The German Federal Bureau of Maritime Casualty Investigation (BSU) has published a report on an accident involving the Finnish-flagged heavy-lift vessel MERI while transporting a mobile harbour crane from Rostock to Esbjerg via the Kiel Canal.
Documentation indicates the ship and cargo exhibited a permissible height to pass the bridges on the NOK safely. However, while passing beneath the first bridges, the high bridges at Holtenau, on 30 November 2022, the mobile harbour crane’s tower head struck the hollow box girders of both carriageways of the bridges.
The force of the impact broke the lashings that were securing the 643 t crane to the deck. This allowed the crane to tilt far enough toward the stern to pass under both bridges. In the process, it lost eight counterweights, three of which fell into the water. In both cases, the crane then tipped forward again after passing beneath due to its centre of gravity, crashing back onto the deck with its running gear and supporting pads.
The crane was destroyed in the process. The MERI’s deck was also damaged. It was deformed and the crane jib penetrated part of it. The bridges sustained considerable damage. The bridges and the NOK were temporarily closed to all traffic. In particular, automobile traffic was seriously disrupted until the primary damage to the bridge was repaired on 21 December 2023. The cost of the bridge repairs stood at some EUR 6 million. Two investigators from the BSU immediately went to the scene of the accident to secure evidence and inspect the damage to the bridges, the MERI and her cargo, as well as to establish the consequences for safe passage of the canal as far as was necessary and possible.
In retrospect, the allision could have resulted in serious personal injury, although fortunately this was not the case. The MERI had cast off in the lock about eight minutes before the allision. However, since the deckhands working on the aft deck of the MERI had cleared and left the manoeuvring station immediately, nobody was in the crane’s danger zone.
The crane remained on deck and did not have to be laboriously salvaged from the fairway of the NOK. The consequences of the accident for road traffic as a result of the bridge closures were significant.
Main causes of the accident
– the transport was planned and contractually agreed on the basis of an incorrect transport drawing;
– an accurate transport drawing was not submitted subsequently. The actual tower height was not provided;
– the crane was loaded without using the information in the stowage plan. The different attachment points to the crane that was actually to be transported could possibly have been noticed;
– a clearly visible shipping label was attached to the loaded crane, indicating an incorrect tower height;
– when the special dispensation was granted, the submitted transport drawing could only be reviewed to determine whether the drawing was correct with regard to the measurements entered;
– it was not possible to measure the height in the lock. The crane’s tower height specified by the ship was not called into question for the verification.
Conclusions
At the crane’s manufacturer, numerous people from several departments are involved in preparing for transport and loading many different products. The processes should be controlled such that transport operations are always carried out on the basis of an up to date, correct and accurate transport drawing.
– To avoid similar accidents in the future, ship operators, masters and the canal’s Administration should each take their own appropriate measures for their own areas of responsibility, regardless of the overall legal responsibility.
The transport manual
Transport manuals should be developed as intended at Meriaura Ltd. and meet the company’s internal standards. The information contained should be complete, accurate and up to date. The process should conclude with the originator approving the document. Similar transport operations should only be carried out on the basis of approved transport manuals. Irrespective of the lack of legal necessity, these should be used so that less obvious deviations, such as the incorrect crane height in this case, can be recognised.
Loading
In the view of the BSU, the deviation from the existing transport drawing should have been noticeable during a horizontal measurement of the loaded crane. An identified deviation would have led the shippers responsible to ask why the deviation existed. It may then have been recognised that a different crane than that planned for had been loaded. In any case, all information available for loading should be used to check the loading operation in respect of planning, even if there is no special reason to do so. As a matter of principle, loading should only be carried out on the basis of approved transport manuals.
Admission for passage (special dispensation)
From the perspective of the BSU, WSA Kiel Canal should be guided by the recommendation for action for VTS NOK when reviewing applications for a one-off height permit and always obtain a comprehensible height certificate (approved measurement report) for the object in question (ship/cargo). Ship general arrangement plans are generally only suitable to a limited extent, as they are often not adapted to the individual and current ship in the case of series construction or subsequent modifications. Traceable measurement reports can be created on the basis of a tower height determination. Information on determining tower heights can be found in the expert’s report in Annex 9.3. WSA Kiel Canal should publish corresponding information in advance so that ship operators can request suitable height measurements and submit approved measurement reports in a timely fashion.
Actions taken
The crane’s manufacturer has taken the following action to prevent similar accidents in the future:
– technical drawings are produced only on the basis of a formal requirement made within the company;
– transport drawings are created according to the dual control principle, with the assistance of an external service provider;
– transport drawings are provided with a cover sheet that includes the basic data of the cargo, such as the height. The connection between cargo and transport drawing is established by the inclusion of a serial number;
– transport drawings are reviewed before being sent to the logistics company concerned, and approved if the result is positive;
– the height of erected cranes is measured and the result documented.
The BSU believes that the action taken is credible and sound. Based on the information provided, the BSU suggested that the principle of dual control should be documented in the title blocks of the transport drawing/cover sheet. In addition to the originator, the name of the reviewer and date of the review should be given. Based on the measures taken, the BSU refrains from making corresponding safety recommendations to the crane’s manufacturer.
Download the full report on the MERI in pdf format: BSU: Bridge allisions on the Kiel Canal
