just how much oil was recovered either from the river or the shoreline, how much is floating below the surface and how much is lying on the bottom, like a huge asphalt cap.
To prevent oil-stained hulls from possibly spreading the heavy crude oil throughout the river, outgoing ships were required to have their waterlines cleaned with high-pressure steam. The decontamination process was made discretionary after the first few days, the Coast Guard said.
The day after the port captain reopened the river, he imposed a new restriction, presumably to last until the lost-propeller question is resolved. Under the new decree, vessels drawing more than 34 feet can operate in the 40-foot-deep channel only at high tide.