Sea-lock + Lookout Point

IJmuiden Sea-lock

The new sea-lock at IJmuiden is half a kilometer long, as wide as a football field and as deep as a six-storey apartment building. The project cost nearly 900 million euros. The new sea-lock is part of the Rijkswaterstaat program for lock renewals, which also includes the Keersluis Limmel, the third Beatrix Lock, the Terneuzen sea-lock and the Afsluitdijk.


The current Noordersluis (‘Northern Lock’) is forecast to reach the end of its technical lifetime in 2029. However, already, the Lock has become too small for the increasingly larger ships seeking access to Amsterdam Harbour and European ports, from the North Sea. The Amsterdam port region retains strong international appeal and thus, a new, larger sea lock is required to cope with this increased capacity.


The new large sea-lock will be 500 m long, 65 m wide and 18 m deep. The project is in the form of a DBFM tender, and three parties, including the Sluiswachter Consortium (Heijmans - Jan de Nul - John Laing), bid for the contract. The contract for construction of the new sea-lock was awarded, by Rijkswaterstaat, to the OpenIJ Consortium.

The design of the lock and its integration into the landscape, are essential for the spatial quality of the area

The IJmuiden lock complex showcases a rich history of Dutch water management, garnered over 125 years of building locks in this area. Each lock has its own character and represents the specific architecture of an era. The design presented by H+N+S for the new IJmuiden sea-lock adds a new ‘layer’ to this unique history, while also retaining the integrity and feel of the overall ensemble. The design effectively combines the functional, ‘machine’ requirements of the lock, with its role as a key component in the natural landscape.

Integration of control room, hardware and embankment (image ZJA)


Plan design

Given the importance of design and landscaping in conserving the spatial quality of the lock ensemble (both the existing and proposed lock), the tender required the submission of two, separate proposals: an action plan or ‘Design Plan’ (process aspect); and a Preliminary Draft (substantive aspect).

Tasks and responsibilities

The ‘Design Plan’ outlines the crucial importance of spatial quality and design in the construction process and explores how aesthetic quality can be guaranteed. The duties and responsibilities of the landscape architect in the process are acknowledged. The Plan provides clear, practical guidance for the retention of environmental quality in the design of the lock, for controlled building and for the protection of the landscape surrounding the lock.


Integrated design

The overall vision of retaining the spatial quality of the lock area, is broken down into two components in the ‘Design Plan’ – the ‘Machine’ (the lock, lock control building and other lock-related, mechanical constructions); and the ‘Landscape’.

Overarching concept

These two components are then integrated into a comprehensive, technical and functional design. Topics such as ecology, elevation, banks, infrastructure, fencing, signage and furnishings are all meticulously considered.

Flowering vegetation

The ‘landscape’ is a crucial, unifying element of the locks and are, therefore kept as uniform as possible. Grass, trees and shrubs will, through proper management, develop into flowering vegetation. The Plan utilises, where possible, large green ‘units’ or areas.

Solar ramp

At three locations, large green slopes are integrated into the design and wide verges are placed between the roads and bike paths. In two places, the green slopes are made accessible for recreational use, and seating areas are provided to enjoy ‘the lock spectacle’ in a relaxed and green environment.

The solar ramp as a resting point connecting the working areas (ZJA)

XL zebra crossings

In several places, recreational rest areas and picnic areas are provided. These are built on large, concrete bases with wooden seats, bicycle racks, bins and information panels. Extra-large zebra crossings (white thermoplastic) are provided, to ensure the area is safe and accessible for pedestrians.