Bridge Preservation LLC photo. Surface preparation was performed using scarifying and shot blasting.
Anyone who has traveled New York State’s Northway (Interstate 87) over the Mohawk River knows it is Thaddeus Kosciusko (as in the Thaddeus Kosciusko Bridge) — better known as the Twin Bridges.
Constructed in 1959, the structure is a pair of identical through arch bridges, made of steel, that span the river between the towns of Colonie in Albany County and Halfmoon in Saratoga County in New York’s Capital District. Each span carries three northbound and southbound lanes of Interstate 87 between exits 7 and 8. The Interstate 87 is a key connecting route for commercial truck traffic, commuters and long distance travelers, and receives more than 100,000 vehicles per day.
Like most bridges of that vintage, the spans require increased maintenance to function as designed. Replacing the decks was a key element of their rehabilitation. The two-phase, $29 million project, funded by New York Gov. Andrew Cuomo’s NY Works program, began in the summer of 2012. The northbound bridge deck was replaced in September and October of that year. The southbound bridge deck was replaced in April and May of 2013.
The project was designed to meet the goals of Gov. Cuomo’s Driver’s First initiative to minimize disruptions to motorists. To that end, northbound traffic was reduced to a single lane and two southbound lanes were shifted onto the northbound span. The southbound bridge was closed at 10 p.m. on Fridays and reopened before the Monday morning rush hour.
According to New York State Department of Transportation Commissioner Joan McDonald, “New York’s reinvestment in these bridges will increase their lifespan, save taxpayer money by avoiding more costly repairs in the future and will greatly improve safety for all those who travel over them every day.”
The bridges’ suspension cables were replaced in 2010. The method used for that work was designed to take place during the week with no lane closures. Additionally, the cables were required to be under normal weight-bearing loads (including live traffic) in order to be properly positioned and tensioned.
There were three issues that prevented replacing the bridges lane-by lane:
• The design of the existing bridge decks was not of a “modular” structure that would enable workers to remove the equivalent of a lane at a time. Instead, the decks had to be taken up largely across the entire width (all three lanes) of each bridge. The deck was replaced using precast panels that allowed the new deck to be put down more rapidly, without the curing time necessary when concrete decks are poured on site.
• Even if one deck was replaced at a time, shoulder space was required to provide an area for disabled vehicles, traffic enforcement and other emergency operations. That, combined with the need to set a barrier protecting the work area from traffic, meant that with a three-lane bridge only one travel lane would be able to be provided.
• If only one travel lane is open on a bridge, the decks could be replaced faster and minimize traffic disruption than if the entire bridge had to be closed for a weekend at a time.
In addition to the bridge deck replacement, the project included drainage installation, excavation, grading and paving the crossovers. The northbound deck work included maintaining traffic, bridge closures, demolition, pre-cast panel setting, installing shear stud, rebar and dowels, formwork, placing concrete and installing road plate.
Upon completion of the northbound deck, more than 100 precast bridge panels were installed, 9,776 holes on the structural steel connection were field drilled and 3,100 tons of existing bridge were removed.
The project’s general contractor was The Lane Construction Corporation of Chesire, Conn. Founded by railroad engineer John S. Lane in 1890, Lane constructs bridges, highways, locks and dams and mass transit and airport systems in more than 20 states.
A Little History
The Thaddeus Kosciusko Bridge is named in honor of Tadeusz Kosciuszko (1746-1817), the preeminent national figure in Poland’s fight for independence. Kosciuszko arrived in Colonial America a month after the July 4, 1776, Declaration of Independence and remained a notable military leader throughout the Revolutionary War. He attained the rank of general as well as honorary American citizenship before returning to Poland in July 1784,
The bridge opened as part of the Adirondack Northway, a 176-mi. highway linking Albany and the Canada-United States border at Champlain. The Interstate 87 section was formally inaugurated by Gov. Nelson Rockefeller on May 26, 1961.