Dense fog was a leading factor in a collision involving two freighters in the Houston Ship Channel, the U.S. Coast Guard said.
The cargo vessel Harvest Sun and the tanker Charleston collided shortly after 0800 on Dec. 13, 2011, near Texas City. The impact caused the U.S.-flagged Charleston to run onto a small bank, where it sat until an assist tug helped pull it off. The accident led to a temporary shutdown of the channel, but no injuries or ecological damage.
"I think the fog was a huge contributing factor to this. That's probably the safest thing I can say right now," said Lt. Derricka Fortson, chief investigations officer at Marine Safety Unit Texas City. She cautioned that the cause was still undetermined.
It appears the pilots aboard both vessels "were doing everything they were supposed to be doing" leading up to the collision, Fortson said.
The National Weather Service issued a dense fog advisory for Greater Houston on Dec. 13 that was projected to last until the next morning. Visibility was estimated at less than a quarter-mile, and parts of the channel were in the process of being shut down when the accident happened.
"Houston Pilots had already suspended boardings just before the accident due to fog," Fortson said. "These two ships were the last of several vessels to get out or come in since they were already underway when the boardings were suspended."
The 623-foot Harvest Sun was outbound from Texas City while the 635-foot Charleston was inbound toward Houston when the accident occurred. They met just north of the Texas City Dike — a five-mile strip that extends from Texas City toward the Bolivar Peninsula near the entrance to the ship channel.
The two vessels had arranged for a port-to-port passage, "but they got too close together on the passage and that's how they hit," Fortson said.
Harvest Sun suffered a 7-foot-by-13-foot hole in the port bow area just above the vessel's name. Charleston sustained "insets to the port quarter" and damage to lifeboats on the port side, as well as "undetermined damage to the port superstructure," Fortson said.
Harvest Sun was empty when the collision occurred. Charleston was carrying 51,000 barrels of acetone, a chemical used in nail polish remover.
Charleston, built in 1983, is owned by U.S. Shipping Corp. The Marshall Islands-flagged Harvest Sun was built in 2001. It is owned by HSU Shipping Co., and was operated by Wilhelmsen Ship Management. Officials at U.S. Shipping and Wilhelmsen Ship did not return messages seeking information on the accident.
Fortson said pilots aboard the two vessels had communicated with each other before the accident. She said it was very likely that lookouts and fog horns were being used as required, adding that the investigation had yet to confirm those details.
J.J. Plunkett, the port agent for Houston Pilots Association, said he was unable to comment on the pilots' actions before the collision, citing the pending investigation.
Once the fog cleared, both vessels sailed under their own power into the Port of Houston for inspection.