The floating Ravelijn Bridge in the Netherlands
RO&AD Architecten used Accoya® to create this spectacular "floating" bridge in the Dutch city of Bergen op Zoom. This 80-meter-long pedestrian bridge crosses over the Pielekenswater and was inspired by the work of Dutch military engineer Menno van Coehoorn.
Located in the city of Bergen op Zoom in Middelburg, The Netherlands, the Ravelijn Bridge’s sweeping length has a unique curvature and natural elegance. Ro Koster and Ad Kil of RO&AD Architects designed the bridge, and these brilliant architects just happen to be the team behind the famous and award-winning Moses Bridge in Halsteren.
Both the Moses Bridge and the Ravelijn Bridge pay homage to the remarkable qualities of Accoya® ®, a premium engineered timber which is quickly becoming the building material of choice across the globe. In simple terms, they are no different to ordinary bridges in the sense that they create a path from one place to another. But through their design, they are proof that architecture can lead the way when it comes to protecting the environment. The bridges are minimal in terms of their structure and yet captivating at the same time, and perfectly honour the heritage and history of the local area.
Celebrating the history of the Ravelijn
The Ravelijn “Op den Zoom” is a fortress-island near the city of Bergen op Zoom in The Netherlands. The island was made at the beginning of the 18th century by Menno van Coehoorn, a famous fortress builder of the period, but now the Ravelijn is the only evidence of his work that remains.
Towards the end of the 19th century, the fortress stopped being used as a defensive asset and in 1930, developers added a raised wooden bridge. Fast-forward to today, the fortress is now mainly for small public and private events. In 2013, Ro Koster and Ad Kil were tasked to design a second pedestrian bridge which would connect the fortress to the city centre but would also act as a second escape route in case of emergencies. In March 2014, the new bridge was completed.
Creating connections between pedestrians and the past
The fortress was only accessible by boat, so supplies and soldiers had to be rowed back and forth across 80 meters of water. If you look closely, you’ll see original entrance where the boats would row to, just visible above the waterline. The floating bridge follows the original track of these boats, echoing the weaving, curved route the ships followed from the city to the fortress. In winter, the city can pull the bridge to the side, so there can be ice-skating around the fortress.
The shape of the decking is convex, helping the bridge to blend with the water as much as possible. What’s more, this design avoids any mirrored reflections of the bridge on the water’s surface. The jetty stairs near the fortress can move up and down (or stay horizontal) depending on the water level.
Sustainability at the forefront of design
The Ravelijn bridge is made entirely to the principles of the Cradle to Cradle philosophy. Air-filled polyethylene pipes positioned underneath the timber surface help keep the bridge afloat, without requiring any additional structural framework. Accoya® was the natural choice for the structure. Most timber materials would quickly deteriorate from rot and fungal decay, and swell and shrink due to its proximity to water. Accoya®, however, has exceptional durability and will guarantee the bridge can be enjoyed for years to come.
Why we use Accoya®, the ultimate sustainable timber
Accoya® primarily comes from abundantly available, FSC-certified, fast-growing trees such as Radiata Pine. The trees are sustainably sourced from forests in New Zealand, Chile, or Spain. Radiata Pine is an environmentally friendly alternative as it takes approximately 28 years to grow, compared to 70-120 years for a hardwood alternative such as oak. It is one of the very few building products to have acquired Cradle-to-Cradle certification at the stringent Gold level. Accoya® is CO² neutral throughout its full lifecycle, 100% biodegradable and offers exceptional performance and longevity. When the time comes to dismantle the bridge in the future, the decking can be disassembled and recycled sustainably.
At Westbury Windows & Joinery, we use Accoya® for the outward-facing section of our engineered wood, particularly for vulnerable elements of our projects such as the ridge cap of a roof lantern or the external window cill. We also use Tricoya® (a version of MDF made from Accoya®) to manufacture our door panels. Accoya® provides superior thermal insulation and is guaranteed to last for up to 50 years, making it an excellent material for our bespoke doors, windows, and roof lanterns.
Westbury Windows and Joinery produce exceptional bespoke windows, doors and roof lanterns. Contact us today to discuss your project in more detail, or alternatively you can book an appointment to visit one of our showrooms.
All Images by Erik Stekelenburg