|Eagle Tucson was carrying 602,000 barrels of crude oil when it grounded at the edge of a 750-foot-wide deep-draft channel. (Courtesy U.S. Coast Guard)|
The U.S. Coast Guard is investigating how an Aframax tanker full of crude oil strayed to the edge of the Lower Mississippi River’s deep-draft channel and ran aground near Pilottown, La.
Oceangoing traffic was disrupted for an entire day after the inbound Eagle Tucson grounded at 0245 on Sept. 28. The Singapore-flagged tanker contained 602,000 barrels of crude.
A Crescent River Port pilot was guiding the 810-foot ship at the time of the grounding, which occurred in clear weather. No mechanical failures were reported, the Coast Guard said.
An Army Corps of Engineers survey showed that Eagle Tucson grounded along the edge of the designated deep-draft channel on the vessel’s starboard side.
The tanker’s owner-operator, AET Shipmanagement of Singapore, said the area still should have provided sufficient depth.
“It is our view that Eagle Tucson was not outside the channel when she grounded. … This grounding was not caused by any malfunction of equipment or any misjudgment on the part of the pilot or the bridge team,” AET spokesman Paul Lovell said in mid-October.
In an earlier interview, Lovell said, “It looks as though there was silting in the channel potentially.”
|A Coast Guard response boat sails astern of the tanker. (Courtesy U.S. Coast Guard)|
The deep-draft channel is 750 feet wide in that area. Surveys before, during and after the grounding showed that the channel more than met its minimum stated depth of 45 feet, said Army Corps spokeswoman Dominique Rouzan. The depth was as much as 48 to 51 feet in the area, plus the river was 4.7 feet higher when Eagle Tucson transited.
“All the surveys show that we had full project dimensions (and) no obstructions,” Rouzan said.
The double-hulled tanker grounded in soft mud, at a spot where the depth rapidly declines from deep-draft standards to less than 40 feet.
AET said Eagle Tucson drew 44 feet 10 inches, during that transit. The pilot verified that the ship’s draft was within the maximum safe limit for the conditions, and the Coast Guard confirmed it, according to the company.
The vessel grounded just forward of midships, over a length of 50 to 60 feet. After the tanker got stuck, the crew conducted a sounding on the starboard side and received a depth reading of 43 feet, Lovell said. The clearance below the keel was 3.6 feet. As the tide was falling, the Coast Guard measured a 42-foot depth.
When Eagle Tucson grounded, the 30-foot hydraulic dredge R.S. Weeks was operating along the opposite edge of the channel — to the tanker’s port side. Coast Guard investigators would not say whether the ship had moved to starboard while passing the dredge.
The ship was headed to Chalmette, La., when it got stuck 85 miles downriver from New Orleans. The vessel was not damaged, and no oil spilled. Six tugboats attempted to refloat Eagle Tucson.
“Somehow they shifted the fuel from one side to another, and that helped that one side dislodge,” said Coast Guard spokeswoman Petty Officer Casey Ranel.
The river was closed for 13 hours, said Brett Bourgeois, executive director of the New Orleans Board of Trade. Thereafter, the Coast Guard allowed vessels with a draft of 35 feet or less to pass by. About eight ships were delayed until Eagle Tucson refloated at 0415 on Sept. 29.
Crescent River Port Pilots’ Association Chief Operating Officer Mark Nelson referred questions to the pilots’ president, Capt. A.J. Gibbs, who didn’t respond. Phone calls to pilot commissioners were not returned.