Physics marvel, funding fiasco, and all-around Big Deal

DEEP inside the bowels of Boston's Big Dig, a hard-hatted engineer named George Sarafinas is getting pelted with hundreds of questions – and loving it.

"Will my cellphone work down here?"

"Where will cars that break down go?"

"Are we underwater?"

"Why is the floor so wet?"

The Dig, one of history's most complex construction projects, is 83 percent complete. This ant-farm network of highway tunnels under downtown Boston will replace an above-ground elevated roadway that's become a rickety eyesore.

After years of enduring Big-Dig-induced chaos on city streets and endless reports of cost overruns, Bostonians were invited to walk through one of the tunnels – and finally see whether it will all be worth it. An astonishing half million plus people showed up, many with kids, cameras, and tuna lunches, creating a subterranean parade of humanity that said as much about Boston as it did about the project.

Standing in a four-lane-wide, 1.5-mile-long tunnel that's lined with hundreds of thousands of white and red ceramic tiles, some were positively giddy. "It's just so amazing what you've done," visitor Wendy Valentine told Mr. Sarafinas enthusiastically. "It's so fantastic. Thank you. You all are heroes."

Sarafinas – one of 5,000 workers who've been toiling on the Big Dig for up to 11 years – was thrilled to finally be showing it off. "Isn't this great?" he'd say to passers by.

For the record, cellphones will work when the tunnel opens in December. Stranded cars can pull off into a skinny breakdown lane; overhead cameras will alert emergency crews. And the tunnel isn't underwater, but surrounded by pockets of the water table, which explains the periodic puddles inside. Bilge pumps to purge the water haven't been installed yet.

Standing at the tunnel's deepest point – 120 feet below ground – you can hear a noise that hints at one of the Big Dig's engineering marvels. It's the low rumbling of the Red Line subway train passing overhead.

Above the Red Line's subterranean tube is the Silver Line tunnel. And above that is the passenger lobby for the Red Line. Above that, finally, is the street. All together, it's like an underground mass-transit club sandwich.

To create such a structure in Boston's notoriously squishy soil, engineers had to strengthen the earth by injecting it with millions of gallons of "grout" – a soupy concrete – before carefully beginning to dig.

This and other engineering feats are great sources of price to Bostonians. Where else but Beantown would more than 500,000 people show up for a fluorescent-lit lesson in subterranean physics?

After all, the city of Harvard and MIT is the self-described intellectual capital of the world. It's also home to generations of blue-collar laborers hailing from Ireland, Italy, Cape Verde, and beyond. So the Dig's mix of big ideas and big brawn seems to strike a chord here.

Folks are even proud that the Dig has spawned at least one potential imitator. Seattle is debating whether to replace its aging Alaskan Way Viaduct with a "Puget Sound Big Dig." Estimated cost: up to $11 billion.

But some Bostonians will just be glad it's over – so the city can focus on more mundane tasks. "It'll be nice when they're done," says tunnel visitor Christopher Bergh with a laugh, "so they can come fix the potholes on my street."

The Big Dig is, of course, mostly about tunneling. But here in gritty South Boston, one of the Big Dig's seven "ventilation buildings" juts 18 stories out of the ground.

It houses fans that suck exhaust-filled air from the tunnels and spew it into the sky.

With seagulls soaring between its mast-like smokestacks, the blocky concrete building looks like some kind of next-century warship.

To many who live nearby, it points up some of the not-so-graceful elements of the Big Dig's legacy.

The "vent building" also blocks the view of Boston Harbor from the city's new convention center. Convention officials hope the thing will at least be covered with greenery.

The Big Dig's cost has also long been an ugly issue. In 1991, the estimated price tag was $6.5 billion. Now it's $14.6 billion.

Though the world's big public-works projects typically exceed their estimated budgets – by an average of 28 percent, according to one study – the Big Dig has outstripped them all. The project's overruns of at least 300 percent have spawned charges of corruption and mafia influence.

Fortunately for Bostonians, the federal government is picking up more than half the tab.

But residents of Boston's western suburbs – who don't benefit much from the Big Dig – are grumbling about the recent jump in tolls on the east-west-running Massachusetts Turnpike. They figure their tolls are paying Big Dig bills, while drivers on the Dig's north- and southbound roads get off toll-free.

"So people from the west get stuck paying for this thing, and people from the north and south get a free ride," says tunnel visitor Jim Koschella.

Standing here at street-level, underneath the elevated green highway that snakes through the heart of Boston, you can almost imagine what the city will be like when the Big Dig's grandest promise is fulfilled, and the "green monster," as locals call it, is finally demolished.

The six-lane interstate perched 40 feet above ground will be replaced by a 10-lane subterranean highway. The city will gain 27 acres of open space – and a serious infusion of feng shui.

A leafy tree canopy may replace the skyway's endless rusting green girders, and chirping birds and gurgling fountains may replace the clatterings of the 190,000 vehicles that now cross the "monster" daily.

Perhaps most gloriously, the perpetually pasty residents of this town – where darkness arrives at 4:30 p.m. for four months a year – may get a tad more sunlight as they stroll through the new park space.

In all, what's now an unpleasant walk beneath the belly of a grimy monster may turn into 50 paces of heaven.

But first, Bostonians have to figure out what to do with their new 27-acre treasure.

So far there's little agreement. Some want it to be all parkland. Others worry that a park, deserted at night, would become a den of homelessness and crime. They want development – condos, restaurants, and shops – to keep the place hopping.

This summer the state legislature couldn't even agree on a process to decide the issue. But now, at least, they have a deadline: The entire Big Dig – including the new open space – is supposed to be finished by the end of 2005.