Designed by the Spanish architect’s Zurich-based firm Calatrava Valls SA, the curving bridge is part of a 13.8-kilometer light rail line now under construction. The bridge’s slender steel pylon, which soars 118 m above one of the city’s busiest intersections, sits adjacent to a future underground train station for the new Jerusalem and Tel Aviv line. A consortium called Citypass has a 28-year build-operate-transfer contract for the project. It includes French firms Alstom and CGEA Connex, and Israel’s Polar Investments, Harel Insurance and local civil engineering firm Ashtrom. “This is a once-in-a-lifetime proj-ect from an engineering standpoint, with unprecedented international involvement,” says Tzachi Strasser, a civil engineer with Israel’s Gadish Group, project manager on behalf of the client, Moriah, Jerusalem’s municipal-owned development firm.

Steel sections are placed at night

But that also includes international controversy. France’s Alstom and CGEA Connex are being sued by a pro-Palestinian group in a French court, who say the line serves Jewish settlers living on land “stolen” from Palestinians. A CityPass spokesman contends that the line will serve all residents of Jerusalem and says the issue of Irish unions refusing to train Israeli rail workers is “very insignificant.”

The bridge is designed to cut an S-shaped curve between Jaffa Road and Herzl Boulevard in Jerusalem. A glass embankment running along the bridge’s eastern side will serve as a pedestrian walkway. “This is the first [cabled-stayed] bridge with a curvature of 90° ever built for use by light rail,” says Dan Ben-Amram, planning manager for Moriah.  “Initially, Calatrava had proposed using welded steel plates to link the vertical and horizontal parts, but we decided to opt for steel casting on the  advice of Cimolai.” Italy-based Cimolai Technology SPA is one of the span’s deck manufacturers on behalf of the contractor, a joint venture of Israel’s Koors Metals and Ramet Ltd.

Cimolai is welding the two deck sections at either end of the bridge. The end sections are 15 m wide, 30 m long and 200 millimeters thick, and are curved to create the bridge’s sinuous profile.

Cimolai also is manufacturing the pylon, located in the middle of the S curve, in 12 sections of about 10 m each.  Each segment is welded on site using steel plate up to 200 mm thick with full penetration welds.

Calatrava's design calls for an asymmetrical pylon and harp-like cables

The bridge sits on concrete supports at either end. These are supported by concrete foundations drilled using the largest micropile available in Israel. Crews drilled some 70 holes, each with a radius of between 60 to 90 centimeters, to depths of 25 m, Ben-Amram says.

Workers are placing 70 cables that give the bridge its harp-like  appearance. Thirty-three are connected to one side of the deck, with an equal number linked to the southern steel concrete support. The four largest cables are connected to the steel pylon’s base to provide balance.  With placement of four to six “strings” per night, officials predict that construction will finish by late August. Then France’s Alstom will lay two parallel slab tracks. Service is set to begin at the end of 2009.

By Neil Sandler