Controlled Demolition Safest, Most Effective, Fastest Way to Demolish Old Kosciuszko Bridge
First Ever Implosion of Major Bridge Using Explosives in New York City
944 Linear Shaped Charges Strategically Placed on Bridge; Over 1,600 Cuts in Steel Members to Weaken the Steel for Controlled Amount of Charges to Sever the Steel
20 Steel Truss Spans Dropped - Total Length of 3,100 Feet or Nearly Two-Thirds Mile - Fall Intact for Minimal Dust and No Flying Debris
Governor Andrew M. Cuomo today announced the energetic felling of the old Kosciuszko Bridge in both Brooklyn and Queens. Energetic felling is the chosen process because it is the safest, quickest, most effective way to demolish the old bridge that is the least intrusive to the surrounding community. The felling is part of the $873 million Kosciuszko Bridge project, which is replacing the former 78-year-old bridge with two new state-of-the-art, cable-stayed bridges. The felling was the first ever implosion of a major bridge infrastructure using explosives in New York City. The state-of-the-art new twin span Kosciuszko Bridge has been expedited and is scheduled to be completed in 2019, a full four years ahead of the original project schedule.
"After years of stagnation and stunted ambition, we are building across the state bigger and better than before, and the energetic felling of the old bridge to make way for the new, on budget and ahead of schedule bridge, showcases our renewed commitment to building new, inspiring infrastructure for the future," Governor Cuomo said. "The new cable-stayed bridge is a monument that brings people together, straddling two boroughs that have welcomed generations of immigrants from all over the globe."
Governor Cuomo opened the first span of the new Kosciuszko Bridge in April, celebrating completion of the $555 million first phase of the project, the largest single contract the New York State Department of Transportation has ever undertaken. The Queens-bound bridge is carrying three travel lanes in each direction of the Brooklyn-Queens Expressway until the second, Brooklyn-bound bridge, is completed under a separate Phase II contract, valued at $318 million. When the new bridge is complete, there will be five Queens-bound travel lanes of the BQE and four Brooklyn-bound travel lanes, for a total of nine lanes. In addition, there will be a 20-feet-wide multi-use trail with spectacular views of Manhattan. The bridge carries approximately 200,000 commuters daily.
The process of energetic felling isolates key structural supporting members of the bridge and cuts them with linear shaped charges to safety drop the steel trusses to a prepared landing area below. The lowering occurs in seconds, minimizing any long term potential impact to adjacent properties and vehicles traveling on the new bridge. A total of 20 steel truss spans were dropped - 10 spans on the Brooklyn Approach and 10 spans on the Queens Approach - with a total length of 3,100 feet, nearly two-thirds of a mile. A total of 22 million pounds of steel from the old Brooklyn and Queens approaches will be recycled as scrap metal.
The steel trusses dropped straight down, with the highest drop over 30 feet near the Main Span towers. In addition to the removal of the concrete median barrier and asphalt overlay on the bridge deck, the Contractor also hammered sections of concrete from the steel grid deck on several spans in order to reduce the weight of those spans and for reducing vibrations generated from the impact of the steel trusses onto cushioning berms. Vibration analysis considers adjacent properties and the adjacent new bridge to ensure cushioning berms, as required, absorb the bridge as it drops to ensure vibration effects is negligible. The cushioning berms range from 15 to 25 feet in height and consist of either recycled concrete or soil. The berms themselves are designed to capture the bottom chord of the trusses being felled so the truss cannot move sideways in the wrong direction following impact.
Linear shaped charges were used by Controlled Demolition, Inc. as the primary steel cutting charge. A very small quantity of strategically placed shaped explosive charges will be used to sever each span. It's estimated only 12 pounds of charges per span will be used. A total of 944 charges have been placed on the old bridge. The explosives manufacturer has confirmed that there are no hazardous chemical byproducts resulting from the use of the explosives proposed.
Use of explosives is minimized. The use of explosives does not blow up the bridge. Rather, the explosives are strategically placed like surgical instruments that cut key steel connections allowing gravity to do the work.
Over 1,600 cuts were made in the steel members, including truss chords, stringers, and wind bracing, to weaken the steel and allow a minimal amount of charges to be used to sever the steel and drop the truss spans.
The process meets all New York Codes including New York City Fire Department (FDNY) Codes and MTA Codes. There is minimal dust and no flying debris from this controlled demolition. Building implosions as seen on TV create dust as the building collapses in mid air and the building components crumble as they fall to the ground. The Kosciuszko Bridge existing approach spans will not break apart, they will fall intact. As a result there are no air quality concerns.
The former bridge's main span over Newton Creek was lowered onto a barge and removed on July 25.
The new cable-stayed bridge is a monument that brings people together, straddling two boroughs that have welcomed generations of immigrants from all over the globe.
New York State Department of Transportation Acting Commissioner Cathy Calhoun said, "Because of Governor Cuomo's vision, we have a new Kosciuszko Bridge, the first new bridge built in New York City since the Verrazano Bridge in 1964. Removing the old bridge approaches is a significant step forward on the second bridge, which is going to reduce traffic congestion and improve the quality of life here for generations to come."
Congresswoman Carolyn B. Maloney said, "I am delighted to join Governor Cuomo as we say good-bye to the last remnants of the old Kosciuszko Bridge, a span that had outlasted its time. I am pleased to have provided $670 million in federal funds to replace the old bridge and thrilled that the state has moved quickly under Governor Cuomo's leadership to build a new state of the art bridge that will soon be joined by a second bridge that will give New Yorkers 9 lanes of traffic, a new pedestrian/bikeway and new parks. We do not lament the passing of the old bridge."
Senator Martin Malave Dilan said, "With today's energetic felling, we are one step closer to a fully operational, modern structure that will advance commerce and enhance the City's transportation structure. I'd like to thank Governor Cuomo for his unwavering support for this and projects across New York."
Assemblyman Joseph R. Lentol said, "By building this beautiful new bridge, we are once again honoring Major General Kosciuszko and the Polish community for the next generation. The first span already serves as a beautiful addition to our skyline, and we are thrilled to be taking another step forward today toward completing the second span. We would not be here today if it were not for the leadership of Governor Cuomo, and on behalf of the entire community I thank him for his leadership."
Assemblywoman Maritza Davila said, "The new Kosciuszko Bridge is an inspiring symbol of what makes New York great. Today's energetic felling is another step toward building today for a better tomorrow. Thank you, Governor Cuomo, for your unyielding leadership on this bridge and for all of your historic infrastructure investments."
Queens Borough President Melinda Katz said, "Today's energetic felling will pave the way for the second span of the new Kosciuszko Bridge to be built where the old bridge once stood. It is a major step toward a fully complete Kosciuszko Bridge that not only connects two boroughs of the greatest city in the world, but also symbolizes a tangible reminder of New York as a nationwide leader in innovation."
New York City Council Majority Leader Jimmy Van Bramer said, "The Kosciuzko Bridge replacement has been an example for modern, public construction projects, not just in New York, but throughout the nation. Congratulations to Governor Cuomo on the demolition of the old Kosciuszko which is a major step for this project that will help all who travel on the BQE."
New York City Council Member Elizabeth Crowley said, "This energetic felling is a major step in revitalizing a structure that was well past its prime. With a new Kosciuszko Bridge, we are bringing the Empire State full speed ahead into the future. I look forward to working with Governor Cuomo as we continue to take New York's infrastructure into the 21st century."