On May 10, 2019, the 754-foot-long, 122-foot-wide liquefied gas carrier Genesis River collided with a 297-foot-long tank barge being pushed ahead by the 69-foot-long towing vessel Voyager. As a result of the collision, two cargo tanks in the barge were breached, spilling petrochemical cargo into the waterway, and a second barge in the Voyager tow capsized.
The Genesis River had been outbound on the Houston Ship Channel when, a few minutes prior to the collision, it met the inbound 740-foot-long, 120-foot-wide liquefied gas carrier BW Oak in the intersection of the Houston Ship Channel and the Bayport Ship Channel, known as the Bayport Flare. After the Genesis River and the BW Oak passed each other port side to port side, the Genesis River approached the southern terminus of the flare and a 16-degree port turn in the channel. As the Genesis River exited the flare and entered the turn, it crossed over to the opposite side of the Houston Ship Channel and subsequently struck the starboard barge in the Voyager’s two-barge tow. The Genesis River’s bow penetrated through the barge’s double hull and breached its center cargo tanks. The force of the collision capsized the port barge in the tow, and the Voyager heeled considerably before its face wires parted and the vessel righted itself. Over 11,000 barrels of reformate, a gasoline blending stock, spilled into the waterway from the starboard barge’s breached cargo tanks.
The Houston Ship Channel was closed to navigation for two days during response operations and did not fully open for navigation until May 15. The total cost of damages to the Genesis River and the barges was estimated at $3.2 million. The cost of reformate containment and cleanup operations totaled $12.3 million. There were no injuries reported.
The probable cause of the collision between the liquefied gas carrier
Genesis River and the
Voyager tow was the
Genesis River pilot’s decision to transit at sea speed, out of maneuvering mode, which increased the hydrodynamic effects of the Bayport Flare’s channel banks, reduced his ability to maintain control of the vessel after meeting another deep-draft vessel, and resulted in the
Genesis River sheering across the channel toward the tow.
The safety issues identified in this accident include the following:
Challenges of navigating large vessels in the Bayport Flare area of the Houston Ship Channel. Due to the narrowness of the channel, the large amount of vessel traffic, and the size of the vessels transiting the channel, the Houston Ship Channel is challenging to navigate and requires significant training and experience. The asymmetric shape of the channel in the vicinity of its intersection with the Bayport Ship Channel, known as the Bayport Flare, makes navigation particularly difficult due to varying hydrodynamic forces acting on a vessel’s hull. When larger vessels meet in the intersection while transiting at a relatively high speed, the risk of loss of control is much greater.
Vessel speed while transiting a narrow channel. Transiting a narrow channel at or near a vessel’s maximum speed provides little room for error and little ability to increase propeller wash over the rudder to recover if control is lost. The margin for error is even more limited on ships with slow-speed, direct-drive diesel propulsion engines transiting at Nav. Full (navigation full), an engine mode designed for higher speeds in open ocean waters where the ability to change engine revolutions per minute (rpm) on short notice is significantly restricted.
As a result of this investigation, we made four new safety recommendations to K-Line Energy Ship Management and the Houston Pilots, and reiterated two recommendations to the US Coast Guard.
