Currently, crews are placing the final touches on the Wasco Viaduct. Along the pergola section, crews have worked to complete the parapets – or derailment walls – of the structure. More than 240,000 pounds of steel and 800 cubic yards of concrete were installed in the last few months. Crews also completed the installation of the expansion joints of the structure. Expansion joints are separations between two sections that allow for temperature-induced expansion or contraction without cracking or damaging the structure. The Wasco Viaduct is more than 2,000 feet long and carries trains through Kern County and over the BNSF freight tracks.