Building as Icon

The past weekend saw the official opening of the new Margaret Hunt Hill Bridge in Downtown Dallas, Santiago Calatrava's first vehicular bridge in the United States. Named after civic leader and first-born daughter of Texas oil magnate, H.L. Hunt, Jr., the bridge is the first realization in a series of new architectural developments in Dallas, as part of the USD 2,2 billion Downtown Dallas 360 plan.

Spanning the Trinity River, the Margaret Hunt Hill Bridge connects Downtown to West Dallas, and aims to reconnect the city with its outer boroughs. Construction began in July 2007, but the plan for the bridge dates back to the late 1990s, when city officials first saw the need to promote an alternate route of transportation from downtown area to West Dallas. Calatrava was selected by the city at the suggestion of Texas-based architecture firm Halff & Associates.

Dedicating much of his early practice to bridge and train design, Calatrava's focus on connectivity through engineering and design has become a leitmotif throughout his career. This bridge is a formal culmination of a series of previous projects including a design for the atrium of Allen Lambert Galleria at Brookfield Place in Toronto, Canada (1992); the L'Umbracle parking structure at the Ciutat de les Arts i les Ciències in Valencia, Spain (1996); and most recently his three bridges project in Reggio Emilia, which all use a similar vernacular, modified and articulated throughout the years.

The Margaret Hunt Hill Bridge's design is most obviously evocative of Eero Saarinen's famed engineering feat — the Gateway Arch in St. Louis. While Saarinen's footprint is heavier-handed, Calatrava's curvilinear form is lighter in gesture and form. Like St. Louis' Arch, which was built as a monument to westward expansion, the Margaret Hunt Hill Bridge was built as a connector to encourage development and expansion into satellite neighborhoods of the city.

The suspension bridge includes 58 different sized cables (ranging from 10 to 20 centimetres in diameter) attached to the steel arch and the center of the roadbed, creating a physical connection between the arch and the land to which it is anchored. Steel components were fabricated in Italy by Cimolai, where the 570-metre long, 36-metre wide, 120-metre tall arch was first assembled, to make sure each piece was an exact fit and weight combination. The arch was then shipped to Texas.

This is the first of three planned bridges by Calatrava for the city of Dallas. Currently in development is a pedestrian walkway and plaza, which will further connect West Dallas to the burgeoning Design District in Downtown. The Downtown Dallas 360 plan also includes projects by Thomas Phifer and Thom Mayne's Morphosis, adding to the city's built landmarks by I.M. Pei, Renzo Piano, Norman Foster, and Rem Koolhaas. Danielle Rago (@danielle_rago)