Purpose: Engineering knowledge continuity is crucial for the life cycle management of long-lived and complex assets, such as nuclear plants, locks and storm surge barriers. At the storm surge barriers in the Netherlands, engineering knowledge continuity is not yet fully assured, despite long-standing efforts. This study aims to explore the relationship between system characteristics, the organizational demarcation of maintenance and operation and the challenges in achieving engineering knowledge continuity and provides suggestions for improvement of theory and policy. Design/methodology/approach: Ten semi-structured interviews were conducted with professionals from various backgrounds in construction, engineering and asset management of the Dutch storm surge barriers, augmented with visits to barriers and barrier teams. A thematic analysis was used to identify and describe the challenges to engineering continuity, their origins and potential solutions. We reviewed knowledge management policy documents and asset management consultancy reports to validate the findings. Additionally, we engaged in frequent interactions with professionals at the barriers. We achieved saturation and validation once no new issues were raised during these discussions. Findings: The thematic analysis developed multiple themes describing the challenges to engineering continuity, their origins and potential solutions. The key findings are that expert engineers are critically important to deal with redesigns induced by obsolescence. Moreover, due to barrier uniqueness, long redesign cycles and reliability requirements, conventional knowledge continuity tools are insufficient to enable new engineers to reach expert level. Finally, the thematic analysis shows that, in some cases, outsourcing should be reduced to facilitate internal learning. Originality/value: The study introduces the application of the knowledge-based view of the firm and the concept of requisite knowledge redundancy to the long-term management of complex assets. It calls for more attention to long gaps in the use of unique knowledge and the effect on knowledge continuity.

Sea level rise necessitates the upgrade of coastal flood protection including storm surge barriers. These large movable hydraulic structures are open in normal conditions, but close during a storm surge to prevent coastal floods in bays and estuaries. Barrier improvements lower their susceptibility to operational, structural, or height-related failures. However, there is no method to determine the relative importance of these three barrier failure types. Here, we present a probabilistic method to systematically organize barrier failures and storm conditions to establish exceedance frequencies of extreme water levels behind the barrier. The method is illustrated by an assessment of extreme water level frequencies at Rotterdam (The Netherlands), which is protected by the Maeslant barrier. Four combinations of barrier states and storm conditions were analyzed and prioritized in the following order: (1) an operational failure with 1/100 year storm conditions, (2) a successful closure with an extreme (~1/1000 year) river discharge accumulating behind the barrier, (3) structural failure, and (4) insufficient height both with extreme storm conditions (10^–6 year). The case study confirmed the method's ability to systematically explore promising barrier improvements to adapt to sea level rise, in this case, lowering the susceptibility toward operational failures.

Due to increasing flood risks, storm surge barriers become crucial for the socioeconomic continuity of coastal areas. They provide flood protection, especially against extreme events, by operating under specific circumstances. This imposes high-performance requirements for storm surge barriers and their asset management during their lifetime and emphasises the role and criticality of their asset management. For this purpose, the research investigates asset management for storm surge barriers by focusing on the approach in the Netherlands and analysing it relative to distinctive characteristics of storm surge barriers. Based on thematic analysis, the study unfolds that barriers’ characteristics: (1) clarify the vital motives for the asset management approach, (2) confront the approach with challenging conditions, resulting in further maturation of the approach, and (3) require ongoing support from the approach, enforcing continuous improvement and resilience of the asset management approach. These findings demonstrate the strong influence of barriers’ characteristics on their asset management approach and provide a fundamental understanding of asset management for storm surge barriers. This supports flood defence authorities in the development and improvement of asset management for storm surge barriers and underpins associated complexities for future designs and research. Furthermore, the study assists in tailoring approaches for other assets.

The infrastructure we build is increasingly complicated and automated. After it is designed and constructed, it needs to be maintained and updated to sustain its functioning for far longer than the careers of its designers and builders. Continuity of engineering knowledge is necessary to make future updates and adapt to changing demands, conditions and technology in a safe and reliable manner. The Dutch storm surge barriers protect the low-lying hinterlands from flooding during extreme weather events. Each of the six barriers managed by the Directorate General of Public Works (Rijkswaterstaat) was designed at a different time, to different requirements, and using different types of contracts. This has resulted in six unique structures, some of which use systems and components found nowhere else. In 1997, the Maeslant Storm Surge Barrier was completed, pioneering the use of Design and Construct contracts for major hydraulic structures. Experience with maintaining this hallmark structure through its first decades of operation provides a valuable opportunity to reflect on the effect of contracting- and design choices. Little work has been done to evaluate different contract types on the basis of delivering long-term maintainability and reducing the knowledge continuity challenge. This study views the Maeslant Barrier in the context of the earlier storm surge barriers with regard to facilitating knowledge continuity through design. It was found that the interdependent behaviour of subsystems in a high-reliability structure results in a notable increase in engineering complexity, especially in the control systems, increasing the challenge of achieving knowledge continuity. Examining the knowledge flows in a design-and-construct contract shows several advantages, but also that it does not naturally facilitate attention to important but less obvious aspects of maintainability, such as those related to knowledge continuity.

Storm surge barriers are large movable hydraulic structures which close during a storm surge to prevent coastal floods. In the regions they protect, a failure to close the barrier is often the most likely cause for a catastrophic flood. Nevertheless, flood risk assessments usually only focus on raising flood defences behind the barrier. Despite its importance, there is no general method to assess the costs and benefits of improving the closure reliability. This paper presents a model that optimises investments considering both closure reliability improvements and raising flood defences behind the barrier, using the region protected by the Maeslant barrier as a case. We substantiate that constructing the Maeslant barrier was an optimal economic decision. Moreover, we demonstrate large investments such as a redundant barrier already being economically sound with a few decimetres of sea level rise. Based on our experience with this case study, we expect the model is useful in finding strategies to adapt to rising sea levels and other developments that cause coastal flood risk to rise worldwide.