USCG issues AIS safety warning after towboats collide

The US Coast Guard has issued a safety alert highlighting the importance of accurate Automatic Identification System (AIS) data entry and display.

The alert followed a towboat collision on the Mississippi River.

The investigation into that particular casualty was not yet complete, but the USCG said that the incident shows the risks that could be generated by inaccurate AIS data. It said that owners and operators should review and update their procedures to prevent similar casualties from occurring.

The two vessels were thought to be the RC Creppel and Cooperative Spirit, which collided outside of New Orleans in January. The USCG did not name the vessels in the bulletin, but the particulars of the accident matched those of the January 26th collision near Luling, Louisiana. (IMN, January 28th 2020)

Before sunrise, two towing vessels were approaching a bend on the Mississippi River. Neither vessel was broadcasting the total length overall of their tow to other AIS users. The first vessel’s AIS broadcast showed its length at 72ft, but the overall length of the vessel and its two-barge tow was 672ft. The second vessel’s AIS broadcast showed the length at 200ft, but the overall length of the vessel and its 40-barge tow was 1,600ft. The USCG noted that, without the information regarding the total length of the other vessel and its tow, the operators did not have a full understanding of the pending passing situation. As the vessels rounded the bend and completed their turns, they collided, causing the down-bound towing vessel to capsize and sink, resulting in several fatalities.

The USCG said that the proper functioning of AIS was dependent on accurate vessel data entry, including entering the proper ship type code and the full length of a vessel and its tow. The accurate display of a vessel’s full length became particularly important in situations where vessels could not see each other until they were in close proximity.

The USCG strongly recommended that vessel owners and operators use the AIS Encoding Guide to ensure that accurate and up to date information was entered into the AIS, including, but not limited to, the overall dimensions of the vessel and its tow.

Investigations and inspection personnel were encouraged to maintain an acute awareness of AIS data issues while investigating marine casualties, and to initiate corrective actions as needed.