Comprised of 13,117 tons of hot-dip galvanized steel stringers--up to 66 feet in length, diaphragms, bearing assemblies, and top lateral beams, the Douglas Blue Line elevated structure is a 4.6 mile transportation hub winding its way through the neighborhoods of Chicago. By selecting hot-dip galvanized steel to support the elevated line, the Chicago Transit Authority (CTA) emphasized its commitment to provide uninterrupted transportation service to the riding public. 

The line will experience fewer slow zone areas for maintenance, resulting in less inconvenience to passengers--a primary objective of the CTA as it strives to increase the city's confidence in public transportation. Completed ahead of schedule, the $4.25 million of galvanized steel is expected to save the city millions of dollars over the lifetime of the rail by eliminating maintenance for 50 years or more. Particularly pleasing to CTA and the community is the appeal of the zinc coating and its consistent dark gray color--especially compared of the former structure, which was pock-marked, corroding, and required re-painting every few years. Although this is the first large-scale use of hot-dip galvanized steel by the CTA, it surely won't be the last. The initial cost was competitive, the delivery was ahead of schedule, the aesthetic appeal is terrific, and the long-term savings will be delivered for decades to come.