The latest instalment of its Good Catch series, focusing on an Automatic Identification System (AIS) Assisted incident.
The incident
An inland towing vessel was upbound in a river pushing 15 barges loaded with fertilizer. The captain was on watch. About two miles before a sharp bend in the river, he saw that a downbound towing vessel would arrive at the bend at approximately the same time.
The Automatic Identification System (AIS) indicated that the downbound vessel was not pushing any barges, so he expected his upbound transit around the bend to be straightforward. The captain lined up his tow carefully. He would leave plenty of room for the downbound towing vessel to pass, as he assumed that it was a “light boat” without any barges, according to AIS.
However, as the captain began to transit the bend, he saw that the downbound tow was actually pushing 9 barges and was positioned to conduct a flanking maneuver around the bend. He immediately radioed the downbound towing vessel and yelled that AIS showed he was not pushing any barges.
The downbound towing vessel radioed back that he had 9 barges loaded with coal and would be flanking the bend. He would try to leave enough room for the upbound tow. But it did not work out that way. While turning hard to miss the downbound barges, the upbound tow ran aground on the inside of the bend, damaging several of the lead barges.
The investigation revealed that the downbound towing vessel had failed to update its AIS to indicate its overall length with 9 barges. AIS showed a total length of 98 feet, but the overall length including the barges was 686 feet. The downbound towing vessel’s previous trip had been a “light boat” transit, properly showing on AIS a length of only 98 feet.
If the AIS on the downbound tow had been updated to reflect a length of 686 feet, the captain on the upbound tow would have slowed down and allowed the downbound tow to clear the bend before proceeding into the bend with his upbound tow.
Actual damage
There was no damage to the downbound towing vessel or barges carrying coal. Three barges on the upbound tow ran aground and were damaged. All three barges required extensive steel repair work, and the fertilizer cargo on one of them was ruined when the cargo hold flooded. Total damages exceeded $145,000.
Potential damages
A collision between the two tows could have been a mess. Numerous barges would likely have been seriously damaged or sunk, and the river could have been closed to all traffic for days while the damaged barges were salvaged, refloated, and moved. Costs could easily have exceeded $1 million without including the costs associated with delays to other river traffic while waiting for the river to be reopened.
What went wrong?
- The downbound towing vessel failed to update its voyage-specific dimensions in AIS to include the length of the barges it was pushing.
- The captain on the upbound towing vessel assumed that the AIS information for the downbound tow was correct and did not try to verify it, even though they would pass in the bend.
- Neither vessel attempted to communicate on the radio to make passing arrangements, especially when it was likely that the tows would pass on a sharp bend.
When you identify a hazard before something goes wrong… it’s a Good Catch.
When you stop an operation before something bad happens… it’s a Good Catch.
When all bridge and navigation tools, including AIS, are properly used… that’s a Good Catch, too!