The National Transportation Safety Board (NTSB) determined that the Miss Susan, a shallow draft towing vessel with two barges, and the Summer Wind, a deep draft bulk carrier, collided on March 22, 2014, because the towing vessel crossed the Houston Ship Channel, impeding the passage of the bulk carrier that was transiting inbound, which could only transit within the channel.
Thousands of gallons of fuel spilled
The collision resulted in the release of 168,000 gallons of fuel into the Houston Ship Channel from the breach of the forward barge and the hospitalization of two crewmembers on the Miss Susan for inhalation-related injuries. As a result, the NTSB recommended that crews on vessels transporting hazardous materials receive appropriate training, personal protective gear, and access to direct-reading air monitoring equipment.
A failure to communicate
Prior to the accident, visibility in the Houston Ship Channel was restricted and nearby there was towing vessel traffic. Contributing to the accident was the failure of the Summer Wind’s master and the Houston pilot on board the Summer Wind to set a safe speed or discuss the tow traffic in the waterway. Also, the captain on the Miss Susan and the Houston pilot failed to establish early radio communication as they transited through Bolivar Roads Precautionary Area, a high traffic area which includes several intersecting waterways and requires vessels to navigate with caution.
At the time of the accident, the Summer Wind, which was traveling at full speed, 12 knots, had little room to maneuver. The margin of safety would have increased with a slower transit speed. However, according to navigation rules, the Miss Susan should not have crossed the main channel ahead of the Summer Wind.
Unacceptable response
Following its investigation, the NTSB reclassified a recommendation to the U.S. Coast Guard from “Open?Acceptable Response” to “Open?Unacceptable Response,” and also reiterated the need to develop and implement a policy to ensure adequate separation of vessels in the precautionary areas in the Houston Ship Channel. The report also reiterates a recommendation to graphically delineate precautionary areas on appropriate Houston Ship Channel nautical charts so they are readily identifiable to mariners.
The report also notes that leading up to the accident, the U.S. Coast Guard Vessel Traffic Service staff was monitoring several radio channels simultaneously. The watch standers missed the radio communications about the developing close quarter’s situation.
“A safe transit through congested waterways requires a team effort,” said NTSB Chairman Christopher A. Hart.
To view the full report including findings, the probable cause, and all recommendations, click on the following link: http://www.ntsb.gov/news/events/Documents/2015_Houston_BMG_DCA14FM008_Abstract.pdf.
