A new 147-foot rolling bascule span was floated into place Tuesday afternoon as part of a $16 million project to replace Canadian Pacific Railway's century-old swing bridge over the Black River in La Crosse, Wisconsin.

It was a thrill for those watching from a public viewing area set aside at the F.J. Robers Co. terminal at 816 S. Bainbridge St. on French Island. The viewing area opened Monday morning.

"This is history," Bob Melsheimer of La Crosse said late Tuesday afternoon, as crews continued working on the railroad bridge. He had been watching and photographing the work since mid-afternoon and also had been snapping pictures there Monday.

"I'm a rail fan," Melsheimer said. "I've lived here all my life."

"This is a momentous occasion," said Keith Swanson of French Island, who went to the public viewing area late Tuesday afternoon after making three trips there Monday.

"It's marvelous that man can do this, and that the (old) bridge was there 102 years and was still serviceable." The old bridge was built in 1902.

The bridge's old swing span was removed Monday, and at about 6:15 a.m. Tuesday, explosives were used to remove two old bridge piers. After the rubble was removed from the river bottom, the new bascule span was floated into place on a barge.

"There has been a steady stream" of people at the public viewing area, railroad spokeswoman Laura Baenen said late Tuesday afternoon. "People have been coming and going. And there have been a lot of cameras."

Baenen estimated 12 to 15 people have been watching from the public viewing area at most times of the day. Some of them are railroad retirees, she said. Public parking is along Bainbridge Street.

The general contractor for the project is Edward Kraemer & Sons of Plain, Wis.

Once it's operating, the west end of the new bascule span will lift into the air to allow barges and other large boats to pass. The old swing span that was removed Monday would swing open to allow them to pass.

The railroad bridge was expected to be closed to train traffic from Monday morning until 7 p.m. today, then to be closed intermittently until 7 a.m. Saturday. While the bridge is closed, train traffic is rerouted onto other rail lines.

The general contractor said last week the river beneath the bridge was expected to be closed to all marine traffic Monday through today, and to be open to marine traffic under 10 feet tall Thursday through Saturday. It said there would be periodic openings for all marine traffic Thursday and Friday between noon and 6 p.m.