The National Transportation Safety Board (NTSB) reports of a collision between two vessels, Crimson Gem and Yangtze Ambition, with no account of injury or pollution.
On January 28, 2016, at 0430 local time, the towing vessel Crimson Gem was pushing 20 barges downbound during high-water conditions on the Lower Mississippi River in Ama, Louisiana, when two of its barges collided with the bulk carrier Yangtze Ambition docked at the bottom of a river bend.
Damage to the vessel and the barges, including a third barge that made contact with the dock, totaled an estimated $575,000. No one was injured nor was any pollution reported.
Restriction to daylight transits
At the time of the accident, the nearest river gage at Carrollton measured 16.1 feet, which was near flood stage, and the current may have been as high as 6.7 mph.
Because of the high-water conditions, the Coast Guard had advised downbound vessels to “consider restricting to daylight transits only” until the gage dropped below 16 feet.
Crimson Gem under way at night
The Crimson Gem, however, was under way at night when the accident occurred. The 20 barges of Crimson Gem tow were four across and five deep, resulting in a tow about 1,185 feet long and 140 feet wide.
The tow operator did comply with Coast Guard Sector New Orleans published procedures on reducing tow size in high-water; towing 20 instead of the usual 35 barges. With a following current, the tow was traveling at 9.3 mph (speed over ground) at 0424.
The pilot put the Crimson Gem’s engines full astern, reducing its speed to less than 1 mph by 0426, in preparation for arriving at its destination about a mile ahead on the river’s left descending bank.
Yangtze Ambition at the bend
The Yangtze Ambition was docked on the opposite bank (right descending), less than
one-half mile before its destination, near the bottom of a tight bend in the river.
The pilot told investigators that as he maneuvered through the bend, the current was pushing him sideways until the tow collided with the Yangtze Ambition.
The starboard two barges at the head of the tow were damaged when they struck the bulbous bow of the Yangtze Ambition. The barge on the starboard corner became wedged under the dock in front of the bulk carrier and broke free from the tow.
The inboard starboard barge, though damaged in the collision, remained with the Crimson Gem tow. The two lead barges on the port side broke away from the tow and were later recovered.
Additionally, the aft-most barge on the starboard side of the tow was damaged
when the aft portion of the tow swung into the dock.
Tow positioning for slide effect
The Crimson Gem pilot told investigators that he should have slowed (backed) down sooner than he did. By slowing down sooner, he would have better positioned the tow to account for the slide effect of the current in the 67-degree river bend.
Consequently, he could have kept the tow farther away from the right descending bank and the Yangtze Ambition.
The pilot also said he would have not slowed down at all in that area had it not been for his destination located less than a mile away. Backing down in the current reduced his ability to control the tow.
The NTSB determined that the probable cause of the collision of the Crimson Gem tow with the moored bulk carrier Yangtze Ambition was the Crimson Gem pilot’s ineffective maneuvering for the prevailing current in a river bend.
Did you subscribe to our daily newsletter?
It’s Free! Click here to Subscribe!