MAREVAL AG
Efficient port handling processes are essential for an export nation like Germany. The German North Sea ports in particular compete with large European seaports such as Rotterdam and Antwerp. At the same time, the maritime industry as a whole faces the challenge of reducing emissions and thus contributing to the German Federal Government's climate targets and the European Union (EU) Green Deal. Efficient and safe traffic management at ports is essential to ensure the safe and timely berthing of ships. A minimum depth must be guaranteed, for which the port infrastructure operators are responsible.
Ensuring a minimum depth is achieved by regularly dredging all harbour locations. The tidal harbours in northern Germany are particularly prone to high levels of sand and silt, making regular dredging particularly important. The previous dredging methods do not comply with ecological principles and are therefore no longer of interest. The so-called re-circulation method has proven its worth in practice, especially for the Port of Emden, which is characterised by a high organic silt content. In contrast to the conventional removal method, where the sediment is removed and dumped at a different location, re-circulation dredging makes use of the microbiological composition of the sediment. Fluid mud (suspended mud layer) is formed from suspended sediment formations, which have a low specific weight when they start to sediment due to their high organic content. The space between the individual particles is occupied by microbial sludge, which stabilises the suspension. The microbial sludge is produced by bacteria under aerobic conditions. The fluid mud that a hold suction dredger picks up in the area of greatest density is therefore exposed to atmospheric oxygen in the thinnest possible layers in the mass before it is released again. To prevent the structure from breaking up, certain requirements are placed on the pump technology used. The microbial slime not only improves the buoyancy, but also reduces the friction between the particles and thus also promotes the navigability of the fluid mud body.
Special dredging technology is required for the re-circulation, which is resource-efficient and must be carried out continuously due to the local sedimentation conditions. The specialised dredging technology and the maintenance volume require the continued use of a vessel on site. The market for dredging services is limited, resulting in an oligopoly. In addition, due to changes in the labour market, there is an increasing shortage of suitably qualified personnel who can operate the vessels 24/7. The high contract costs reflect this situation and are a major cost factor for port infrastructure operators. In the future, costs will continue to increase as more water area needs to be maintained.
The primary goal of the AMISIA project, in which the German Aerospace Centre (Deutsches Zentrum für Luft-und Raumfahrt; DLR) is involved, is to increase the sustainable cost efficiency of port maintenance by largely automating cost-intensive maintenance dredging. The core idea of the project is to design, verify, validate and test a dredger vessel for the re-circulation process that is automated in three automation levels in order to assess the automation and service risks of operating such a vessel in the port.
In AMISIA (Advanced Port Maintenance project: intelligent, sustainable, innovative and automated dredging work), the automation levels defined by the IMO (International Maritime Organisation) are: level one 'Ship with automated processes and decision support', level two 'Remotely controlled ship with seafarers on board' and level three 'Remotely controlled ship without seafarers on board'. In level one, the ship is controlled and monitored by means of assistance systems (for example, an autopilot). In level 2 ships, the ship is steered from shore, but there are still navigators on board. In addition to remote control, this level also includes other automation functions, such as recognising, evaluating and reacting to potentially dangerous ship encounters. In stage 2, for example, docking and casting off manoeuvres are still manual tasks and must be performed by humans. Stage 3 includes highly automated ships that operate autonomously but must be monitored by humans at all times.
The technological automation concept for the three automation levels will be a composition of existing automation technologies. The shipbuilding design and the design of the automated recirculation process will take place in parallel. In close coordination with this, a V&V (verification and validation) concept for the three automation levels will be developed. At the same time, a risk assessment of the concepts will be carried out with respect to the various automation levels. In the context of the development of an operational and business concept, questions concerning the planning of operations and missions as well as the resulting cost-effectivness for each of the three automation levels will be addressed.
An essential part of the project is the continuous testing of the automation concepts in the field. For this purpose, an eMIR research vessel will be equipped with the necessary automation technologies. This will make it possible to identify and adequately address relevant weak points during the project, which will lead to an adaptation of the concept. At the same time, the operating concepts will be tested. The aim is to test each of the three automation levels in the field and to demonstrate safe operation using the developed V&V methods (verification and validation methods).
