[skyscraper]

Originally Posted by PhilliesPhan

While riding on the trolley and the front car of the MFL yesterday from 30th to 15th Street, I had an idea on how a MFL station in Market West could be created with a possibly minimal relocation of utilities and drainage.

For anyone not familiar with the stretch of tunnel from 30th to 15th Street: after the El (or trolley) pulls out, there is a steep incline. This incline progresses until, presumably, the tunnel is under the Schuylkill. After this point, both the MFL and trolley lines ascend.

Another thing to consider is that the trolley line is below the grade of the MFL. This is especially apparent under 15th Street, where the trolleys circle around the foundation of City Hall, under the MFL, and over the BSL. Because the trolley line descends down the incline and passes under the MFL, why not create a new tunnel from the lowest point of the tunnel to 13th and Market? With the aforementioned solution, concrete could be poured on top of the new tunnel, creating a pad for a new bi-level 19th Street Station, with the upper portion for the MFL and the lower portion for the trolleys.

People familiar with engineering: could something like this be possible? I imagine that a solution like this would entail a minimal relocation of utilities and drainage. The only concern might come with the structural support columns of the tunnel.

EDIT: I probably should have posted this in the Transportation forum. Feel free to move that is post if this is the case.

Of course it's possible. Anything is possible. It's just a question of cost.