Neeltje Jans Radartower

A beacon project in Zeeland

Neeltje Jans, an artificial island in the Oosterschelde, is renowned for Deltapark, a leisure destination that celebrates the Delta Works - the Netherlands’ most iconic engineering achievement. Since 2015, the island has welcomed a new landmark: a 115-metre radar tower with an impressive 40-kilometre range, enhancing maritime safety in one of Europe’s busiest waterways.

Project overview

Rising on a mole extending 1.5 kilometres into the sea near the Oosterschelde storm surge barrier, the Neeltje Jans radar tower rises above the Scheldt. This tower, a high-tech structure, was added to the Belgian-Dutch radar network and provides real-time tracking of maritime traffic up to 40 kilometres away. Its strategic location and advanced design make it a vital asset for navigation and safety in the region.

The tower’s design prioritizes structural rigidity to ensure a stable radar image, even under extreme weather conditions. Wind tunnel tests on a 1/75 scale model recorded wind speeds of up to 250 km/h around the tower’s head. To mitigate turbulence and extend the radar’s operational life, the antenna is positioned in a calm zone, nine metres above the roof.

Scope of works

Construction of a 115-metre-high concrete radar tower using climbing formwork
Integration of vertical post-tensioned cables up to mid-height for enhanced rigidity
Use of high-performance concrete mix C53/65 for increased elasticity and 100-year design life
Implementation of a 3D BIM model to streamline design and construction phases
Wind tunnel testing and environmental analysis to optimize radar placement
Installation of radar systems with strict angular displacement and torsion tolerances

Highlights

Record radar range: Capable of tracking vessels up to 40 km away
Engineering excellence: Designed to withstand wind speeds of 250 km/h
Longevity: Built for a functional lifespan of 100 years
Precision design: BIM integration allowed early detection and resolution of design issues
Strategic location: Enhances maritime safety in a critical shipping corridor

The antenna is the crucial part of a radar system and must remain operational under all environmental conditions. To limit deviations of the radar signals, extremely strict requirements were applied to the design in terms of angular displacement and torsion. That is why we have paid particular attention to the rigidity of this slim tower. Vertical post-tensioned cables equipped this slim tower until mid-height. The concrete mix C53 / 65 is specially designed to ensure an increased modulus of elasticity and a functional design life of 100 years.