Renovation of the Zeedok lock

The Zeedoksluis complex dates from 1974 and is located between the seaport of Den Helder and the Willemsoord basin. The lock complex comprises a navigation lock, a bascule bridge and a lifting bridge. The navigation lock is a sea lock and forms part of the primary flood defence system.

The lock complex has not undergone any major renovation since it was built. It was found that the technical condition of the complex was compromising the operational reliability of the lock, meaning that the lockage function could no longer be guaranteed. In addition, the lock was not suitable for safe use by shipping. Port of Den Helder (PoDH) therefore decided to renovate the lock complex.

In collaboration with PoDH, Iv has been involved in every phase of the renovation project. The project began with the necessary surveys, technical inspections and investigations. Various options were then assessed, and Iv advised on the renovation scope, after which the contract documents were prepared in accordance with UAV-GC 2005. Iv also supported the tendering process and, during the subsequent design and construction phases, supervised the contractor’s work using Systems-Oriented Contract Management (SCM).

The starting point for the project was an asset data dossier that was neither complete nor up to date. To gain a clear understanding of the technical maintenance condition of the various assets within the lock complex, Iv carried out an archive analysis and extensive technical inspections. These showed that almost every part of the lock complex required intervention, ranging from replacement of the entire electrical installation, operating and control system and mechanical installations to improvement and repair works on the civil structures and site areas. Occupational health and safety and machine safety also had to be improved. A truly multidisciplinary assignment.

In collaboration with PoDH and the stakeholders involved in the lock complex, the requirements and preferences for the renovation were identified, renovation and replacement options were considered and assessed, and the renovation scope was defined. This scope was then translated into a renovation contract under UAV-GC.

A particularly notable aspect of the project is that a system was developed which allows the lock, as part of the primary flood defence system, to remain fully open during operating hours in the summer months and to facilitate the smooth passage of waterway traffic, while still being capable of being closed safely.

Iv’s work contributed to a fully upgraded lock complex that can be used safely and efficiently by both shipping and road traffic. The reliability and availability of the complex are guaranteed for the next 25 years, the operability of the lock has been improved, and management and maintenance requirements have been reduced to a minimum.