With snow falling, the Lake Champlain Bridge connecting Addison, Vermont, with Crown Point, New York, was demolished in the blink of an eye at 10:02 this morning. The sequence of charges appeared to go off as planned and the superstructure of the bridge debris fell straight down into lake. Reporters at the scene were caught off guard as a one-minute warning alarm went off just a handful of second before the bridge was detonated. Smoke and snow obscured what was left of the bridge for several minutes. Replays of the demolition can be found at the local network affiliates and at NYSDOT (CLICK HERE FOR VIDEO). Construction (PICTURES) of the new bridge is expected to start this spring. A temporary ferry is expected to start running soon very near the site of the now former Champlain Bridge.
The New York State Department of Transportation (NYSDOT) and the Vermont Agency of Transportation (VTrans) released a joint statement shortly after the demolition saying a critical task in the process reestablishing a transportation link between their states, by demolishing the 80-year-old bridge, thus paving the way for a new bridge that will sit in the footprint of the former one.
As thousands watched in person, via the Internet and on television, New York’s blasting subcontractor, Advanced Explosives Demolition (AED), used some 500 pre-set high-tech linear-shaped explosive charges to cut through the steel at 17,000 feet per second, bringing down the 80-year-old span in less than ten seconds.
Following a burst of bright light and a nearly simultaneous boom of greater than 130 decibels, spans 4 through 9 - or more than 80 percent% of the bridge - dropped into Lake Champlain. The fallen portions and the concrete piers that supported them will be removed before next spring along with the remainder of the bridge. The lake in that vicinity is to be open to navigational traffic in April.
"It was an honor to be a part of the effort today to bring down the old Lake Champlain Bridge. This is an important step in the processes of reestablishing this critical transportation link," said Vermont Governor Jim Douglas. "We want the new bridge in place as soon as possible, and today’s effort will ensure that we are ready to begin building a replacement bridge in the spring, when the weather permits. This collaborative project with our partners in New York will protect our treasured connection between Crown Point, New York, and Chimney Point, Vermont that has existed for centuries."
“We continue to move as quickly as possible to restore the vital connection between our states, and resume normal transportation across Lake Champlain on behalf of those who live near and depend on it in their daily lives,” said New York Governor David A. Paterson. “The bridge coming down weighs heavy on our hearts, but it is a critical task that is now completed. The former Lake Champlain Bridge, which served our states well since it opened in1929, had outlived its lifespan. Once the new bridge is built, we will have an even more majestic connection between our states, and the communities in the surrounding areas will benefit from a span that will be more modern, but will preserve the environmental and historical integrity of the area.”
The former Lake Champlain Bridge had been ordered closed on October 16, 2009 when engineers who were in the process of repairing the upper portion of the span detected an exposed crack in one of the piers that had previously been submerged. Despite NYSDOT’s rigorous inspection schedule which had shown underwater deterioration at the rate of about an inch every five years for some twenty years since New York and Vermont gained control of the bridge, from 2005 to 2008 an inexplicable 14 inches of additional deterioration had occurred, making the bridge unsafe and unstable.
The 2,184-foot-long bridge, also known as the Crown Point Bridge, was opened to traffic on Aug. 26, 1929 with a ribbon cutting ceremony conducted by New York Governor Franklin D. Roosevelt and Vermont Governor John E. Weeks. It was a toll bridge until 1987 when the Lake Champlain Bridge Commission that operated it was abolished and ownership was transferred to New York and Vermont. On November 9, after the closure of the bridge and the conclusion of intensive testing, the two states announced that the investigation determined that it was not feasible to repair, and set the course for it demolition and construction of a new bridge in its place.
John Grady, the head engineer for District One and the demolition project supervisor, and NYS-DOT communications director Deborah Sturm Rausch, described what the Idaho company Advanced Explosives Demolition had been doing for the past week, why there had been a postponement, what arrangements had been made for public viewing on Dec. 28, and how all this had been affected by the overriding goal of maintaining safety.
Over and over, Rausch repeated that safety was the agency’s number one concern. That was why only carefully credentialed members of the press will be allowed at the Crown Point historic site viewing area a little more than 1,000 feet from the bridge, she and Grady explained.
