Danish Maritime Accident Investigation Board Publishes Report Regarding Kraslava-Atlantic Lady Collision

By Accidents

The Danish Maritime Accident Investigation Board (DMAIB) has published its report regarding the collision between the Kraslava tanker and the Atlantic Lady cargo carrier citing a known blackspot in Denmark’s waters.

Back on November 1st of last year, the Marshall Islands-registered Kraslava chemical/product tanker vessel suffered a collision with the St. Kitts & Nevis-registered Atlantic Lady refrigerated cargo carrier. The accident took place in Denmark’s Drogden Channel, as the vessels travelled through conditions of a dense fog.

Each vessel’s bridge team was aware of the other respective vessel’s presence, but both teams were not accurate in their judgement about the position of the other ship. It was already too late to change course in order to avoid the collision, when the teams were able to acknowledge the situation.

Both vessels had anticipated to experience the closest approach point at the channel’s southern exit/entrance, which had a width of 300 meters and where there was close to no visibility at the given time. During the two ships’ approach to respectively buoys № 17 and № 16, both teams were under the assumption that the other vessel was going to position itself in the channel’s outermost section. At the time of the collision, both ships’ bridge teams were with the sound conviction that the other vessel was on the channel’s wrong side and that their own vessel was positioned in the outer perimeter, but actually both vessels were roughly in the middle section of the channel.

In their report, the investigators reached the conclusion that the collision occurred due to several coinciding factors occurring in a very short time span and within a narrow geographical area. As a result of this the margin for any potential failure was greatly reduced and neither of the two bridge teams was able to react accordingly.

The said factors were such as restricted visibility, the north-easterly current, navigating in a narrow channel, the Atlantic Lady undergoing a significant alteration to its course, a pilot boat being alongside Kraslava. When looked up on an individual basis, none of the stated factors posed a great risk, but when looking at them combined they contributed for creating a small margin between success and failure – a safety margin that depended on whether or not the two vessels were at roughly 50-100 meters to each of the channel’s sides.

Typically, when regarding passing small distances in channels when the respective vessels are going in opposite directions is not problematic but in cases such as this one, when both vessels are to deal with restricted visibility and one ship makes large alterations to its course, the situation tends to become unstable, due to the fact they are unable to rely on just instrumentation because of the close proximity of each ship to one another.

The main factor for the collision was the Atlantic Lady’s particular approach to the Drogden Channel regarding its large turning maneuver. As a result of the restricted visibility and the north-easterly current, which contributed for delaying the start of the maneuver until buoy № 16 was abeam, the turn brought the vessel in the channel’s center where it crossed ahead of the Kraslava.

An analysis made by the Danish Maritime Safety Administration back in 2009 regarding navigation in the southern end/exit of the Drodgen Channel displayed that the area was fairly difficult for navigational procedures and issued recommendations for initiatives towards improving the traffic flow of the area in order to avoid mainly groundings and allusions at the channel’s buoys. According to the appointed investigators, this accident demonstrates that collision risk can also be mitigated by the said initiatives.

AIS Video replay of the collision between Atlantic Lady and Kraslava