Construction

Award Winner: Lake Champlain Bridge
Team Members
Prime Construction: Flatiron Construction
Owner: New York State Department of Transportation
Project Engineer: HNTB
AGC NYS CORNERSTONE WINTER 2012
The new 2,200-foot-long Lake Champlain Bridge in northern New York State for owner New York State
Department of Transportation set a new industry standard for expedited construction. The two-lane steel arch
span structure across Lake Champlain, which replaces a structurally deficient two-lane bridge demolished
in December 2009, was constructed in less than 18 months. The bridge, which connects Essex County, N.Y. and
Addison County, Vt., was designed by HNTB and built by Flatiron under a bid-build contract.
The new bridge, with a signature network tied arch design, both preserves the historic integrity and aesthetic
quality of the original bridge, while incorporating features that will contribute to a 75- to 100-year design life. The
bridge’s main span is comprised of a basket handle modified network steel tied-arch 402-feet-long and 80-feet-tall
supported on delta fixed frames. The arch provides a 75-foot navigational clearance and 300-foot-wide channel
below. It has a basket handle arch with a network cable arrangement and internally redundant box tie girders
supporting a composite precast deck system. The new bridge has wider lanes to accommodate farm equipment, as
well as sidewalks for pedestrians and wide shoulders for cyclists. The project also included construction of 1,029-
foot approach on the New York side and a 769-foot approach on the Vermont side and demolition of temporary
causeways and ferry docks.
A main feature of the new bridge is the zinc metalized corrosion protection applied to the structural steel. It is one
of the largest bridges in North America to be completely zinc metalized. The pier footings are faced with granite
to protect the concrete substructures from ice damage. Additionally, the redundant design more easily allows for
maintenance and repairs.
The bridge’s entire main span structure was built on land at an off-site location. In an operation beginning before
dawn and lasting well into the night, Flatiron crews floated the Lake Champlain Bridge’s 900-ton central arch across
the lake and hoisted it nearly 80 vertical feet. The arch was joined to the approaches from the New York and
Vermont sides using strand jacks at each corner.
The bridge closure was a major hardship to the communities on both sides of Lake Champlain. For two years, the
nearly 3,400 daily travelers between Essex County, N.Y. and Addison County, Vt. relied either on a 100 mile detour
around the lake or a ferry system initiated after the old bridge structure was closed. Commutes that once took
40 minutes were increased to as much as two hours when the old bridge closed. The bridge provided a critical
connection between the two regions, which are economically linked and share services, including hospitals and first
responders.
Impact to the local community was the driving factor for the aggressive 18-month completion schedule. When the
original 1929 bridge was found to be in danger of imminent collapse and closed, initial estimates put completion
of a new bridge several years away. In addition, harsh New England weather challenged the accelerated schedule
further. In May 2011 crews watched helplessly as the water level at Lake Champlain rose to 103 feet-six inches
higher than the previous record, set a century ago. The storms flooded the assembly yard, where the arch was ready
to assemble, for three weeks.
Even with the weather setbacks, the team’s accelerated project delivery resulted in the bridge opening to traffic in just
18 months - a dramatically shorter time frame than anticipated. Motorists now enjoy delay-free crossings once again.
The new bridge serves not only as a replacement to the old bridge, but also represents a significant improvement
to the region’s infrastructure, assisting in re-building the region’s economy through a safe and innovative structure.
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