The Gold Star Memorial Bridge, which carries tens of thousands of cars each day over the Thames River between New London and Groton, is in line for major repairs that will begin this month and continue for the next five years.

The state Department of Transportation is starting this spring a two-year project to improve the southbound structure and is planning for a later overhaul of the northbound span that calls for replacing the entire deck.

The southbound project is slated to begin April 17, weather permitting. Construction work mostly will take place during the day and will entail lane closures and the installation of Jersey barriers along the length of the bridge.

Southbound

Components of the bridge's southbound span, built in 1973 with a rehabilitation project done in the 1990s, need repairs after being exposed to salt, debris and traffic over the past quarter century, according to DOT engineers. The work is expected to preserve the bridge for the next 25 years.

Keith Schoppe, the project engineer for DOT, described the $30 million construction work as a "classic rehabilitation project on a large scale," as the Gold Star Bridge, spanning a mile, is the longest bridge in the state.

The project will entail stripping off the deck's asphalt and waterproofing membrane to get down to the concrete, which will be inspected using a "hands-on" approach to detect any deteriorating areas, engineers said. Deteriorating areas then will be patched up.

The project further calls for replacing the bridge's modular deck joints, which allow the bridge to expand and contract as needed. A new higher-tech waterproofing system will be applied and the deck will be repaved, engineers said. Steel will be repaired and replaced as needed, and the bridge's substructure also will be patched up, they said. The replacement of signs, navigation lights and the Route 32 northbound connector ramp are among other components of the project.

The contract was awarded to Mohawk Northeast Inc., according to Schoppe. DOT anticipates the southbound work will be finished by fall 2018.

Construction will take place in multiple stages, with Jersey barriers sealing off work zones on the bridge. DOT plans to work on the left side of the southbound bridge for the first half of the project, and then work on the right side of the southbound bridge.

The DOT plans to keep four of the five southbound lanes open during the start of the project and over the busy summer months from Memorial Day to Labor Day, according to Robert E. Obey, district engineer for DOT's District 2 Construction. Three lanes will be open at all other times.

For the first phase of construction, the bridge will be reduced from five 12-foot lanes and wider shoulders down to four 11-foot lanes with narrower shoulders, Obey said. A Jersey barrier will be installed on the left side along the entire length of the bridge. After Labor Day, the barrier will be shifted over, and the bridge will be reduced to three lanes.

Schoppe said most of the construction work will take place during the day.

Obey said DOT typically aims to conduct most of its highway repairs at night, but it would have been challenging to do the project with temporary nighttime lane closures, given the extent of the work needed. The barriers will allow DOT to extend work hours, work in multiple locations on the bridge at the same time, and make it safer for workers and drivers, he said.

DOT also temporarily may close some lanes at night as needed during parts of the project, Obey said. DOT said it will announce lane closures to the public in advance. Warning signs will alert drivers to lane shifts.

The sidewalk across the deck will be maintained and remain open for most of the project, though periodic closures will be required, engineers said.

Northbound

The northbound span, built in the 1940s, about 30 years earlier than the southbound span, needs more extensive work, according to DOT engineers. Work, estimated to cost more than $200 million and with a tentative start date of spring 2018, will include the replacement of the entire bridge deck and strengthening and upgrading steel.

The northbound span is built of structural steel that is outdated compared to today's standards, Obey said. The bridge will be upgraded to accommodate today's vehicles and loads, he said; the old steel will be sandwiched between plates of stronger steel, and steel that has been water damaged will be repaired.

Spot painting, concrete patching of the bridge's piers and replacement of bearings are among other repairs called for in the project.

"Southbound, we're preserving an iconic structure," Schoppe said. "Northbound, we're upgrading an iconic structure."

Obey said DOT is looking to take advantage of accelerated bridge construction techniques, in which panels for the bridge deck would be built off site and then brought to the bridge.

Obey said the northbound project, anticipated to take about four years, still is in the design phase. 

The strengthening and reinforcement of the steel on the bridge, estimated to take about two years, is expected to have minimal traffic impacts and some nighttime lane closures at times, but the deck work, about a two-year project, would require lane closures with barriers, he said.

Obey said DOT is studying sequencing and staging for the project, with the goal of avoiding impacts to traffic on both the northbound and southbound spans at the same time.

The replacement of the bridge deck will be done with the goal of keeping three lanes open at all times, Obey said. DOT also is committed to looking at having four lanes open when possible.

Construction impacts 

As workers repair the southbound span of the bridge, tow truck service will be stationed near the bridge, according to DOT.

"We would encourage everyone to travel at a safe, reasonable speed through any work zone," Obey added.

With southbound work slated to begin this month, local officials stressed the importance of notifying residents, major employers and emergency management personnel of traffic details.

Groton Town Manager Mark Oefinger said repairs to the bridge are necessary, and he has confidence DOT has worked out the plan.

"This work needs to be done," he said. "It's a big, wide bridge. Even if you lose a lane or two at a time, as long as you give people enough notice, it generally works out."

The changes may take some getting used to, particularly in the beginning, so signage, especially of exit and entrance ramps, will be critical, he said.

Once he receives details on traffic management, he said he will sit down with police, ambulance services and firefighters to go over the details.

New London Mayor Michael Passero said that from what he has learned so far, the project would not have much of an impact on local roads.  

Groton City Mayor Marian Galbraith said she has learned DOT is trying to minimize any traffic disruptions and keep the bridge open to four lanes during the summer, which is very important during the busy season.

"Our plan is just to keep notifying our residents and our employers of what is happening," she said.

k.drelich@theday.com