MAIN DIMENSIONS

The Bridge is one of the largest of its kind. The deck measures 52.3 by 33.1m. When open, the Bridge has a range of more than 63m +NAP. The parallel-shaped fall is unique. The shipping and road traffic crossing under 67.8°. In open position, the fall stands 19m “out of perpendicular”

DESIGN LOADINGS

The design allowed for a traffic class 60, in conformance with the 1963 VOSB, with an increased axis load system equivalent to class 75.

NAVIGATION

The navigation width is 50 metres. The rotating axis was placed further away from the navigation path, with an enlargement of the opening angle to 85°.

STRUCTURAL DESIGN

The Bridge Deck was built in line with most modern steel bridges. The Deck plate, trough-shaped longitudinal girders, cross and main girders form a fully welded, an orthotropic Deck. The rear cross girder supports the main girders at the location of the sideward twist. Girders were constructed from box profiles around the rotation point, where bending and torsion moments are greatest.

Ballast: The weight of the Bascule Bridge was almost entirely balanced by counterweight; the arm of the ballast is short, designed to limit the depth of the bascule cellar; the ballast stands eccentrically in a diagonal direction to compensate for the obliqueness of the bridge.

Rigidity: The square – formed by the two tail girders, the ballast girder and the rear cross girder – provide large rigidity against torsion and bending. The bridge has a 300-mm distortion on the front side, due to its own weight. The distortion caused by its own weight was entirely corrected during fabrication.

THE MAIN ROTATION POINTS
Maintenance-free ball joints were used for the rotation point, with a sliding diameter of 1312 mm. This bearing absorbs the maximum applied radial force of 2000 tonnes. The “loose” bearing is finished with a double sliding layer.

THE MOVING ACTION
The moving time is limited to 120 and 135 seconds, respectively, during opening and closing.

ASSEMBLY
The assembly of the steel structural was geared towards the 120 tonne crane capacity in the assembly hall. The construction was subdivided into twenty-four sections. These sections were then put together in the assembly hall on a pontoon.
Using three pontoon derricks, the bascule bridge has been raised into place and locked in vertical position and the steel ballast placed.

SPECIAL FEATURES
Nominated for the National Steel-Award 1998

DATE COMPLETED

September 1996