# The ConTAD Project: Detection of Multi-Container Loss for Safety of Navigation +
## 2 Review of the MSC Zoe Accident
### Phase Model for the Description of Container Loss Accidents  
In this section, a phase model for the analysis of the MSC Zoe accident is proposed. The main elements are a preparation phase, where precautions are taken to avoid any incidents at sea. This includes the process of passage planning, e.g., choosing a deep water route, as well as the proper stowage and securing of the cargo with appropriate stowing gear. Additional advice can be found in \"5.3 General loss prevention advice\" [6] (p. 25). If the voyage is performed without any accident it is terminated in the port of destination. Should an incident happen, the incident phase begins. In case of the MSC Zoe, this was the loss of the first containers. This phase continues until the incident is recognized and the decision to act is made. This phase is called recognition/alarm phase. In case of the MSC Zoe, it took another 30 min from the recognition that containers have been lost to the decision to turn the ship upwind, which only was made because another container stack was observed collapsing. In the response phase, the crew immediately takes measures to control the situation, such as stabilize the ship and inform relevant authorities. For example, on the MSC Zoe a course change was performed to stabilize the ship and avoid further container losses. Additionally, checklists like \"5.4 What to do if a container is lost\" [6] (p. 25) are followed to take proper actions. After stabilization of the situation and the prevention of additional container losses, the containment phase begins. The main goal is here to bring the ship safely to port with no further container losses. Also, a thorough assessment of the situation is performed, and the damage is estimated. An additional focus is on the reduction in the environmental and economic impact of the accident. As soon as the ship reaches port, it enters the voyage termination phase, and a final assessment of the accident is performed. For the MSC Zoe, it took over two weeks and required the complete discharging of all cargo in the port of Gdansk to determine how many containers were lost. Additionally, there is a salvage phase involving other companies and ships to clean up as much of the lost cargo and containers as possible. In case of MSC Zoe, the cleanup was suspended after 11 months though there was still a quarter of the lost cargo floating in the North Sea [5].  
Figure 1 already shows the goals set for the ConTAD approach. First, the incident and recognition phase shall be shortened to a few minutes. This will be achieved by automatic detection of container loss and alarming the ship's navigation crew. Second, a very fast situation assessment is made possible, since the exact number of lost containers and their cargo, especially DG, is known the moment they are lost overboard. Also, ships in the vicinity are warned of the dangerous floating containers and authorities are automatically informed. Third, by enabling the location of lost containers with DG, the environmental impact of the accident is reduced through fast salvage operations. Also, the immediate and automated information of cargo owners reduces the economic impact in case of time sensitive goods. High-value goods can also be located and salvaged to reduce the overall damage. Finally, the salvage phase following such accidents will be significantly reduced by  
knowing the precise locations of lost containers and therefore be less costly, depending on the locally available salvage capacity. To achieve these goals, ConTAD will take advantage of existing systems by improving their interactions and expanding their functionality.