Bridge design options taking shapeWhen the Minnesota Department of Transportation narrowed the number of remaining design options for the new Highway 61 bridge to two, arch and cable, it didn’t get any more specific than that.
By: Keith Grauman, The Hastings Star-Gazette
When the Minnesota Department of Transportation narrowed the number of remaining design options for the new Highway 61 bridge to two, arch and cable, it didn’t get any more specific than that.
Now, however, the Visual Quality Team, which has been meeting for about a year to discuss the aesthetics of everything involved with the project, has come up with recommendations for how the bridges themselves will look, and those recommendations will be part of the request for proposals that MnDOT will release in late November.
MnDOT is including both bridge types in the request for proposals in hopes that it will lead to more competitive bidding from contractors, and thus, a lower overall cost for the project.
The Visual Quality Team’s recommendation for the arch bridge is what’s called a “basket handle” design. Where the arches on the current bridge run parallel to one another in straight lines, the basket handle design has both arches sloping inward toward each other as they get higher, and coming together to touch at the peak of the arch. The exact design could change slightly as design-build contractors tweak it.
The Visual Quality Team also came up with a recommendation for the design of the towers on the cable bridge. From the river to the top of the towers, they’d be shaped like thin diamonds, with the widest part where the bridge deck is located, getting thinner from the road to the top of the tower, and from the road down to the river.
Both bridge types also include two pedestrian overlooks on the sidewalk on the bridge, which will be located on the east or northbound side. The overlooks would be semi-circles where walkers or bikers could pull off the sidewalk. The exact location of the overlooks hasn’t been decided, but the Visual Quality Team recommended one be above the river and one be closer to downtown.
Both the cable and arch bridges are single spans, not twin bridges as was proposed for the eliminated girder bridge option. But, another recommendation from the Visual Quality Team that’s being worked into the plans is to separate the spans from about the south bank of the river to Third Street, which will let natural light filter down to Second Street. The new bridge will, after all, be more than twice as wide as the existing bridge, which could mean dark, shaded areas under the bridge.