Press corps members were advised to bring earplugs at least, because even at 1,000 feet the anticipated acoustical shock wave from the simultaneous detonation of more than 500 charges will reach 130 decibels. According to Dangerous Decibels.org, a nearby clap of thunder, at 120 decibels, can cause immediate hearing damage. Since the decibel scale of air pressure is logarithmic rather than arithmetic, a 130 decibel sound is close to 10 times as loud as 120 decibels.
Asked how far along Lake Champlain this sound might be heard, Grady said no one knows. But sound travels extremely well along the flat lake, he said.
The experts have advised there is likely to be shrapnel, possibly to as far as 800 feet from the blast site, Grady said. At Crown Point, some windows have been boarded over, and a blasting curtain protects one vulnerable point.
The Federal Aviation Administration (FAA) has established a 2,000 foot no-fly zone. Access to certain roads and buildings also will be restricted to ensure public safety. For their protection, the public is required to abide by the safety zones.
The Coast Guard has ordered a water safety zone to extend 1,000 feet in each direction from the bridge from Dec. 20 through April 15, 2010 according to a NYS-DOT release. That is the date by which the international waterway must be cleared for passage. Questions about those requirements can be directed to the Coast Guard Sector Northern New England Command Center at 207-767-0302.
In order to protect the public during the Lake Champlain Bridge demolition and subsequent debris removal, the United States Coast Guard (USGS) has established a water safety zone of 1,000 feet on either side of the bridge. No vessels, vehicles or persons are permitted within this area without approval from the Captain of the Port, Coast Guard Sector Northern New England. This safety zone is in effect from 8:00 a.m. on Sunday, December 20, 2009 until Thursday, April 15, 2010, to allow the channel to be cleared of debris. Any questions regarding the safety zone should be directed to the Coast Guard Sector Northern New England Command Center at 207-767-0302.
The Federal Aviation Administration has established a 2,000 foot no-fly zone. Spectators have been told not to congregate on the NY railroad tracks, which parallel a road there, because high-speed trains frequently use them.
As for going onto the ice, NYS-DOT pointed out that the blast will send a shock wave through the ice (though not much land-based vibration) that will greatly weaken it. “The public should under no circumstances attempt to view demolition from the ice, or venture onto the weakened ice following demolition,” a Dec. 23 press release said. Ice that in other years was stable will not be so for some time, they said, because the demolition crews will use ice-breaking to maintain access, then the ferry that is being created not far from the bridge will have to break ice by constantly running.
The contractor has said this job is “one of the largest” they have done, Grady said. More typically they use 100 to 200 pounds of explosive, he said.
In New York, the public is being directed to Port Henry, where police will direct people to parking and viewing areas. In Vermont, Route 125 will be made one-way going toward Chimney Point and Route 17 will be one-way going away, and no parking will be allowed near the bridge. As of Dec. 23, no good viewing or parking areas had been identified along Route 125, no bus shuttle had been scheduled, and the Vermont Agency of Transportation had said that Route 125 would be closed if it became unworkably clogged.
On Dec. 22, however, Rausch said the best place to see it happen may be in the warmth and safety of one’s own home. A live Internet broadcast will be available at www.nysdot.gov/lakechamplainbridge, she said. For later, there will be so many TV satellite link trucks on hand that NYS-DOT has designated a special area for them, and has suggested that press representatives arrive two hours early to maximize their chances of wedging in. Then, she observed, there is always YouTube, where the bridge is likely to live forever.
Those who have visualized the bridge being blown to bits may be disappointed to learn that the goal is to have the middle five sections of the structure drop into the lake by their own weight. Most of the advance work has involved making cuts to weaken or remove girders (and save the commemorative plaques and lighting poles), Grady said.
Due to cold and windy conditions, which have affected safety, it has not been possible for Advanced Explosives to cut any many girders as they normally would on such a job, Grady said. Also, he said, the ice forming on the lake has impeded the barges and lifts that are being used to raise workers, he said.
