Below the busy streets of downtown Oklahoma City sprawls a vast network of tunnels and bridges that links 16 blocks and more than 30 of the area's buildings. Formerly dubbed the Conncourse in honor of Oklahoma City banker Jack Conn, this 3,000-linear-foot passageway experienced its heyday in the 1980s. However, a recent $2 million facelift to what has been re-christened “the Underground” has helped make this locale a popular downtown attraction once again.

The city's first tunnel was dug in 1931, but the bulk of construction took place between 1972 and 1974. Thirty-plus years later, the system called for a complete modernization. According to Elliot + Associates Architects, Oklahoma City, the architect firm that developed the redesign plan, the goal of renovating the tunnel system was to improve its quality and public perception.

In addition to fresh paint, new carpet, updated signage, and a new gallery-style display of historic Oklahoma City photographs, a major lighting upgrade was integral to the project's success. Tulsa-based Oil Capital Electric, the electrical contracting firm that performed the lighting installation, began work on July 5, 2006, and finished a little more than six months later. Jeff Griffin, project manager for Oil Capital Electric, says strip lights and can lights are the two types of luminaires that predominate the retrofit.

What makes this project unique, however, is the use of colored lighting to denote different areas of the tunnels. For example, green lights illuminate the passages connecting banks while blue marks those tunnels that link to federal buildings.

“This upgrade brought identity to the Underground and also provided a ‘mapping’ for people using the system by incorporating colored lighting, which was achieved through the use of colored lamp guards and strip lights,” says Griffin.

One challenge faced by the contractor was the requirement that the tunnels remain open during construction.

“People downtown are used to getting from banks to the courthouse to office buildings without having to traverse the street outside, particularly in inclement weather,” says Griffin. “Also, businesses in the Underground can only be accessed using this walking area under the city, so it had to stay open. Because you cannot turn off lights in a tunnel system, we had to keep areas lit while changing to the new installation.”

On November 29, Interior Design magazine announced it had chosen the Underground as the winner of the Public Spaces category in its 2nd annual Best of Year Awards.

“The opportunity to use colored lights to illuminate an underground tunnel system doesn't come along too often,” says Don Beach, senior manager for Oil Capital Electric. “We were glad to be a part of this unique project.”

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