Temporary bridge replacement in the US

A temporary bridge structure provided by Acrow Bridge is maintaining traffic flow for a key crossing in Vermont. The bascule bridge is allowing both vehicular and vessel traffic to pass during the reconstruction work to the North Hero-Grand Isle Drawbridge in Vermont. The US$60 million project involves replacing the historic twin leaf bascule bridge on Lake Champlain. This modular steel bascule bridge is allowing transport to continue to and from the Lake Champlain island towns of North Hero and Grand Isl
July 2, 2019 Read time: 3 mins
The temporary, modular steel structure from Acrow Bridge is helping ensure vehicle and vessel traffic can be maintained while a new crossing is built at Lake Champlain
A temporary bridge structure provided by Acrow Bridge is maintaining traffic flow for a key crossing in Vermont. The bascule bridge is allowing both vehicular and vessel traffic to pass during the reconstruction work to the North Hero-Grand Isle Drawbridge in Vermont. The US$60 million project involves replacing the historic twin leaf bascule bridge on Lake Champlain.


This modular steel bascule bridge is allowing transport to continue to and from the Lake Champlain island towns of North Hero and Grand Isle, Vermont. The bridge replacement work was needed due to an increasing number of costly emergency repairs over the last several decades. There had also been difficulty in sourcing parts for repairs.

Built in 1953, the bridge is located on US Route 2, the only connecting passage through the islands and a critical link south to the Vermont mainland. It carries 3,000 cars and trucks/day during the off-season and double that number during the summer and fall months. Without a span in place during construction, a detour of around 100km would result. In addition, the drawbridge allows for sailboats and large motor vessels to pass through the channel between Grand Isle and North Hero and is required by the 7007 US Coast Guard to be opened on a regular schedule and during emergencies between May 15th and October 15th each year. As each missed opening would incur large fines, the Vermont Agency of Transportation (VTrans) deemed a provisional lift bridge critical to the success of the multi-year project.  

Contractors broke ground on the project in July 2018 and continued their work on Acrow’s bascule bridge throughout the winter ensuring a fully functional structure for the first required opening of the season on May 15th, 2019. When the new structure opened, the old bridge was raised for the last time and will be dismantled in the open position so vessel traffic will not be impacted.

The Acrow bridge is 9m wide to accommodate two lanes of traffic. The movable bascule span is 18m long and the back span is 21m long for an overall length of 40m. The back span also includes a pedestrian walkway to allow access to the control cabin. Acrow’s structure is currently scheduled to be in service until May 2021, when traffic will begin to use the new drawbridge. The project completion date is estimated to be 2022.

The project owner is VTrans, with Cianbro Corporation acting as CMGC (construction manager-general contractor) partner. Acrow designed the bascule span, the back span and the mechanical systems of the rental structure, with temporary approach spans design and project engineering by Cianbro. HDR engineering was engaged as a consultant to VTrans.  

“After a number of years of preliminary planning by VTrans, the design process was addressed in a deliberate and collaborative manner so that the bridge opening deadline was successfully met in order to commence the new navigation season,” said Randy Needham, New England regional manager at Acrow. “It has been a pleasure to be a part of this important project, and know that our solution is believed to have cut down on the overall project timeline by a year.”

Road Structures

For more information on companies in this article

Related Content

  • Norway's bridge meets tough environmental targets
    May 2, 2012
    One of the world's longest bridges is being built in Norway – for traffic volumes of just 2,000 cars/day reports Adrian Greeman. The stunning landscape of the long sea fjords in Norway is one of its glories, attracting thousands of tourists every summer. But the high mountains and deep sea inlets are also one of the great obstacles to transport and development.
    Read More
  • Norway's bridge meets tough environmental targets
    February 27, 2012
    One of the world's longest bridges is being built in Norway – for traffic volumes of just 2,000 cars/day reports Adrian Greeman. The stunning landscape of the long sea fjords in Norway is one of its glories, attracting thousands of tourists every summer. But the high mountains and deep sea inlets are also one of the great obstacles to transport and development.
    Read More
  • Self-healing roads, slippery roads and slimmer roads
    November 24, 2017
    This month’s bitumen technology pages bring you self-healing roads, slippery roads and slimmer roads and explains why one UK contractor has started manufacturing its own polymer modified bitumen - Kristina Smith reports. Professor Erik Schlangen, who heads up experimental micromechanics at the Delft University of Technology is receiving calls from all round the world these days. And it is hardly surprising because he and his team have invented a great new technology: asphalt that heals itself.
    Read More
  • Rebuild project for historic Pennsylvania bridge
    September 10, 2015
    Rebuilding work is planned for a historic bridge in the US state of Pennsylvania to ensure it remains able to carry current traffic volumes. The work is being managed by consulting engineer Michael Baker International. Pennsylvania Department of Transportation (PennDOT) selected Michael Baker International for the US$5 million engineering and design project that will focus on the western spans of the Market Street Bridge in Harrisburg. Rehabilitating this critical traffic artery in Pennsylvania's capital re
    Read More

Highlighted Content