One notable recent instance where a long-span truss design was considered was the Columbia River Crossing, a joint effort by the states of Oregon and Washington to replace the pair of existing through-truss bridges that carry Interstate 5 over the Columbia River. Beginning in 2005, the states engaged firms to plan a new, higher-capacity bridge that also would carry a light-rail line. A double-deck truss design was specified. But disputes occurred over long-range traffic projections and toll-revenue forecasts, and, in 2013, the Washington state Senate failed to approve funding, thus ending the project.

One of the projects we feature above is a steel through-truss bridge whose construction was extensively documented in ENR more than 50 years ago. The Astoria-Megler Bridge spans the Columbia River between Astoria, Ore., and Megler, Wash. Completed in 1966, the 376-m main-span bridge rests on a sandy riverbed, which presented a foundation problem that required driving 200-ft-long steel piles. 

DeLong Corp. constructed the bridge’s 32 piers, which involved the casting of pier shells of up to 377 tons and cap beams as heavy as 830 tons. The project marked the debut of “rotobags,” or two-compartment, 1½-cu-yd-capacity rubber bags that held aggregate and water in an outer compartment and cement in an inner, dry compartment for storage and transport from the batch plant and the mixers. 

Developed by Rodeffer Industries, the bags did for concrete handling what instant cake mixes did for baking, making ready-mix trucks unnecessary and significantly reducing batching costs. DeLong crews prefabricated the pier shells and caps on the decks of barges that were moored adjacent to the concrete batch plant. 

DeLong’s general superintendent was killed when a broken cable knocked him into the river. Pomeroy & Gerwick Co. built the concrete roadway connecting the spans. The American Bridge Division of U.S. Steel Corp. built the bridge’s steel superstructure, and the truss segments were fabricated in Vancouver, Wash., 145 km upriver, then barged downstream and lifted into place with hydraulic jacks. The construction cost was $24 million (ENR 10/17/63 p.28).