Rumblefish—a.k.a. Taylor Yard Bridge

Before Los Angeles was a bustling metropolis, it was a quiet region where the landscape ebbed and flowed with Mother Nature . Floods in the area were not uncommon, however, the area’s first residents, Native Americans, moved with the water. As the city began to industrialize at the turn of the 19th century, more permanent developments—homes, industry, and railroads—were erected near the river and the same floods, once incidental, were now a real threat to both life and property.

In 1938, Los Angeles was besieged by two storm systems delivering record-breaking rainfalls . The Los Angeles River had become completely warped, flooding roughly one-third of the city 2. This catastrophe prompted the total channelization of 51 miles of the river, turning the once wild waterway into a flood control conduit and, inadvertently, a de facto wall. This fortification would for decades impact the city both economically and culturally, reinforcing borders between communities that had already been cordoned by railroads, industry, and freeways. Any evidence of vegetation was, too, completely desecrated or packed beneath 3.5 million barrels of cement and 147 million pounds of reinforced steel.

Rumblefish, as we’ve dubbed the bright orange bridge, playfully takes its name after the 1983 Coppola film about rival gangs, while similarly referencing the actual gangs that once battled in the area. Our design of the bridge counters this violent past—and nullifies the river’s past as a border wall—by offering a meeting point in the middle where two outcroppings looking north and south, up and down the river. The center of the bridge becomes a place for community collision—of the peaceful kind—as well as contemplation of the river. It was also important for us that the bridge be able to accommodate small community events and outdoor exhibits.

The architecture of the bridge is uncomplicated, akin to an oversized box truss that slopes from east down to west. The form takes inspiration from the area’s industrial past, a modern interpretation of the railroad bridges that once crossed the river, and the mid-20^th century Los Angeles Case Study Houses. The path connecting both sides of the river has been designed to “float” within the truss structure. This path slopes to meet the different elevations of the banks while the truss is completely level. This track is an extension of the roads and walkways on terra firma and is a representation of the city’s paths as it passes over the bridge—the truss is there to simply hold this path in place.

In construction, we engineered Rumblefish to employ the lightest structural elements possible: tube steel, wide flange steel, and steel rods. HSS steel members form rectangular openings, and the bracing of the frame is achieved by the provision of cables spanning diagonally in vertical planes. This hybrid frame has rigid joints that are capable of transferring and resisting bending moments, and diagonals working in tension only.

The bridge will be built using a redundancy system that will enable the structure to carry loads after failure of one or more components. The use of this hybrid form allows the vertical planes in the bridge to remain almost unobstructed and provides for open viewing of the LA River along the bridge length.

During construction, pieces will be componentized so that larger portions of the bridge can be assembled in an adjacent yard and work within the riverbed can be minimized.

Site work on Rumblefish begins the summer 2018 and the bridge is anticipated to open to the public the second half of 2020.