Mt. Vernon Avenue Bridge taking shape with placement of 182-foot support beams, the longest in California
September 6, 2024
Construction progress on the Mt. Vernon Avenue Bridge over the Burlington Northern Santa Fe (BNSF) railyard in the city of San Bernardino took a visibly giant step forward this week with the placement of two support beams measuring roughly 182 feet long. The beams, also called girders, are the longest precast girders made for a bridge in California.
The girders weigh more than 250,000 pounds each. Due to their size, the girders required special transport from Lathrop in Northern California via two specialized 9-axle semi-trucks and an escort by the California Highway Patrol.
Additional girders of similar length will be delivered in the same manner in the coming weeks. To facilitate placement and installation of the girders, which support the bridge’s driving surface, two large cranes were used to simultaneously hoist each girder into place in the overnight hours.
In total, nine 182-foot-long girders and another 44 girders, each measuring between 90 feet and 180 feet long, will be installed to complete the support portion of the bridge’s driving surface. Girder placement is expected to be complete this fall.
The girders are precast and pretensioned, made by pouring concrete around steel cables under tension. This type of girder is preferred for projects that have long spans, like the Mt. Vernon Avenue Bridge, because they provide reliability, structural consistency and allow the bridge to be built quicker.
As the remaining girders are installed, residents, visitors, students and businesses will see the bridge taking shape, signaling major progress on the bridge’s reconstruction.
Construction efforts on the new bridge resumed in October 2023 following a pause to allow BNSF time to make improvements and construction accommodations within the railyard. In May 2024, a segment of the new bridge over 3rd Street saw the installation of eight girders that were each roughly 64 feet long.
When complete, the Mt. Vernon Avenue Bridge will pass over 22 active railroad tracks and measure more than a quarter mile long, spanning the entire north-to-south width of the BNSF Intermodal facility in San Bernardino, one of the largest railyards in the region.
The original Mt. Vernon Avenue Bridge opened in 1934 and quickly became an iconic structure, bridging westside San Bernardino communities to the north and south and serving as a vital link for residents, visitors, students and businesses.
To ensure the safety and longevity of the bridge, the city of San Bernardino and the California Department of Transportation (Caltrans) partnered with SBCTA to rebuild the
bridge.
The bridge closed in December 2020 and disassembly was completed in April 2021.
The bridge is expected to reopen in summer 2025 with wider lanes and sidewalks, bike lanes and a center median, as well as artistic elements giving a nod to the original bridge’s historic design.
Find more information on the Mt. Vernon Avenue bridge construction here.
Find a link to download photos here.
