- The NTSB report highlighted the importance of managing simultaneous operations and identified it as a contributing factor to the collision.
- The report also emphasized the use of digital selective calling (DSC) on modern VHF radios to communicate distress signals effectively.
The National Transportation Safety Board (NTSB) has released its investigation report on the collision between containership MSC Rita and fishing vessel Tremont which happened on October 28, 2022, reports IIMS.
On October 28, 2022, about 0036 local time, the containership MSC Rita and the fishing vessel Tremont were underway in the Atlantic Ocean, 55 miles southeast of Chincoteague, Virginia, when the two vessels collided. The 13 people aboard the Tremont abandoned the vessel and were rescued by Good Samaritan vessels and a US Coast Guard helicopter. No injuries were reported. An oil sheen was reported; a potential of up to 31,000 gallons of diesel fuel were lost with the fishing vessel. Damage to the vessels was estimated at $4.75 million (Tremont) and $1.5 million (MSC Rita).
While the containership MSC Rita was transiting southbound in the Atlantic Ocean, southeast of Chincoteague, early in the morning, the fishing vessel Tremont was transiting north-northeast in the same area. Shortly after the Tremont passed ahead of the MSC Rita, the Tremont suddenly turned back toward the containership. At that time, the mate on board the Tremont was operating the vessel and attempting to fix the vessel’s gyrocompass, which the captain stated had been off by 10° since 4– 5 days into the trip (investigators were unable to determine what was wrong with the gyrocompass). As he worked to fix the gyrocompass, the mate left the vessel’s autopilot engaged.
The Tremont’s autopilot required heading feedback from the vessel’s gyrocompass and a user to input the heading setpoint (desired course). As a result of this heading feedback and user input, the Tremont’s autopilot then output the calculated rudder commands to correct any heading deviation. The amount of rudder used was a function of heading setpoint deviation, the rate of change in the deviation, and the mean deviation. Therefore, as the mate adjusted the gyrocompass to troubleshoot the cause of its error, the autopilot processed the heading feedback, causing the vessel to turn to starboard and toward the MSC Rita, striking the containership on its starboard bow.
In the time leading up to the collision, the Tremont mate was standing watch alone in the wheelhouse at night. The vessel was equipped with radar and AIS, which was transmitting but not displaying properly, and the mate was aware of this issue. The vessel’s radar was functioning, and visibility conditions were good (8 miles). The 1,100-foot-long MSC Rita would have presented a substantial radar target, and since the containership was displaying navigation lights, the mate should have been able to see it visually. However, the Tremont mate told investigators that, while he was on watch, he was preoccupied with troubleshooting the gyrocompass. The mate stated he did not see the MSC Rita on radar nor visually until immediately before the collision.
As the Tremont turned back toward the MSC Rita, the containership’s second officer sounded the vessel’s whistle, but the Tremont mate did not hear it. Therefore, the mate’s distraction due to troubleshooting the gyrocompass prevented him from maintaining a proper lookout, and he was thus not aware of the approaching MSC Rita. The MSC Rita bridge team monitored the Tremont crossing ahead and to starboard of the containership at 0029 (about 7 minutes before the collision) when the two vessels were about 2.3 miles apart.
The Tremont then unexpectedly turned back sharply toward the MSC Rita a few minutes later. When a mariner is in doubt about a vessel’s erratic movements or an operator’s intentions, they should sound blasts of the whistle to signal uncertainty. About 0034, when the fishing vessel was about 1.3 miles away, the MSC Rita second officer sounded five short blasts of the whistle. However, the Tremont mate did not hear these signals, and the Tremont continued on the same heading, closing on the MSC Rita. Although the MSC Rita helmsman switched to hand steering and came hard to port at 0036:05 to avoid a collision, there was not enough time to maneuver the containership out of the path of the Tremont, and the fishing vessel struck the MSC Rita about 20 seconds later.
The collision resulted in hull damage to the Tremont on its port side and bow. The crew found water in the engine room, a bilge alarm went off in the shaft alley, and within 10 minutes of the collision, flooding was found to have reached the main deck above the fish hold. The crew did not determine the source of the rapid flooding and subsequently abandoned the vessel. Based on witness statements and photographs of the vessel before it sank, the flooding was likely caused by port side shell damage at the engine room and/or the vessel’s forepeak.
After the collision, the Tremont captain used VHF to signal distress, but because of the distance between the vessel and the nearest Coast Guard station ashore, the distress call was weak, and Coast Guard watchstanders heard only “MAYDAY” and the vessel’s name. The captain used the vessel’s satellite phone to call 911 and communicate the nature of the emergency, as well as the vessel’s position.
The Tremont was equipped with VHF-digital selective calling (DSC); by pushing and holding the red distress button on the radio, a VHF-DSC call could have communicated the nature of the distress and the latest position of the vessel to nearby vessels, unlike a satellite call, and would have continued to transmit distress messages until the call was acknowledged.
The National Transportation Safety Board determines that the probable cause of the collision between the containership MSC Rita and the fishing vessel Tremont was the Tremont mate not maintaining a proper lookout and keeping the autopilot engaged while troubleshooting the vessel’s gyrocompass, which resulted in the vessel turning into the path of the MSC Rita.
Conducting maintenance on critical equipment while underway
In this casualty, maintenance of the gyrocompass was being conducted while the vessel was underway with its autopilot, which was receiving heading information from the gyrocompass, engaged. Simultaneous operations, often referred to in safety management systems, is a situation where two or more operations occur in the same place at the same time and may interfere with each other. Managing simultaneous operations is an essential element of safety management and safe vessel operation. Before beginning work, mariners should identify hazards associated with working on one piece of equipment that may affect another, such as sensors feeding information to other equipment, and manage those risks to avoid unsafe conditions.
Using VHF-DSC to communicate distress
Modern VHF radios are equipped with digital selective calling (DSC). Pressing the VHF-DSC button alerts search and rescue authorities and nearby vessels, and automatically provides the vessel’s position. Time permitting, mariners can also select the nature of distress on the radio and verbally communicate with nearby responders. When a vessel is in distress, mariners should use all available means to signal emergency responders, including VHF-DSC.
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