Executive Summary
The information in this report is preliminary and will be
supplemented or corrected during the course of the investigation.
On Monday, March 9, 2015, at about 1231 central daylight
time, the Liberian registered, 623-foot-long bulk carrier Conti Peridot and the
599-foot-long Danish flagged chemical tanker Carla Maersk collided near buoys
89 and 90 in the Houston Ship Channel, Upper Galveston Bay, southeast of
Morgan’s Point, Texas.
After weighing anchor offshore at the entrance to the
Houston Ship Channel and boarding a pilot, the Conti Peridot proceeded inbound
at about 0930 up the channel to City Dock 24 to discharge its cargo of steel
rolls. About the same time, the Carla Maersk departed Kinder Morgan Terminal in
Galena Park, Texas, with a pilot on board and carrying 216,049 barrels (bbls)
of methyl tertiary butyl ether (MTBE) outbound for Venezuela.
The Conti Peridot got under way in good visibility. The Carla
Maersk departed in light rain with a low cloud ceiling. As the vessels
proceeded with their transits, radio transmissions between vessels reported
developing fog in the Houston Ship Channel. At 1130, Houston Pilots suspended
pilot boarding at the entrance channel due to fog. Piloted vessels already
under way continued their transits.
An hour later, with visibility estimated by the Conti
Peridot pilot to be a ship’s length, preliminary data indicate both vessels
were at half-ahead traveling just over 8 knots as they approached each other
south of Morgan’s Point.
The pilot on the Conti Peridot was having trouble returning
to the channel center after passing another vessel and initiated a port-to-port
passing arrangement with the pilot on the Carla Maersk. After this arrangement
was made, preliminary data show the Conti Peridot moved to the left side of the
channel and then back to the right. At this time, the Conti Peridot pilot
ordered hard starboard and full ahead in an effort to counter his vessel’s
anticipated movement to the left. The pilot on the Conti Peridot warned the
pilot on the Carla Maersk that he was coming back across the centerline of the
channel toward his vessel. When the pilot on the Carla Maersk saw the bow of
the Conti Peridot emerge from the fog, he ordered hard starboard and full ahead
in an effort to avoid what he perceived to be an imminent collision.
The Conti Peridot’s bow struck the port side of the Carla
Maersk, penetrating the two port wing ballast tanks and the no. 4 port cargo
tank, which held about 15,495 bbls of MTBE. After the impact, the Carla Maersk developed
a port list, and the crew took action to move cargo and ballast to correct the
list. No injuries were reported onboard either vessel.
MTBE is a colorless, flammable liquid with a turpentine-like
odor; its vapors are heavier than air, and it is miscible in water. The Houston
Port Authority initially responded to the incident due to the release of
hazardous materials, and a Unified Command was established soon after the
collision to manage the emergency response operations and planning.
The US Coast Guard classified the accident as a major marine
casualty. The National Transportation Safety Board (NTSB), the lead federal
investigative agency for the accident, launched a team of investigators and a
Board Member to the scene the following morning.
While on scene, investigators retrieved data from vessel
voyage data recorders (VDR), electronic navigation systems, and alarms as well
as closed circuit television systems along the waterway. Coast Guard Vessel
Traffic Service (VTS) Houston data were also collected. Investigators noted the
operational condition of propulsion machinery and tested the steering systems
aboard each vessel.
They also interviewed officers and crewmembers from both
vessels, the two Houston pilots, and VTS watchstanders. Drug and alcohol
testing was conducted for relevant personnel. Results are pending at this time.
Parties to the investigation are the US Coast Guard, Carla
Maersk owner, Conti Peridot owner, flag administrations for Liberia and
Denmark, Houston Pilot Association, and the Board of Pilot Commissioners for
Harris County Ports