As dusk falls across the country, landmark buildings, monuments, bridges and public art structures that might be overlooked during the day come to life through dramatic baths of light set against the dark backdrop of night. The trend toward lighting landmarks and monuments has accelerated throughout the '90s and continues into this century. At the heart of the trend is a renewed sense of civic pride in our architectural heritage and a desire by many civic leaders to present their urban settings as active, thriving and safe destinations both day and night. For the Landscape Architect, landmark lighting presents a unique opportunity to create an image or identity for a structure. At night, landmarks can shine with less visual competition and higher contrast and drama than during the day.

"There is poetry and elegance in exterior lighting," said Randy Burkett, president of Randy Burkett Lighting Design Inc., a lighting design consulting firm in St. Louis, Missouri. "We start with a blank slate and create something that is almost completely aesthetic, not necessarily functional." Floodlighting can present a historic building or a new structure in a way it has never been seen or imagined before. Natural sunlight illuminates a building from above, or from the side as the sun rises and sets. Many of the details we view looking up at the building during the day are seen in shadow or against the contrast of a bright, sunny sky. At night, however, the real art of lighting design comes into play as selective highlighting from lower elevations or the pedestrian level creates an intense play of light and shadow against the structure's architectural details.

"Think back to your childhood when you played with flashlights under your chin," said Tom Kaczkowski, AIA, who heads the Lighting Group at HOK, a St. Louis-based international design firm. "On a larger scale, floodlighting carries this childhood wonder and curiosity." The details of how a structure is most effectively lit depends on the nature of the building, the surrounding vista, who will see the structure and the image to be projected. Some objects such as the national monuments in Washington, D.C., are lit for contemplative reflection while others like the historic brick water towers in St. Louis may be glimpsed for a just few seconds as motorists pass by at 60 miles per hour on the interstate. The Fog Walls, a public art project in Triangle Park, St. Louis, that combines colored light and fog, and sets the stage for visitors to a downtown sports arena, leaving them with a positive, lasting impression of the venue.

Monumental Lighting Techniques

One of the first issues a lighting designer faces is the nature of the building material and how light will behave on it. Surfaces such as limestone or brick absorb light well, while floodlighting bounces off shiny metal and through glass surfaces. The Fog Walls, for example, are made of perforated metal and use fog and steam to pull the light from inside the walls out into the surrounding space. "Exterior lighting is almost like theater," said Burkett. “You have to understand how to use light to enhance and highlight an object.” Another major decision lighting designers face is the color-rending characteristics of the light source as it falls on the object, according to HOK's Kaczkowski. In lighting a bronze statue atop Art Hill in St. Louis' Forest Park, Kaczkowski tested a mixture of yellow and white light. Yellow light alone made the statue look like a huge chunk of chocolate while white light gave it a greenish tint. When the two light sources were combined, the rendition of bronze looked just right.

The Fog Walls in St. Louis is a one-of-a-kind public art display and a unique construction challenge for McGrath & Associates, the construction manager on the project.

"Recent advances in light technology provide lighting designers with a much broader design palette and box of tools," according to Kaczkowski. The broad washes of light from short-lived incandescent light fixtures that were so common in the past are now complemented by long-lived, high intensity discharge light fixtures capable of delivering extremely precise beams or shafts of light. Angles can be tailored for the specific light source and the exact size of the object targeted. Lasers and light emitting diodes (LEDs) also have become more prevalent in lighting design over the past three years. The result? Less energy needed to deliver comparable light intensity and less stray light to pollute the night sky.

Colored light sources using glass filters, colored bulbs or gels also can celebrate a structure and the community. Different colors can be used to celebrate holiday seasons or a city's sports teams. New technologies also have impacted lighting control systems initially designed for Las Vegas applications are now available and affordable for a variety of outdoor environments, according to Burkett. Computerized controls play a critical role in special effects lighting, such as the chasing lights effect on the Fog Walls.

Landmark Lighting Challenges

All light sources have a finite life so designers must consider long-term replacement and maintenance issues, according to Kaczkowski. Safe and easy access for relamping is critical to the lifespan of a lighting system. So are simple light fixture construction details like properly designed gaskets and self-retaining screws. A screw dropped and lost during relamping can doom a light fixture to premature failure as water and bugs find their way into the fixture.

Damage through pedestrian traffic and vandalism also is a major issue. The subtle lighting against the black granite slabs of the Vietnam Veterans Memorial Wall in Washington, D.C. is installed in short, flat-topped pyramids that withstand the foot traffic from thousands of daily visitors. The white marble Washington Monument is bathed in floodlight from four large enclosures, four large ground-level grated boxes and four above-grade floodlights. All of the floodlights are protected from visitor damage even though the ground-level boxes are positioned close enough to the wall to encourage shadow play.

HOK installed the floodlights that illuminate statues and monuments in St. Louis' Forest Park in below grade light pits with covers resembling storm sewer grates. The grates are padlocked in place and the pits are concealed from view, set among plantings that surround the monument. When one statue was recently relocated, the five-year-old light pits, cover grates and internal floodlights all successfully made the trip to the new location.

Fog Walls - Lighting for Form and Function

Lighting often is a requirement of public space design, if nothing else but for public safety. Municipalities often establish foot-candle requirements for public areas to ensure adequate lighting. Unfortunately, the required illumination can generate too much light, according to lighting designers. "We try to illuminate large structures and objects for ambient light," said David Meyer of Peter Walker and Partners in Berkley, California. “The quality of ambient light that makes a space desirable can get washed down by safety lighting.”