So instead, more than 800 pounds of RDX explosive will be used to cut much of the iron, he said. A Brittanica online article states that cyclotrimethylenetrinitramine, also known at one point in Britain as Research Department Explosive (RDX) and in this country sometimes called cyclonite, was first used widely in World War II. A Florida State University history of explosives says that it is “a white crystalline solid usually used in mixtures with other explosives, oils, or waxes. RDX has a high degree of stability in storage and is considered the most powerful high explosive.”
But this power will not produce a blast in all directions, Grady said. Rather, Advanced Explosives will use “shaped charges,” which will send the force of each explosion in one direction, to a small area. That force will travel at 17,000 feet per second (sound travels at 1,125 feet fps, the equivalent of 768 miles per hour) and strike with an impact of about 2 million pounds per square inch--which will cut through the steel girders “like a knife cuts through butter,” he said. Those familiar with the history of World War II may recall that a handheld bazooka could destroy a tank because it fired a shaped charge capable of similarly penetrating thick armor.
“We’re simply cutting it and it will fall straight down,” Grady said. Parts on land in Vermont or New York will be dismantled by conventional means. In between, girders are likely to protrude from the surface nearer the shores, he said, but in the middle, where the lake is 45 feet deep, they may not be visible.
Whether above or below the surface, the historic scrap iron will become the responsibility of another subcontractor, Sessler Wrecking of Waterloo, New York. Cranes on barges will left the remains, with the help of divers if necessary, then these will be cut into pieces small enough to be trucked away.
Some of the material may be saved to create a memorial, something Rausch said has been mentioned by an advisory group and by attendees at public meetings. Asked by one member of the press how many tons of scrap the bridge will produce, Grady could only say, “It’s a whole lot.”
As the lowest of seven bidders, Advanced Explosives estimated their part of the job will cost $188,000, Grady said. The project as a whole will cost about $4 million.
Grady dismissed one questioner’s suggestion that the delay might cause people to lose faith in the effort being made to address a serious transportation need. Work had been continuous--"You can see the welding torches going well into the night," he said. Rausch backed him up: “The process never stopped.”
Likewise, they rejected the “red tape” theory of how long this was taking. Beyond obtaining necessary approvals, the contractor had an immense amount of planning to do, which could not begin until their bid was selected and they came to the site, Grady said. Asked about the idea that lead paint would flake off during the blast, he said Advanced Explosives removed any paint near the places where they used cutting torches, and the rest wouldn’t be a problem because lead is not soluble in water.
Rausch summed up the ongoing effort by saying, “This project has been fast-tracked since the beginning.”
The demolition also was streamed live on the New York State Department of Transportation Web site, as well as the Web sites of several media outlets in New York and Vermont. A video of the demolition is available on the NYSDOT Web site at https://www.nysdot.gov/lakechamplainbridge.
NYSDOT engineers have been working with HNTB, an award-winning design consultant, to develop designs for the replacement bridge. HNTB, which has consistently ranked among Engineering News-Record’s top design firms, fast-tracked the design phase of the new bridge, and presented its recommendations to the bridge Public Advisory Committee (PAC) as well as the general public earlier this month. New York and Vermont created the PAC in October 2009 to represent the public views regarding the old Lake Champlain Bridge and its replacement.
Both the PAC and the general public, through an in-person and an on-line survey made available by NYSDOT, viewed six renditions for a replacement bridge, and recommended a Modified Network, Tied Arch Bridge concept. The Modified Network, Tied Arch Bridge is a steel structure with a handle-like arch along the main span. Multiple redundancies in the design make this bridge significantly safer than the existing structure and ensure at least a 75-year service life. The design also is visually pleasing, complementing the mountainous back drop. A rendering of and more details about the Modified Network, Tied Arch Bridge can be found at www.nysdot.gov/lakechamplainbridge/alternatives.
Public preference will be one of many factors considered by NYSDOT and VTrans in the final determination of the design of the replacement bridge which is expected in January after further consultation with project stakeholders. Preliminary construction work for the new bridge is expected to begin in the spring 2010, and the new bridge is expected to be completed by late summer 2011.
New York and Vermont officials continue to work to establish a new ferry service in the vicinity of the bridge by the end of January.
Source: Ed Barna, Vermont Business Magazine. Governor Douglas' office. 12.28.2009.
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