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LEDs Bring Dazzle to Bridges

By Claire Swedberg | Sep 15, 2006
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Across the United States—Cities See Their Span in Lights

LIGHT EMITTING DIODE (LED) ILLUMINATION offers a host of advantages to port authorities, cities and counties with large bridges. LEDs use less power than traditional lamps, rarely need to be replaced, and provide unlimited options for color and color combinations. Whether using one color that becomes that bridge’s signature or by offering programmable light shows, more bridges are sporting decorative LED lighting.

Funding, however, can be a large obstacle. Because the lighting is strictly decorative, many communities have to finance the LEDs by raising money over many years. That has been the challenge for communities such as Lorain, Ohio. There, the Charles Berry Bascule Bridge needed something the community could be proud of, that would be entertaining, functional and unique to the area. Because it is a drawbridge, it has special requirements.

The four-lane bridge carries an average of 15,490 vehicles daily, and opens on demand for commercial water vessels while pleasure boats wait the hour or half-hour for the bridge to open.

The Ohio Department of Transportation offered up $150,000 and the county port authority, with some help from the city of Lorain and the county, came up with another $100,000. The city, together with Richland Engineering and MKC Associates Inc., prepared a Charles Berry Bridge Aesthetic Lighting Study to analyze the costs, types, effects and benefits of different lighting sources to illuminate the steel truss structure, as well as the pier and tower buildings. They agreed that LEDs were the most cost-effective, striking and colorful solution. They were unable to mount lighting fixtures directly to the bridge and wanted to avoid any light that would distract drivers’ ability to cross the Black River.

With plans in place, they hope to have the finished by the end of October, according to Karen Davis, special projects manager for Lorain County.

While the bridge already features traffic and gate lighting, the programmable, colored LEDs the county has in mind add another dimension.

Black River Landing, a park area just beyond the bridge, offers a scenic view. Color-changing LED floodlights will be used to illuminate the moving span and the steel structure when the bridge is in the open position and accent the pier and tower buildings with uplighting and low-mounted floodlights. Computer software will be used to control and program the lights, which can be specialized to an individual holiday or event.

In many larger waterways across the country, the lights have been on for months or years. Today, several large bridges lit with LEDs capture the attention of thousands on a daily basis. For many older infrastructures, LEDs provide the opportunity for an urban area or harbor to preserve the historic aspect of the structures, and make them dazzle as well.

From California

In Los Angeles County, the Vincent Thomas Bridge has been decorated with blue LEDs for more than a year. Pier Electric, a division of Rigging International, Carson, Calif., installed the lighting on the bridge, which extends across the Los Angeles harbor from San Pedro.

Project manager Mike Osborne said the company used nine electricians to install 160 LED lights. Workers ran a combined 20,000 feet of cable, with 5,000 on the upper level and 15,000 on the lower level.

Known as San Pedro’s Golden Gate Bridge, the 43-year-old structure is built on pilings, stretches 6,050 feet and extends 1,500 feet high and 500 feet across.

The Pier Electric crew spent five months preparing the bridge for the lighting ceremony that took place in February 2005. It took nearly five years for the bridge authority to agree on the color blue, which the U.S. Coast Guard approved, and at least that much time to raise the money.

There were two lighting manufacturers: FarLight, Wilmington, Calif., for the lower level; and Ledtronics, Torrance, Calif., for the upper level. A minority of Pier’s electricians were willing to climb hundreds of feet above traffic and waterways, and Osborne recalled handpicking people who were willing to make the climb. In addition, Rigging International provided ironworkers to spot them at the dizzying heights.

“We needed a special crew,” Osborne said, “We had a heck of a time getting guys to do that.” While the electricians may have been novices to on-bridge work, the Rigging International ironworkers were not. In fact, the company, had previously installed steel netting under the bridge to catch any bolts or other objects that might fall. Because they were accustomed to the rigorous work done on bridges, Rigging’s ironworkers developed a pulley system to get materials and cable where they were needed, did the actual movement of equipment, and accompanied electricians out onto the upper and lower levels of the bridge as they worked. Osborne called it a composite crew.

“The electricians did the electric work, but they didn’t want to go up there,” Osborne said. “So the electricians went up there under the safety direction of our iron workers.”

The bridge’s elevators brought men and equipment up the lower side and allowed electricians to run cabling and install lights from a traveling catwalk on the underside.

