In January 1998, Chicago's mayor, Richard M. Daley, returned from a trip to Paris brimming with inspiration. After viewing the lovely architectural lighting in that city, Daley told the newspapers that he wanted to illuminate the downtown area of his city.
Enter Tracey Dear of Dear Productions. The LD was working as head of the lighting department of the House of Blues in Chicago, but was looking for a change from the music industry. He made some calls, and eventually ended up on the phone with the Cultural Office. "They asked me if I could light bridges, and I said, 'Why not?' " That simple answer propelled him into a $1.8 million project that culminated in Chicago's Downtown Lighting Master Plan.
The project encompasses 11 bridges--Lake Street, Franklin Street, Wells Street, LaSalle Street, Clark Street, Dearborn Street, State Street, Wabash Avenue, Michigan Avenue, Columbus Drive, and Lake Shore Drive. The bridges cover an area of 1.2mi. (1.9km) and are each separated by a city block; average bridge length is 70yds (64m). All the bridges are bascule types, hinged near a weighted end so they can be raised or lowered. "It's quite amazing how well-balanced these bridges are," Dear remarks.
The fixture Dear used for the project is the Martin Professional Exterior 600. "I think they have the best exterior fixture on the market," Dear says. He used a total of 144 of the full color-changing luminaires, plus 22 Martin ProScenium consoles and more than 35,000' (10.7km) of DMX cable. The project opened officially last July 31 (for the city's annual Venetian Night celebration) and is the final result of a massive collaboration between the LD and a plethora of city departments, including the Mayor's Office and the City Bureau of Electricity. "The Department of Bridges and Transportation was just wonderful," Dear says. "They gave me access to whatever I needed."
Dear used a standard plot for most of the bridges, since they are similar structurally (Lake Street, Michigan Avenue, and Lake Shore Drive had unique features that required individual plots). Franklin Street is an excellent example of the standard lighting plan.
"The nice thing about Franklin is that it's going to be redone this year," Dear comments. "It's also silver, and the rest of the bridges are done in burgundy, so the color on the silver really jumps out." For Franklin Street, as well as the other bridges covered under the standardized plot, Dear used a total of 12 Exterior 600s. Four instruments were positioned high on the bridge house structure, four were placed low on the sea wall, and four were placed in the nose of the bridge. All of the bridges are illuminated on both sides, so the instruments are spread out with six on either side of the structure.
A major challenge for Dear was the reverberation caused by traffic going over the bridges. "Bridge vibration is constant, and it was quite difficult to design a mounting bracket that would absorb this vibration so the whole thing wouldn't shake itself to bits," Dear says with a smile. "The unit would have vibrated off the bracket, and the bulb itself would never have lasted." Dear took the project to Collins Engineering of Chicago, which designed a suitable shock-mountable bracket for the units. "To be honest, we did go a bit overboard with the bracket in terms of load," Dear grins. "It can probably handle up to three tons, even though these fixtures only weigh about 100lb."
Once the bracket was engineered, Dear still had to deal with the placement of the units, which was different on each bridge, since they are all in different stages of repair. "We had to do a lot of custom design on the brackets in places," Dear explains. "We had to look at each bridge separately--we couldn't just generalize. The sea wall is in different stages of decay, so in certain places we had to use a shelf bracket, and in others we used a pedestal bracket." In areas where using the sea wall wasn't an option, Dear used a shelf placed on the bridge structure itself.
During Chicago's hearty winters, salt is applied liberally to the streets and the bridges. The salt collects in certain areas, which are where the bridges erode the quickest. "I tried to keep all fixtures away from them," Dear comments, since salt isn't the most fixture-friendly element.
The first specialized plot bridge, moving from west to east, is Lake Street, which is a bit separated from the other bridges, and is located where the Chicago River splits at Wolf Point. "Geographically, Lake Street is apart from the main branch; it's like the gateway to the south," he says. For the Lake Street bridge, which includes two bridge houses, Dear used 12 instruments: two on each bridge house, and eight on the underside of the bridge, with four on each side. Consequently, there are four fixtures mounted high and four mounted low to cover the span of the bridge.
Moving east, the next non-standardized bridge is Michigan Avenue, which has a span 80yds long and is near the ultra-luminescent Wrigley Building. This is a double-tiered bridge with two bridge houses, which Dear decided not to illuminate. "There really isn't a view of the guard houses from the street level."
For Michigan Avenue, he used 16 fixtures, 12 of which are mounted on the sea wall (focused on the bridge), with the remaining four on the structure of the bridge itself, lighting the sidewalk level. "The fixtures had to be located where they wouldn't blind the traffic or the boats," says Dear. "The Life Guard had to approve the location for the water traffic; in the end, we had to keep them close to the actual structure so bleed is reduced."
[An attempt to light the bridges was blindsided in the 1970s. "They mounted the fixtures a distance away, and when the boat operators approached the bridge, they'd be blinded all of a sudden," Dear remarks. "They shut the lights down in a week or so. Luckily, I was warned about these previous problems."]
The final non-standardized bridge is Lake Shore Drive, the bridge farthest east and the gateway to Lake Michigan. "It is a double-tiered bridge, and has bridge houses as well," Dear says. The bridge houses are four stories high, and are uplit on both sides. To illuminate the bridge, Dear used eight Exterior 600s on the sea wall, four on the sidewalk, and eight on the bridge houses, a total of 20 instruments. "Lake Shore Drive is the first bridge you can see from Lake Michigan. You can see it from a considerable distance in that direction, and in the opposite direction, you can see it as far off as Michigan Avenue, which is about half a mile away."
Lake Shore Drive also features a limestone surface, in contrast to the red oxide finish of the majority of the bridges. "It's a nice light surface to work with," Dear says. "On most of the other bridges, I was working off a burgundy finish. I was surprised at the level of saturation I was able to achieve with such a dark background--the colors still read really well."
For programming, "a ProScenium controller is located in each bridge house," Dear explains. The lighting program is synchronized with an atomic clock program called Socket Watch. "Each of the 11 bridges will be connected to each other--they'll be synchronized on either side of the river, and also along the river," he explains of his overall plan for the bridges, saying they will also be connected to Dear's computer, enabling him to update it from off-site. "Right now, we're working on making all the computers communicate with each other, then eventually they'll all be controlled by my laptop. It's like a grand version of PC Anywhere," he chuckles.
The final phase of the project includes video. Dear is getting several web cameras to observe the bridges. "When I dial in to the bridge houses to change a program, I can immediately make sure it's doing exactly what it's supposed to be doing. We'll have at least three cameras, but ideally I'd like one for each bridge." As the LD will be handling maintenance for the next five years, he'll have ample time to tend to the progress of his handiwork.
Sharon Stancavage is a Detroit-based concert and theatrical lighting technician.