News

Wooden cable-stayed bridge, Harderwijk.

11.12.2014

On December 11th the new wooden cable-stayed bridge at Harderwijk (NL) was officially unveiled to the public. The bridge crosses highway A28 and connects the City centre with its neighbouring town-district ‘ Drielanden ‘.

 

The cycling route

The new cable-stayed bridge is part of series of bridges along a new bicycle route designed by ZJA. This route crosses Highway 28 and connects the already present Northern and Southern Sea path-routes which were cut off.

The northern Sea path runs along the former Zuiderzee, all the way to the centre of Harderwijk and the old fishing harbour, where even today some “Botters” -old fishing vessels- are moored. In the design-brief this “ Botter “ and its historic relation with the city of Harderwijk was essential for the design. This principle has been thoroughly considered by ZJA and then translated into the design. The wooden bridges were designed in close collaboration with timber firm Wijma from Kampen, a Dutch timber company which -as one of only a few- manages self-sustainable forests in Africa.

 

The bridges

The first of the three bridges is a wooden cable-stayed bridge over the A28 with a length of 78 meters and a free span of 50 meters. The second bridge is located in line with the first bridge and has a length of 78 meters, spanning in segments of 7.8 meters. The third bridge is a small slab-bridge with a span of 10 meters, located immediately north of the two other bridges.

The design of the cable-stayed bridge is a new icon for Harderwijk. Encountering the bridge over Highway 28 should result in a moment of recognition for the motorists, a welcome to Harderwijk.

It offers two distinctive experiences:

Firstly the experience at speed as seen from the motorway the main elements as the wooden pylons and cables will shape the silhouette. Secondly while on the bridge by foot or bicycle the smaller scale, details and materialization can be experienced.

 

The silhouette

When approaching from highway 28, the silhouette of the bridge is strongly associated with the silhouette of a ‘Botter’, with its asymmetric sail and rigging distribution and the characteristic slightly sloping wooden mast. The main structure of the bridge is constructed from Azobé, a wood typical to engineering and marine applications. The wooden deck is suspended by cables, hanging from two massive wooden pylons, depicting two ‘Botters’, with the wooden deck line sharply contrasting against the lighter steel balustrades.

 

Material selection

Maintenance-free and "aging gracefully" are central to the future value and sustainability of the three bridges. The materials have been chosen in such a way that the bridge will look better with age and that inevitable minor damages are included in the bridge in a natural manner, and do not disrupt as scars. As a result of weathering, the wood used will only turn better. Besides that, the preserved steel railing will remain unchanged, unaffected by the elements and so form a more beautiful contrast with the wooden deck.    

 

Project: 745

Photography: ©Ton Pors