Downtown Milwaukee—one of the oldest sections of the city had little pedestrian traffic after dark. The historic area includes a mix of businesses and residences, and features a variety of architectural styles, with many of the building facades adorned with brick.
During a recent renovation, city officials took the approach that people would come downtown if the area was provided with ample lighting. Because officials wanted to emphasize the city's heritage, lighting fixtures had to create a historical feel that would complement the areas architectural styles.
As part of the renovation, modern-looking canister-type fixtures that were installed during the 1970s were replaced with Milwaukee Harp street lights from Holophane Lighting. The fixtures are installed along Wisconsin Avenue-the main thoroughfare- and use 100 watt high-pressure sodium lamps.
According to Bob Rehm, street lighting engineer for the city of Milwaukee, the Holophane fixtures replicate street lights with the same name that originated in Milwaukee in 1903. Early in this century, thousands of the harp-shaped Milwaukee Harp fixtures illuminated the city's streets.
"The current Milwaukee Harp street lights are based on the original design with updated, state-of-the-art optics. We chose the Holophane harp fixtures because they have the best photo metrics and provide the lighting uniformity that is needed on the street," Rehm explained.
Fixtures are mounted on 15-foot octagonal steel posts placed two to three feet behind the curb. Spacing ranges from 60 to 90 feet—depending upon the location—with illumination levels at 2 foot candles average maintained.
Holophane's Computer Aided Lighting Analysis (CALA) software was used during the design process to determine lamp wattage, fixture distribution and light levels. Even though the fixtures are 15 feet above the ground, the Milwaukee Harp street lights bring the light center up to 17 feet, resulting in wider light distribution. The units have IES cutoff so light trespass is not a problem.
Rehm indicated one of the challenges associated with this project was the hollow sidewalks resulting from utility tunnels and older building basements that extend beneath the walkways. Because the sidewalks could not support new concrete bases, installing high level poles was not an option.
"With the Milwaukee Harp fixtures, we could properly illuminate the street with the street lights mounted on lower poles. In most instances, we were able to install the fixtures on existing bolt circles using the same wiring, which significantly reduced the installation costs," Rehm said.
The Milwaukee Harp fixtures with 150-watt high-pressure sodium lamps also surround Milwaukee's new Midwest Express Convention Center. Fixtures are spaced 40 to 45 feet, with illumination levels of 4 foot candles.
"We like the fact that we were able to bring these historic lighting fixtures back to Milwaukee" Rehm said. Since the area was renovated, we have seen a significant increase in pedestrian traffic and more businesses and housing are moving downtown."
A central electronic eye controls street lights along the street and around the convention center, with the units illuminated about 93 hours each week. The fixtures will be group relamped approximately every four years. Electronic components are located in the bottom of the Milwaukee Harp fixtures to facilitate maintenance.
Besides the harp street lights, the city of Milwaukee will install Holophane lantern fixtures at intersections in the downtown area.