First off, let me just say- you’ll never hear me speak badly of the helical form. I think it is a geometry that resonates especially strong with us humans. Why? I don’t know, it certainly hasn’t just been a fad since Watson, Crick, and Franklin’s work. It must be something to do with its self-similarity and intertwined simple complexity. Due to this geometry, the helix is a rather stable structure as long as it is braced to another (or in the case of this bridge, three other helices). The Helixxx Bridge, designed by Eugenio Aglietti takes the archetypically subtle arch of conventional bridges and marries it with the self-centering geometry of the helix to span the Amstel River in front of the Amsterdam Hermitage Museum.
Already an extraordinarily organic form, the helix is ignited one might say, by its slight curvature. There is no longer any clear or perfectly framed view- this becomes an amalgam of bridge, view of and away from the museum and travelers. However, here is my critique. There is no cross bracing. Geometry alone won’t do it! The helices are braced together by what can be simply considered as parallel connectors. What is there to resist one helix from being acted on by a unmitigated force, forcing it to slip past the others and destroying the unity? Nothing. There has to be something which can’t be stretched or compressed. Cross bracing.
The four helices are enclosed to by glass and perforated ceramic panels. These provide views up and down the river while allowing airflow and creating a microclimate of sorts withing the volume of this bridge for pedestrians.