Big Dig makes 1st major mark in Artery demolition

The entire mile-long Central Artery through Boston could be removed as early as this spring, Big Dig officials said, as residents and tourists gathered to watch the end of an era and the beginning of a transformed landscape.

"We've been watching this for 14 years, and what they've done in a week is unbelievable," said Diane Bendel, a resident of the nearby Harbor Towers, watching the 60-ton pieces of green steel being carved up. "You can stand at Christopher Columbus Park and see straight through to City Hall."

Matthew J. Amorello -- chairman of the Massachusetts Turnpike Authority, which oversees the $14.6 billion Big Dig -- said that with the demolition "we're getting to see what Boston's going to look like," gesturing to sidewalks and streets bathed in sunlight for the first time in 50 years.

Depending on weather conditions, the elevated structure from Causeway Street to Dewey Square could be demolished by April, Amorello said. The onramp from Storrow Drive near the FleetCenter should be down by May, he said, and the quarter-mile, double-decked segment of Interstate 93 coming into the city is scheduled to be dismantled by July, before the Democratic National Convention the last week of that month.

The last part of the operation will be extracting the temporary support beams for the elevated Artery, which were put underground to support the structure while the Big Dig tunnels were built. Those beams can't be left in place because they prevent the ceilings of the tunnels from being properly sealed and block the way of some utility lines that still need to be relocated.

That means the surface corridor will remain a construction zone at least until Aug. 1, and engineers warn that there may be some leakage in the new tunnels during that process. "The sight lines will be clear, but we'll still be digging," said deputy project director Jack Wright, while a crane lifted a section of the Artery onto a truck behind him.

Workers are cutting up and pulverizing 16 acres of concrete roadway deck and shipping the material -- classified as hazardous because of asbestos, lead, and other contaminants -- to landfills in New Hampshire and Maine. The green steel framework for the Artery, which opened in phases from 1950 to 1956, is deleaded in the places where workers use blowtorches to cut it apart, and shipped to Baltimore for recycling, officials said.

A total of 36,000 tons of steel, 12,500 tons of concrete, and 28 football fields of roadway are being removed, Big Dig officials said. The diversion of traffic through the new southbound I-93 tunnel, which opened Dec. 20, cleared the way for the demolition. Before then, traffic from southbound I-93 and from Storrow Drive was using the elevated roadway into the Dewey Square tunnel.

Although demolition started hours after the old Central Artery was vacated, and a partial view was opened up between Faneuil Hall and the waterfront near Christopher Columbus Park over the weekend, Big Dig officials scheduled yesterday's press conference to celebrate the removal of the last piece of a block-long segment of the roadway, at the foot of the Faneuil Hall North Marketplace building.

The dismantling of the elevated roadway is a plus for the Big Dig, which is billions over-budget and behind schedule. Big Dig officials also scrambled to open the southbound I-93 tunnel before the end of the year, although the last section of the new roadway -- the Dewey Square tunnel, which is being retrofitted to meet modern highway standards -- is still under construction.

The opening of the southbound tunnel turned into an image problem for Amorello because of a proposed $350,000 celebration concert by the Boston Pops. Governor Mitt Romney and top lawmakers criticized the event as wasteful, and it was canceled. Romney also renewed his call to merge the Turnpike Authority with the state Highway Department and thus wrest control of the Big Dig from Amorello.

Yesterday, however, there were few distractions, as Amarello unveiled what he called the ultimate payoff from the Big Dig: the restoration of a 30-acre swath through Boston, for parks and a handful of new buildings. "What do you think?" he asked reporters, as he stood at the foot of Clinton Street where the Artery once loomed overhead. Later, as if on cue, a brief rainshower ended, and the sun broke through, brightening the vista from Faneuil Hall to Long Wharf and the waters of Boston Harbor beyond.

Bendel, the Harbor Towers resident, shared photographs with Amorello of the demolition that she and her husband, John, had taken from their apartment.

Mary Ann Esparo, a resident of nearby Fulton Street, said she was amazed at the view from the base of Faneuil Hall Marketplace across to the long-obscured waterfront and by the fact that "this sidewalk has sunlight on it."

Dan Nuzzo, who lives on Commercial Street in the North End, said he has been going out in the morning and walking around the area enjoying a cigar.

But not all residents are elated. Anne Fanton, executive director of the Artery Oversight Committee, a watchdog group, said many North End residents are concerned that the demolition schedule has been accelerated, resulting in noise and vibration during overnight work.

Pieces of the elevated Central Artery that loom over open-air entrance and exit ramps must be removed in the wee hours to cut down on traffic disruption, said I-93 manager Bill Rogers.

The most challenging section for removal is the spot where the old roadway soars to its highest point, 100 feet, and looms over a portion of the Leonard P. Zakim Bunker Hill Bridge. The onramp from Storrow Drive alongside the FleetCenter also hangs over the base of the Zakim bridge, as well as the spot where the new tunnel for eastbound Storrow Drive traffic joins I-93 south. The new roadways will have to be closed overnight while those sections are removed, officials said. Traffic will be diverted onto surface streets.

The elevated Central Artery network brought traffic from north of Boston and from Storrow Drive into the downtown area and had nearly two-dozen exit and entrance ramps. The structure gradually tapered down and fed into the Dewey Square tunnel through Chinatown, after state officials decided to put that section of the roadway underground.

Hailed as a "highway in the sky," the Central Artery was designed to breathe life into an economically moribund city in the years after World War II.

After the structure is razed, more than a dozen city streets will be reconnected across the old artery corridor. The parcels along the length of the corridor will be turned into parks and new public spaces and, for roughly 25 percent of the 30 acres, new development.

Anthony Flint can be reached at flint@globe.com.