The National Transportation
Safety Board has issued its report on a May 8, 2020, incident in which, at
about 4.55 p.m. local time, the anchored general cargo vessel Nomadic
Milde collided with the anchored bulk carrier Atlantic Venus on
the Lower Mississippi River near New Orleans, La.
After the Nomadic Milde began
to swing and drag its anchors in the current, it collided with the Atlantic Venus,
which had been anchored directly behind it, and then struck a nearby chemical
dock and grounded on the bank. No injuries were reported. The Nomadic
Milde released an estimated 13 gallons of lube oil into the river.
Damage to both vessels and the dock was estimated at $16.9 million.
ANALYSIS
In its analysis the NTSB says that
the Nomadic Milde’s positions and headings suggested that the ship
did not initially settle at its original anchor position.
“After the starboard anchor was let
go, the ship moved about 730 feet away from the original starboard anchor drop
position towards the right descending bank, a distance double the amount of
chain that was set on the anchor, indicating that the starboard anchor likely
dragged. The initial 6-minute anchor drag began within 10 minutes of when the
pilot had informed the master that the anchoring was finished,” says the
report. “The pilot departed the bridge while the vessel was still moving,
although he said he had no concerns about the Nomadic Milde holding anchor. Had
he noticed the initial drag of the Nomadic Milde, he may have
remained with the vessel. Additionally, had the bridge team detected the
initial drag before the pilot departed the vessel, or if the master had voiced
any concern, they may have been able to request that the pilot remain with the
ship to attend to the issue.
“The second officer and chief
officer both stated that the ECDIS was their means
to monitor the Nomadic Milde’s position at anchor. Monitoring a
ship at anchor, especially in an area where the risks of nearby hazards and
weather and current are present, requires a continuous state of vigilance and
the use of all available means to determine whether a vessel is dragging or
not. The second officer had set an ECDIS anchor watch alarm, which would have
sounded had the vessel moved beyond the set radius. Neither the second officer
nor chief officer recalled hearing the anchor alarm activate, and, given that
the initial estimated distance from the stern of the Nomadic Milde to
the bow of the Atlantic Venus was 490 feet, the anchor watch
alarm radius setting of 590 feet was too large to provide for a timely alarm of
the ship dragging. From 1551 to 1557, just before the change of the watch
between the second officer and chief officer at 1602, the ship began to swing
to starboard and dragged anchor, moving about 800 feet over about 6 minutes.
Although the chief officer noticed that the vessel was not in the center of the
anchor watch circle when he relieved the watch, he did not question if the ship
had dragged or check whether the ship was remaining securely at anchor.
“The officers on anchor watch on
the Nomadic Milde had adequate time and means to check whether
the ship was remaining securely at anchor. At the watch relief, the chief
officer did not cross-check the ship’s position after he noticed that the Nomadic
Milde was not in the middle of the ECDIS anchor watch circle. Even
after the initial alert by the Atlantic Venus to monitor their
holding position, the chief officer did not take any follow-up action to
address the concern, only communicating that their engines were ready on short
notice. There was no evidence of either watch officer checking the ship’s
position at frequent intervals or by means other than the ECDIS watch alarm to
determine if the ship was secure at anchor or not. Although ECDIS is a useful
tool in determining a ship’s position at anchor, the ship’s radars would have
provided information for the crew to determine or crosscheck if the range to a
vessel or object had decreased, or if the ship had moved while at anchor. There
was sufficient evidence to alert the bridge team that the Nomadic Milde was
not holding well, and, had this been detected, the master could have been
alerted earlier, and, in turn, there would have been sufficient time to
undertake necessary measures to address the problem.
“By the time the Nomadic
Milde’s master was called to the bridge, he had lost about half the
original distance between his vessel and the Atlantic Venus in
which to react to and mitigate the situation. Knowing that a pilot was required
to get under way in the Lower Mississippi River, he contacted New Orleans VTS
and the ship’s agent to request a pilot but was informed he would have to wait
hours. Seven minutes before the collision, the main engine was ready for use on
the bridge—but VTS had told the Nomadic Milde not to heave
anchor and to maneuver only with their engine until a pilot arrived. The master
followed the instructions from VTS, keeping the anchors out. However, this
severely limited the bridge team’s ability to control the vessel in the strong
current, even while using the main engine up to full ahead, the bow thruster,
and rudder.”
PROBABLE CAUSE
The National Transportation Safety Board determines that the probable cause of the collision between the Nomadic Milde and Atlantic Venus was the bridge team on the Nomadic Milde not effectively monitoring the vessel’s position and therefore not detecting that the vessel was dragging anchor and had moved from its original position during high-water conditions in proximity to other vessels.
https://www.ntsb.gov/investigations/AccidentReports/Reports/MAB2115.pdf
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