East Lyme - The crews working on the Niantic River Bridge are digging a trench in the channel for cables and getting ready for a large barge carrying pieces of the lift span to arrive.

The projects in the channel have to progress steadily through the winter so the major underwater work will be finished by mid-April, when boat traffic picks up, Peter Finch, the project manager for Amtrak, said.

Amtrak is building a two-track, electrified, railroad bascule bridge across the Niantic River between East Lyme and Waterford, 58 feet south of its current location. Finch led a tour of the work site on Jan. 12 for U.S. Rep. Joe Courtney, D-2nd District, East Lyme officials, including First Selectman Paul Formica, and others interested in the project.

The $125 million bridge, funded with both federal stimulus money from the American Recovery and Reinvestment Act and Amtrak's capital budget, is expected to be complete in May 2013. The clearance under the bridge will increase from 11.5 feet to 16 feet, and the channel underneath will be widened to 100 feet from 45 feet.

It is the largest Recovery Act Amtrak project in the nation, Courtney said.

"Even Joe Biden didn't get one as big for Delaware," Courtney joked. The vice president is known for riding on Amtrak. A station in his home state received far less stimulus money.

Last weekend, the steel for the lift span, the structure that opens the bridge, left the fabricator in Alabama to begin the voyage by barge to Niantic. The trip is expected to take two to three weeks, depending on the weather. The pieces are so large that they have to be bolted together on another barge when they arrive at the site. The channel will be closed for several days when the lift span is installed.

Later this winter, the support beams for the east approach to the bridge will be loaded onto trucks in New Hampshire and brought to the state pier in New London.

It will require a special permit to get the beams through the state because they are huge and heavy, Finch said. They will be put on a barge in New London and travel to Niantic - the last major step in the process involving the channel this winter.

The structure for the approach on the west side and the operator's house are already in place, and the electrical control systems have been sent from Chicago.

The power cables are going into the trench in the water, rather than over the water, to ensure they will not be struck by boat masts. The contractor also will build new railroad tracks.

The old bridge will be demolished next winter.

The tour group walked on the new concrete boardwalk that was built along the beach as part of the project. The sand that will fill in the beach - about 76,000 cubic yards - is piled along the shore.

The town is responsible for upgrading roughly half of the boardwalk from wood to concrete. That end of the boardwalk was damaged during Tropical Storm Irene. The town is applying for federal funding.

Formica said the improvements to the boardwalk and beach will make East Lyme more of a destination. Courtney called the bridge replacement project "the poster child for the right kind of infrastructure investment," since it will improve both train service and the town.

J.MCDERMOTT@THEDAY.COM