Bridge of the Americas: the Balboa road crossing opens in 1962

The Panama Canal allowed oceangoing vessels to cross the isthmus while separating road traffic between its banks. The Bridge of the Americas crosses the channel near Balboa at the Pacific entrance; contemporary United States canal documents called it Thatcher Ferry Bridge. Vehicles had previously used the Thatcher ferry, operating for about thirty years, and the swing bridge at Miraflores Locks. Built to serve the third-locks project, the latter could not replace a continuously open high-level crossing.

The 1955 agreement between Panama and the United States again included a bridge at Balboa among the United States’ commitments. In 1956, Congress appropriated $20 million for design and construction. The project had to accommodate two intersecting transport routes: free passage for vehicles and pedestrians above, and continued navigation by oceangoing ships below. Shipping requirements therefore governed the high bridge’s clearance.

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Sverdrup & Parcel and Associates of St. Louis designed the bridge, supported by a canal-agency advisory group that included structural, geological and architectural specialists. On December 23, 1958, Panamanian President Ernesto de la Guardia and Canal Zone Governor William Potter attended the groundbreaking at the foot of Farfan Hill. Substructure construction began in September 1959, with dredges first opening channels for workboats to reach the piers.

A joint venture of Fruin-Colnon International and LeBoeuf and Dougherty received the substructure contract. In February 1960, John F. Beasley Construction Company of Dallas obtained the $9.199 million superstructure contract, including steel components produced jointly by four West German companies. Other contractors built the approaches, paving and connecting streets on the Panama City side.

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The three principal spans form a cantilever and tied-arch combination. The approach spans combine deck cantilevers and simple spans. Resident engineer Elmer Stevens explained that the central tied arch joins the cantilevers on either side, forming what engineers call a suspended span. This steel truss system carries the loads over the main channel.

Contemporary engineering accounts give the bridge’s length between abutments as 5,425 feet, approximately 1,654 meters, across fourteen spans. The main span over the channel measures 1,128 feet, about 344 meters, with 201 feet, or about 61 meters, of clearance above mean high water. The main bridge has four traffic lanes and the approaches three, with four-foot sidewalks. A seven-inch reinforced-concrete deck rests on the steel beam system, transferring road loads through the superstructure to the piers.

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The water piers needed foundations on solid rock. Single-wall cofferdams with internal bracing enclosed work areas for excavation and concrete placement under relatively dry conditions. Construction of the two largest cofferdams encountered difficulties. On land, groups of cylindrical reinforced-concrete caissons transmitted loads to rock; the abutments were also reinforced concrete.

The last substructure concrete was placed on October 25, 1961, and the substructure was completed on November 4. Its rock-founded bases and piers provided the supports and capacity needed for subsequent cantilever erection. Construction also had to accommodate canal operations, with vessels and lifting equipment delivering concrete and steel to the pier locations.

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Steel components began arriving from West Germany in June and July 1961. That August, seventy-five specially trained steelworkers came from the United States to assemble the spans with bolted connections. In early March 1962, a floating crane lifted a ninety-eight-ton component: the project’s heaviest planned single-piece lift and an important initial component of the central tied-arch span.

On May 16, 1962, the floating crane raised a seventy-foot steel beam into the middle of the bridge, connecting the structures extending from the two banks. Concrete paving, lighting, painting and approaches still required completion after the spans met. On the evening of September 8, deck lights and aircraft-warning lights came on together as the project moved toward preparations for opening.

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The inauguration took place on October 12, 1962, with Maurice Thatcher cutting the ribbon. Photographs in the following month’s official publication recorded the ceremony and Pelican State passing beneath the bridge afterward. As the fixed crossing entered service, the ferry President Roosevelt was withdrawn from its former route and moved to Gamboa. Vehicles no longer had to use that ferry route to cross the canal.

Pre-opening figures put combined traffic on the ferries and Miraflores movable bridge at about 8,200 vehicles daily. Approximately 2,300 traveled between Panama City and the interior, with the remainder mostly moving between areas on either side of the canal. The new bridge served long-distance roads and reorganized local commuting and freight. Officials forecast 10,700 daily bridge crossings for the following year; the publication presented that number as a prediction made before opening.

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