The last remnant of the old Market Street Elevated, a fixture in West Philadelphia for 100 years, is gone, its pillars toppled last week like dominoes.

An army of ironworkers, carpenters, electricians, mechanics, painters, masons, plumbers and crane operators is now rushing to erect the final stretches of the new El by Monday morning, when some semblance of normalcy is supposed to return.

"This intersection is vital. It has to be reopened," said Jeffrey D. Knueppel, SEPTA's chief engineer and assistant general manager, standing at 63d and Market Streets, where the usual car traffic has been replaced by construction rigs and cement mixers and orange buckets filled with some of the 28,000 bolts used on the final spans.

The intersection is in the midst of a 16-day closure, the final major disruption for a neighborhood that has been disrupted for years by the $710 million rebuilding of the two-mile-long Market El.

Local businesses have been bankrupted and local residents have been inconvenienced, rerouted and displaced by a project that seemed as if it would never end. The work is $300 million over budget and two years behind schedule.

But, finally, the finish may be in sight.

Workers have put up the final 22 concrete spans atop individual concrete columns, replacing the pillars and latticework of steel that was the old El. An American flag flies over the last span at the Millbourne end of the El, erected by ironworkers as the traditional "topping-off" marker.

About 1,000 feet of new spans were put up at 48th and 49th Streets, and 600 feet at the Millbourne end.

By the end of last week, crews were laying new rail and pouring concrete to close the "zipper" openings between spans.

Crews with cranes were working to adjust by several inches the new span that connects to the stone Millbourne abutment.

And the eight-foot-high steel girders holding up the spans are getting a fresh coat of paint, a hue imaginatively named SEPTA Blue.

By Monday, trains will again operate between the 46th Street station and 69th Street Terminal in Upper Darby, but work will continue on the new brick station at 63d Street, where the ghostly skeleton of new platforms is taking shape. The 63d Street station is slated to open in May or June.

Weekend closures on the El will continue until Thanksgiving, as crews finish work on the tracks and at the new stations.

"We're trying to minimize the impact on people, but it's not easy, because the work is invasive," said Kevin O'Brien, manager of the project. "It's been tough on businesses."

Shuttered stores line the work zone, and pedestrians have to negotiate sidewalks closed by chain-link fences to reach businesses that remain open, like the Forman Mills clothing warehouse and the CVS drugstore at 48th Street.

"I haven't been able to get to my street for a month," said a woman who identified herself only as "Lil of Dearborn Street." She said she had to take circuitous routes around the work zones to get to her home just north of Market Street.

Robert Wilson, 18, said the biggest inconvenience for members of his family was the closing of the El during the construction. They have to catch a shuttle bus to 40th Street, where Market-Frankford subway service resumes.

Market Street itself is to reopen in the fall, after city work crews paint lane markers and erect traffic signals, Knueppel said.

For now, though, Market Street remains a military-like staging area for the work overhead: giant cranes to lift 160-ton spans, trailers full of tools and equipment, bags of powdered grout, Pandrol clips to secure the tracks, steel plugs drilled from support plates. About 200 workers at any one time are on the job, and work continues through the night, under the glare of high-intensity lights.

When the Market El work is finally completed, much of the Blue Line - the Market-Frankford Subway-Elevated - will have been rebuilt since 1990.

The Blue Line, the city's busiest, carries 47 million passengers a year over the 13 miles between 69th Street Terminal and the Frankford Transportation Center in Northeast Philadelphia.

"This is such a big player in the regional economy. This is the workhorse. To know that it's strong and vital, that's a big deal," said Knueppel, who began his SEPTA career 20 years ago working on Market El repairs.

The rebuilt Market El should be good for the next 75 years, he said.

The contractors for the final stretch of rebuilding are PKF-Mark III Inc., of Newtown; Cobbs Creek Constructors, of Philadelphia; Ray Angelini Inc., of Sewell; and Devine Brothers Inc., of Philadelphia.

Market-Frankford Line: By the Numbers

Length: 12.9 miles.

Riders: 47 million per year.

Built: 1903-08 (Market Street); 1914-22

(Frankford extension).

Cost: $18 million (Market Street); $13.2 million (Frankford extension).

Began regular service: March 4, 1907.

Stations: 28 (1 closed for reconstruction).

Fare: $2 cash, or $1.45 token.EndText