The Fog Walls, a public art display in St. Louis, is an example of a dramatic lighting project that meets both aesthetic and public safety needs. Located directly in front of the Savvis Center, a major sports arena, and visible from I-64/US-40, this unique lighting display is an amazing piece of public art set in an open plaza. The project began, however, as a simple pocket park intended to move people safely between a MetroLink light rail station and the sporting arena.

The owner, Bi-State Development Agency which operates MetroLink, wanted to create a better connection between the station and the arena. A local private foundation recognized the opportunity to create a world-class public art display in this high-profile downtown location. The foundation offered to underwrite the cost difference between building the pocket park and creating a dramatic plaza with unique water and lighting elements.

"Everything about this project was a challenge because the components had never before been put together in quite this fashion," said Tom Rich, Vice President of McGrath & Associates, the construction manager for the project. McGrath became involved in the project a year and a half before actual construction began, helping the owner and the landscape architect refine the design, exploring constructability and developing scopes of work.

McGrath managed a number of subcontractors on the project including Murphy Company, mechanical contractors and engineers, and Guarantee Electric, both of St. Louis. "McGrath impacted every aspect of the project including materials specifications. For example, we recommended stainless steel over painted aluminum, which was originally specified for the project," said Rich. "We found that stainless steel was favorable both in price and durability." McGrath and Murphy Company encountered a number of unique challenges from the very beginning. A French drain system was needed to prevent flooding and the contractors had to install 6" pipe under existing brick sewer lines, taking care to keep the old lines from collapsing. When Pope John Paul II visited the arena while the project was underway, the site had to be cleaned up and made to look somewhat finished.

The design of the curved bank of walls was an evolutionary process, according to Meyer of Peter Walker and Partners. "The first concept was simply to bring a water element to the project. The concept for lighting the walls developed gradually through a progression of thought and design," Meyer said. "We envisioned a way of illuminating the water," said Meyer. "The walls were conceived as lanterns, something that would glow and bring light to the plaza."

HOK Lighting Group has completed work on many projects that exemplify the proper use of lighting, including the General Franz Siegel statue.

The Fog Walls were based on a much simpler wall designed by Peter Walker and Partners as a backdrop for performances on an outdoor stage in Des Moines, Iowa. On non-performance days during the summer months, that single panel wall produced fog as a water feature. The wall was mounted on a pedestal and lit by white uplights at the base. The Fog Walls, by contrast, is a bank of 10 walls, each 14' x 14' x 2' which function with lights and fog year-round. During the winter months, steam is created in a boiler which is heated by steam from the St. Louis city steam plant. In the summer, the fog is actually a cool mist, created with the same high-pressure atomized water technology used by orchards to prevent bud damage during a freeze, by restaurants in hot climates to cool their patio guests and by ski slopes to produce man-made snow. "The water used in both the steam and mist systems is highly purified to prevent mineral build-up. Only a few companies do vapor mist technology," said Rich. "That is an example of the challenges we faced. We constantly were asking who do you get to build it, how do you assemble it, how do you make it work as we were building the project."

Each of the Fog Walls has a series of five compact fluorescent fixtures mounted vertically at each end of each wall, for a total of 200 bulbs. The bulbs shoot light toward the center of the walls to create the lantern effect. Colored gels over the bulbs add color, red, green and yellow. The colored lights are computer controlled, offering a nearly endless array of lighting possibilities.

The Civil Courts Building

"The computer can turn each bank of bulbs on or off at .2 second intervals, which allows us to really animate the space," said Meyer. Each bulb is individually circuited so the computer can tell which bulbs to light, either as individual colors or as a combination of two or three colors. We can create a chaser effect so the light floats from one end to the other, we can change colors, pulse green to red to yellow or change colors sporadically.

The particles of fog mist and steam further enhance the lighting effect by carrying and expanding light and color into the space beyond the walls. "The Fog Walls help animate the plaza," said Meyer. "They frame the edges and actually capture the space, give it a sense of enclosure. The fog and lighting add to the quality of the space and move people along as intended."

Other St. Louis lighting projects funded by the same foundation include three historic brick water towers, all of which have been listed on the National Register of Historic Places since the early 1970s. The majestic Old Courthouse in downtown St. Louis, the site of the first two trials in the Dred Scott case in the mid-1880s, also has been majestically lit. Floodlighting of the Old Courthouse was designed for minimal impact on the building's historic fabric and for easy maintenance.

Lighting Bridges

The Old Courthouse

Bridge lighting is not new but has grown in popularity over the past few years. Since the late 1980s, many new Florida bridges including the dramatic Sunshine Skyway Bridge over Tampa Bay and the sleek modern Acosta Bridge in Jacksonville have incorporated decorative lighting into their design. Bridge lighting can be fairly inexpensive, costing less than .3% of total bridge costs for Florida's Roosevelt Bridge and Merrill Barber Bridge pier.

Bridges usually are lit by flood lights with specific beam patterns and shielding designed to focus the light away from vehicles. Fixtures typically are either high pressure sodium which offer a golden glow or more expensive metal halide type luminaries which glow white. Other colors can be achieved by adding lenses to the fixtures; timers and dimmers can also add variations during holidays or special events.

While dramatic lighting is not appropriate nor desirable for every landmark, building or bridge, it can offer a high-impact design element at relatively low cost. As we continue to borrow time-tested ideas and aesthetics from European cities such as Paris and combine them with the latest technologies in lighting sources and controls, our own cities will increasingly glow with nighttime beauty and civic pride. LASN

Mary Schanuel is the president of The Synergy Group, a marketing communications firm specializing in the construction industry with clients such as McGrath & Associates, The Lawrence Group, HDR, and Wiegmann & Associates.