BATH – The state has completed a $12.5 million renovation of the old Carlton Bridge, a 74-year-old landmark that crosses the Kennebec River between Bath and Woolwich.

The span, familiar to millions of commuters and tourists who travel on U.S. Route 1 in Maine’s midcoast region, was replaced by the Sagadahoc Bridge, which carries cars and trucks over the river. Only trains will use the Carlton Bridge now.

The renovation began in August 2000 and was completed, with little notice, in November of this year.

Part of the renovation includes replacement of the tender’s house. As part of the improvements, the tender can raise the railroad deck with a push of a button whenever ships have to pass through.

The tender also can control the speed of the span as it is being raised or lowered. An air horn audible to rail and boat operators sounds when the deck is being raised.

Video cameras have been installed at different locations on the bridge so tenders can see boat and train traffic on a television screen. The new tender’s house is below the bridge deck, not above it, as the old one was.

“The old place was pretty shaky. It used to rattle when trucks drove across the bridge,” said tender Christopher Pester. “I like this place much better.”

Windows in the new tender’s house provide views of Bath Iron Works and the city of Bath’s waterfront.

Other improvements include new rivets and lacing bars, replacement of the bridge’s original electrical components, reinforcement of towers and installation of span locks that keep the rail deck locked indefinitely in an up position.

Next year, the state will spend an estimated $20 million to repaint the bridge.