The U.S. Department of Commerce Building, Washington, District of Columbia

The U.S. Department of Commerce Building was constructed in 1932 at the intersection of 14th Street and Constitution Avenue, NW, spanning three city blocks. The building was renamed the Herbert Clark Hoover Building in 1982 to honor President Hoover, who served as Secretary of Commerce during the 1920s.

All of the twelve arched entrances to the building are enclosed with a set of majestic bronze gates, each of which weigh more than 4,500 lbs. After more than 70 years of continual service, the gates needed major rehabilitation. Conservators from Conservation Solutions, Inc. (CSI) performed a condition assessment which revealed that the twenty-four gates suffered a combination of corrosion and deterioration of the beautiful bronze surfaces and failure of all of the hinge and lock works. Many of the gates were immobile, frozen in place by the advanced level of deterioration of their unique assemblies.

The rigging and transport of the gates presented a formidable challenge owing to new restrictions at the highly secured federal building, the magnitude of the gates and the scope of work. On-site disassembly began with the removal of all shrouds and decorative elements to provide access to the hinges, and that they would not be damaged during the move. The removal of the hinges and bearings required several different processes depending on the condition and design of each group. The rigging of the gates during removal necessitated great care to avoid damaging the metal or surrounding stonework. An eighty-ton crane and nylon web lifting slings were used to hoist the pieces in a manner that did not stress or damage the gates, which were then transported off-site for treatment at CSI’s conservation studio.

Once in the studio, work included washing with water and a conservation detergent to remove surface debris followed by detail cleaning to remove corrosion. Adjustments to the patina were made to tone back the bright green discolorations and to treat areas disturbed by the restoration work. The bronze surfaces were then coated to protect them from further deterioration. Additionally, new bearings and hinges that matched the originals were custom-made then mounted to the gates. All bronze surfaces were patinated and coated to protect them from further deterioration.

The gates were then rewrapped, transported, and reinstalled into their original spaces. The once frozen multi-ton gates now swing with the pressure of a single finger.

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