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.

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.