by Michael R. Allen
The new Grand Avenue viaduct over the Mill Creek Valley will be a decent and well-built piece of infrastructure. Replacing a streamlined structure from 1959, the new viaduct skips over its mid-century predecessor to appropriate elements of the original Grand Avenue viaduct. Or does it?
The Grand Avenue viaduct was completed in 1891 as a true suspension bridge. Its piers were of solid masonry, its towers were strong metal and its metal bars carried the weight of the bridge deck.Â In short, everythingÂ that gave the bridge grace and form was a matter of necessity instead of affectation.Â The beauty of such a bridge lies in the seamless marriage of engineering and architectural design.
By comparison, the new Grand Avenue viaduct affects a nostalgic image by placing anemic, open work towers at certain intervals and cladding parts of its base in false rusticated limestone. The homage to the 1891 structure seems strange for a modern truss bridge, which of course has its own very intriguing structural form hidden under the trappings of style. The new viaduct will be a decent attempt at falsely historic detail, like Busch Stadium or countless urban infill houses with wooden cornices and brick veneers. However it will not match either of its predecessors in plainly and gracefully exhibiting its true form or its actual materiality. The elegant expression of a structure’s true form and material is the origin of greatness in design.