The new wooden pedestrian and cycle bridge ZJA designed for the municipality of Harderwijk is the keystone in a series of three bridges connecting the residential areas of Drielanden and Stadsweiden . This new wooden cable-stayed bridge introduces an eyecatcher to the city while crossing highway A28.
The setting and outline
This highway separated the city districts of ‘Drielanden’ and ‘Stadsweiden’ so the Municipality organized a tender to reestablish this connection. The team of builder Heijmans, Timber producer Wijma and ZJA proposed a one off design which not only considered the towns history with the Southern Sea but translated it in a striking design.
The design of this wooden suspension bridge which spans 78-meters resembles two Botters, a type vintage fishing vessel which sailed the former Southern Sea, and is symbol to this former harbour-town. The incorporating of the towns maritime history in the new bridge was clearly expressed by the municipality during the tender fase. This principle has been thoroughly considered by ZJA and then translated into the design. The design of the wooden bridges was engineered in close cooperation with timber firm Wijma from Kampen, a Dutch timber company which - as one of only a few - manages self-sustainable forests in Africa.
The first of the three bridges is a wooden cable-stayed bridge crossing highway 28 with a length of approximately 76 meters and a free span of 50 meters. The second bridge is located in the extension of the first bridge and has a length of approximately 78 meters, distributed in spans of approximately 7.8 meters. The third bridge is a small slab bridge with a span of approximately 10 meters north of both bridges is directly
The design of the cable-stayed bridge is a new icon for Harderwijk. The bridge can be experienced in different ways. For services to the motoring on the A28 passing the bridge a moment of recognition and welcome to Harderwijk. Here are the silhouette and appearance are important. For pedestrians and cyclists are precisely the materials and the issues directly in the eye jumping.
When approaching from the A28, 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 of 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 coloured balustrades.
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 take shape 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.
On January 30, 2015 the project was voted the overall winner of the Dutch FSC (Forest Stewardship Council) -award. The ‘Botterbridge’ was considered an inspiration and eye-catcher with a durable, and public purpose. The application of Azobé FSC wood and how it can be reused also took center stage.
Photo's Botterbrug: John Marshall