Report Released on Fatal Mooring Accident
The Danish Maritime Accident Investigation Board has released a report into the fatal mooring accident that occured on 3 October 2013 on the Antigua & Barbuda registered container ship Atair J.
The vessel had arrived in the Port of Aarhus for discharging and loading general cargo in containers. Atair J had a busy schedule that included five North European ports a week.
On the day of the accident, there was a strong southeasterly breeze that made it difficult to berth the ship. Therefore, it was decided to use the spring line to hold the bow in place and use the rudder and propulsion to get the stern alongside. The spring line parted shortly after having been secured to the quay bollard. It struck the bosun who was standing in the enclosed forecastle causing fatal injuries.
The accident occurred as a result of several factors, such as the weather conditions, wear of mooring lines and design of mooring arrangements. These factors coincided and created a hazardous situation. The circumstances on deck were not much different from any other arrival in Aarhus or in another port in adverse weather conditions.
Atair J approached the berth bow first, using the spring line to hold the ship in position while getting the stern alongside. This manoeuvre, together with a strong breeze, created considerable tension on the spring line causing it to break, whip back onto the forecastle, around a pillar and then hit the bosun. It has not been possible to establish the exact path of the rope, but it is likely that it hit one or more obstacles before it hit the pillar and bosun, thereby making the path of the rope unpredictable and difficult to reconstruct. It is uncertain whether the bosun was struck by the end of the broken rope that travelled through the fairlead or by a loop created by the sudden slack in the rope.
The crewmembers did not realize that the mooring rope was in a questionable condition. It can be difficult to judge the condition of the mooring rope without in-depth knowledge about the specific type of rope, its age and prior history. During the actual mooring operation, the crewmembers had limited options for discarding a rope as no extra ropes were readily available on the winches. The ship did not have a formalized way of evaluating the condition of the ropes. Therefore, the evaluation was based on the judgment by the crewmember and not the actual limitations stated by the manufacturer of the rope.
The crewmembers at the forward mooring station were aware that the rope was under a considerable tension and thus slackened it little by little. When they became concerned about the tension on the rope, they positioned themselves in places they considered to be safe areas. However, investigations by the DMAIB have previously found that it is inherently difficult to judge certain areas on mooring decks as safe and others as unsafe – as a rope that breaks can have an unpredictable path dependent on where it breaks, its load and angle.
Risk factors related to operations on mooring decks are difficult to assess. There is a difference between the way in which risk is perceived and described in formal risk assessment forms and the way in which risk is perceived in real-time operations. Risk factors are not always easily identifiable and recognized by a crewmember. The lack of available evidence will thus make it difficult to foresee what will happen in the immediate future. Real-time risk-awareness is focused on the risks that individuals are facing in specific situations. This risk awareness is biased by the practicalities of getting the job done and the individual’s prior experiences of successful outcomes of any given action.
Even though risk assessments are made, they seldom address the difficult choices that deck hands have to make in their everyday work – e.g. the choice between slackening the rope to avoid breaking it or holding the ship in position with the risk of breaking the rope.
There can be a conflict between the master’s perspectives on risk and the deck crewmembers’ view of the hazards presented by a situation. On deck, the immediate priority is to avoid breaking the mooring lines, which is based on a subjective evaluation of the situation. Therefore the crewmembers on the forecastle on Atair J slackened the rope without prior permission from the master, knowing that he would disapprove.
The crewmembers on deck would not necessarily know the master’s plan for getting the ship alongside. They had an immediate sense of when a situation would become dangerous, without the officers on the bridge realizing the seriousness of the situation. Furthermore, the master had multiple concerns during manoeuvring – with an overall priority of getting the ship alongside, but with little or no overview of the situation on deck. With no direct communication, the master’s perception of risk would not be aligned with that of the deck hands.
Only little space was available on the mooring deck for carrying out the normal operations. This influenced the decision not to have snap-back zones painted on deck. The underlying thinking in painting snap-back zones is that the mooring rope parts in a specific place when it is under tension within a specific angle. However, Atair J used a variety of mooring configurations dependent on the design of the berth and position of the ship. Therefore, it was not possible to define safe and unsafe areas without creating a confusing workplace on the mooring deck.
The operator of the winch had little or no overview of the mooring situation and therefore relied on instructions from the bosun. Once the spring line was secured, the crewmembers had to prepare the head lines, throw heaving lines, guide the ropes from the storage drum to the tension drum and communicate with the linesmen ashore – while giving the winch operator instructions. In this stressful environment, the design properties of the deck area challenged the deck hands’ ability to create an overview of the situation and assess the real-time risk factors.
The accident on Atair J occurred because excessive tension was applied to a worn spring line, while the officers on the bridge were manoeuvring the ship in an attempt to get it alongside the berth in adverse weather conditions. The excessive tension on the spring line was the result of using the propulsion and rudder, while holding the ship with the spring line in order to get the ship alongside.
It is not uncommon that mooring ropes part under different adverse circumstances such as strong winds, malfunctioning winches, strong currents and tides etc. Though the parting of the mooring rope was the determining accidental event, it is not a sufficient explanation for understanding why the normal task of mooring the ship resulted in a fatality. A determining factor for the fatality was the fact that the crewmembers were challenged by the basic design of the mooring arrangement, i.e. lack of overview, small working area and exposure to ropes under tension. In that workplace environment with changing operational circumstances, the accident occurred.
Furthermore, it is inherently difficult to identify and assess the specific risk factors, while negotiating these risks with the goals of everyday work – e.g. working fast to get the ship alongside in ad-verse weather conditions. This accident is an example of the difficulty encountered in assessing the risk of being hit by a broken mooring line because the bosun was standing in what was considered a safe place during a normal mooring operation.
The flag State of Atair J assisted the Danish Maritime Accident Investigation Board in the investigation of this accident. The report is available here.