To hear the champions of Philadelphia's university district tell it, the west bank of the Schuylkill is poised to give Center City's skyline a run for its money.

Last week, Brandywine Realty Trust announced plans for its third riverfront skyscraper, a sharply faceted, 47-story office-and-apartment tower at 30th and Walnut Streets. West Philadelphia office space now commands higher rents than the aging behemoths in the city's legacy downtown. Such is the clamor to live close to the big campuses that at least five residential high-rises are in the works.

It's nice to see the city's skyline stretching west. But a clutch of shimmering skyscrapers do not a neighborhood make.

Overlooked in all the hoopla over Brandywine's latest project, FMC Tower at Cira Centre South, are the conditions on the ground. The site is cut off from the Schuylkill waterfront by a large, triangular moat, which looks down on the train tracks that feed into 30th Street Station and is one of several barriers that make walking there an unpleasant, and often hair-raising, experience.

The gauntlet is a vestige of a time when the west bank of the Schuylkill was a dumping ground for the city's most undesirable uses, from a slaughterhouse, which stood north of 30th Street Station, to the Schuylkill Expressway. But as the area has found new life as a research and innovation district, it has become valuable real estate. At 650 feet, FMC will be the tallest building in West Philadelphia - the sixth tallest in the city - and the focal point for a major population cluster.

FMC, designed by Pelli Clarke Pelli and BLT Architects, will house 260 apartments. Evo, the latest name for the 33-story luxury dorm that Brandywine is erecting at the north end of the block - also part of Cira Centre South - will have space for 850 students. If you combine the future office workers in FMC and the current occupants of the IRS (located next door in the former post office), the total daytime population on the two waterfront blocks swells to almost 7,000. That doesn't take into account the thousands who walk past those sites every day on their way from Center City to the universities and hospitals.

What those pedestrians experience as they enter West Philadelphia over the Walnut and Chestnut Street bridges is not pretty. They must first brave the speedway of Schuylkill Avenue, which functions as a long on-ramp for I-76. Once safely across, they are greeted by tall metal security fences that guard the moat, to protect the high-voltage electric wires below from vandalism.

The fences have always been an unsightly gateway, but soon they will also obscure the ground-level views of FMC and Evo. The two buildings should serve as the beachhead in the formation of a West Schuylkill neighborhood, projecting a sense of habitation and activity. The highways and fences make their job more difficult.

There is a solution, of course: Build a deck over the tracks.

Why there, you might ask. The city is full of places that have been isolated by highways and train lines, Penn's Landing probably the most notorious. The construction of the Vine Street Expressway drove a fissure through Chinatown and ruined the forecourt to the Free Library.

While all these wounded fragments in the city's grid deserve attention, there are compelling reasons to focus on West Schuylkill. Beyond the large number of people affected by the poor sidewalk conditions, the gaping moat is preventing the full integration of the city's two most important economic engines, Center City and the university district.

A deck over the open triangle would immediately transform Schuylkill Avenue from a dismal highway to a riverfront promenade. Properly landscaped, the deck would become an extension of Penn Park: Think of it as the next phase in a greenway linking the train station and Penn.

The deck could be more than a park, however. If it were designed to support a structure, even a small one, it might be possible to camouflage the gloomy floors of Brandywine's garage between the two towers - a real blight on the emerging west bank skyline. 

It's a shame that a conversation about how to cover the moat didn't take place earlier, as part of the planning for FMC and Evo, so they could be equipped with street-level uses facing the river. Both buildings plan to have only limited retail space. Without distinctive public uses on the ground floors, these glass towers, like the others going up in West Philadelphia, are more likely to feel generic and placeless.

No doubt, such decks, even a relatively small one like this, are expensive to build, more so here because of the complexity of spanning the electrified tracks. Yet, unlike Penn's Landing - another worthy candidate for a deck - this is a place where private investment is already taking place. Brandywine is spending half a billion dollars on FMC and Evo, designed by Erdy McHenry. It's only natural for public infrastructure improvements to follow.

The discussion is finally beginning, driven by Drexel University, which recently acquired rights to develop the rail yards north of the train station. As a first step, Drexel will commission a feasibility study to explore how the decks over the tracks could be constructed and financed. Even though the block with FMC and Evo is not Drexel territory, it will be included in the study, university president John Fry promises.

Brandywine will test the concept next year, when it begins work on a $3.7 million pocket park north of Evo on the east side of the post office building, which the company renovated for the IRS.

To make that sliver of land usable, Brandywine will cap the narrow air shaft between the building and the sidewalk. The state contributed $2 million to the project, which promises to dramatically change the way we experience Schuylkill Avenue.

PennDot also is promising improvements, including wider sidewalks and bump-outs at the intersections, to make crossing easier.

With greening projects planned on Market Street - at the Porch and the IRS building - the continuous riverfront promenade from the train station to Penn doesn't seem so far-fetched. Right now, there is just one missing piece.