Tagus River Bridge – Road Deck

Completed in 1966 by American Bridge, the Tagus River Bridge – Road Deck project consisted of the financing, design, and construction of a 10,573′ (3,223m) crossing of the Tagus River near its mouth at the Atlantic Ocean. The project included a 14-span, 3,100′ (945m) cast-in-place concrete viaduct over Lisbon’s Alcantara District and a six-span, 7,474′ (2,278m) steel truss bridge over the river. Undertaken by a consortium led by USSI (a United States Steel unit that included American Bridge), the viaduct was designed by Tudor Engineering and built by SOPOL. American Bridge and Morrison Knudsen handled the steel bridge, with MK responsible for foundations and anchorages, and American Bridge for the superstructure. The steel design was subcontracted to Steinman (now Parsons). The six-span continuous truss (7,466’ / 2,276m) included a 3,323’ (1,013m) mainspan and three backstay spans of 324’ (99m). The 588’ (179m) towers, cable bents, and anchorage steelwork (15,822 tons) were fabricated at American Bridge’s Ambridge Plant. Saddles were made by Blaw-Knox; cable bands by U.S. Steel Johnstown; and 9,880 tons of wire and cable by U.S. Steel’s Wire Division. Stiffening and floorbeam trusses (13,741 tons) were fabricated by SOREFAME; truss cross bracing (2,510 tons) by American Bridge’s Trenton, NJ plant. Total structural steel weight was 52,422 tons (47,556mt). All steel and cables were erected by American Bridge. Suspended span trusses were preassembled on a 16-acre site in Lisbon and floated into position, while backstay trusses were erected in place with stiffleg travelers. The project duration from start to opening was 1,988 days (65½ months), with 1,370 days (45 months) of field construction.