Gravity, weather and the bridge aside, a pair of falcons nesting under the bridge created Pier Electric’s foremost challenge, Osborne said.

“Certain times of the year, they were dormant, but other times they went into attack mode,” he said.

They waited to begin construction after the nesting phase, but he said the falcons remained aggressive even after that.

“They’d dive bomb our guys at 120 miles per hour,” he said. “They knocked a few hard hats off.”

There was no drilling or welding allowed, so all cables and fixtures were clamped onto the existing structure.

“We had to get approval before we put any kind of hole in,” Osborne said.

While installing the lights may have been strenuous, maintaining the LEDs is not, and they are designed to keep bridge crews from climbing the bridge any more than necessary. The life expectancy of an LED is 50,000 hours.

To the New York islands

After four years of illumination in upstate New York, the Mid-Hudson Bridge’s LED lighting system has needed minimal work.

JD Parrella Electric Inc. (JDPE), Newburgh, N.Y., installed the programmable LED lighting system on the Mid-Hudson Bridge. The two-mile span connects Poughkeepsie with Highland, N.Y., and was in need of a decorative solution to update the look and feel.

With funding in place, the New York State Bridge Authority had necklace lights installed in 2001. The lighting system, designed by Baker Engineering N.Y. Inc., Elmsford, N.Y., combines the technologies of Magni-Flood Inc., Amityville, N.Y., and Color Kinetics, Boston, to produce a strikingly colorful effect.

Baker’s design also includes two 3,000-foot-long messenger cables, more than 1,000 hangers supporting the communication and power cables, power conditioning and distribution as well as a lightning protection system. JDPE won the $300,855 contract after working on the Mid-Hudson Bridge in 1999. At that time, they were responsible for replacing all roadway lighting. With the LED project, JDPE sent an average of five electricians to the site for about six months. In addition to the LED lighting fixtures, JDPE was responsible for installing the PC-based control system that directs the lighting system.

Piasecki Steel Construction Corp., Castleton, N.Y., cut the holes JDPE needed to run lines through the bridge towers. The electricians did the rest, working at angles as steep as 30 degrees and at heights as high as 200 feet above the bridge itself, with another 200 feet to the water.

Like at Pier Electric, it was a challenge for JDPE to find electricians who could tolerate heights as well as the occasional gravity-defying angles working with a safety harness. “They were tied off, they couldn’t fall,” said Steve Parrella, president. “Still, just the matter of the height bothered some men. Before they were hired, they were made aware of the nature of the job.”

There was also the challenge of weather in an area where winds can gust at 50 mph at a regular basis. The crew held weekly safety meetings to review procedures and to address any concerns by the electricians. In addition, if it was too windy or rainy to safely work on the suspension cables, the crews focused on tasks such as running conduit through the bridge towers or prefabricating the cable supports that were used to hold the LED fixtures.

JDPE also devised a special pulley system consisting of bull wheels and rollers to pull wire to the highest points of the bridge. Special supports had to be used for mounting the pulley system because it had to be positioned directly onto the bridge’s suspension cable instead of on the road.

“When you bid a job, you usually don’t know how you will handle every detail,” Parrella said, referring to the need for pulley systems. “Using a little creativity is pretty common.” JDPE ran 142 LED lighting fixtures on the bridge, totaling more than 27,000 red, green and blue LEDs. The bridge system uses multicolored LEDs and a microprocessor to create more than 16.7 million colors and color-changing lighting effects. The job came with a one-year guarantee, Parrella said, and they didn’t need to make any changes during that year.

“There weren’t any problems that year,” he said. “The advantage is the bulbs just don’t burn out.”

Custom light shows are produced using Color Kinetics iPlayer 2 light show storage and playback device, which can store up to eight custom light shows that can be chosen at the push of a button. The iPlayer 2 playback device is located approximately one mile away from the bridge and data is sent to the lights through fiber optic cables.

The project, commissioned in August 2001 at a cost of $460,000, was completed on schedule and within the authority’s construction budget.

Parrella still takes pleasure in seeing the bridge lighted.

“This is the kind of thing, 30 years from now, the crew can still show their kids that’s what they did,” he said. “It’s really amazing.”    EC

SWEDBERG is a freelance writer based in western Washington. She can be reached at [email protected].

 

About The Author

SWEDBERG is a freelance writer based in western Washington. She can be reached at [email protected].

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