While the objective of hydraulic structures such as lock gates, navigation river weirs and storm surge barriers are to remain in service, engineers must also be capable to adequately handle their failures. Despite the ongoing development of navigation expertise, design tools, norms, and construction methods, there are still a considerable number of accidents, calamities, and failures that happen to such structures. In addition, the costs of these accidents and failures are growing for several reasons including the increasing complexity and growing demand of waterborne infrastructure.
Navigation accidents are more common than many people realise and hence reinforce the importance of this working group (WG). As examples, there have been ship impact navigation accidents at the German Iffezheim lock on the Rhine River in November 2023 and French Fontinettes lock on the Neufossé canal in October 2023. Accidents like these are difficult to study in whole since investigations are still ongoing. Also, historical accounts of navigation accidents dating back 100 years (or more) are often lost to history and difficult to obtain. Reports on recent navigation accidents are provided in the Appendix A Case Studies. Several types of failures are also discussed in this report. A recent navigation lock failure occurred in January 2024 at the Demopolis Lock on the Black Warier River in the United States, discussed further in Chapter 4.
Accidents and failures to hydraulic structures happen not only when their loads exceed the design strength. Other possible causes are lack of inspection and maintenance, improper operation, extreme weather events and navigation errors. In addition, there are often combinations and complex sequences of events that may lead to accidents.
This PIANC WG 241, was assembled to collect information on navigation accidents and provide an assessment and lesson learnt. Case studies of previous accidents are a key part of this WG report and are included as noted above in Appendix A. Chapter 3 provides a summary of the case studies. This WG did not have time to assemble case studies for the most recent navigation accidents such as at Iffezheim lock, but the collected case studies are still quite comprehensive.
