(15th in a series of posts on Walkability and Bikeability)
John Marquette is a retired librarian/archivist, author, historian, and a resident of Bethlehem. His current project is focused on the restoration of the interior of the Archibald Johnston Mansion in Housenick Park.
The biggest challenges to a pedestrian bridge are a) crossing the Norfolk Southern tracks on the South Side and b) the additional linear footage the bridge and its approaches will require to be ADA-compliant. I think the maximum grade allowed is one foot of elevation per 10 feet of length. (Engineers and architects, please correct this figure.) So, we need at least 26 feet of clearance over the N-S tracks, assuming they grant permission: where’s the drop back down to the south side going to be?
This isn’t a matter of measuring the distance from the Ice House to the Greenway and building a span that length. We have to go up at least 26 feet on each side of the river with a compliant grade.
This makes planning this bridge seem unimaginably costly. Suspending a bridge under the Fahy sounds like a feasible approach, if we base feasibility on the amount of money we have available.
Gadfly wonders a couple things:
1) The City is seeking money for a feasibility study. Who does feasibility studies? Can we assume imagination and creativity as well as the kind of knowledge to solve such engineering problems as John points to? (Gadfly leaves that preposition at the end — “to which John points” — no, yuk.)
2) The PB planning and discussing has some history among the local folk. Were any ideas floated that would be interesting to hear about?
3) I guess the logical spot for the PB is near Fahy Bridge. But were any alternate spots considered? I think I read somewhere that in the “old days” a bridge (or was it the ferry?) went from the Sand Island boat access spot to the Union Station area. So what if the bridge were farther west — would that help with the railroad problem at all?
One thought on “Feasible or not feasible — preliminary thoughts (15)”
I think the usual way to handle ramps for these types of structures is with a helical ramp.