In the above map, I looked at elevation values near the Culver Viaduct in Brooklyn which is the concrete elevated structure that runs from south of Fourth Avenue and 9th Street to north of Carroll Street and Smith Street. I used ARCGIS 10.1. I brought in a subway stop file from several years ago and through a spatial join, I was able to assign the nearest elevation available near a subway station. The problem with the elevation file is that most of the points given are at street level but others are the heights of structures, such as the viaduct itself, the expressway that goes over the canal and so on. As far as coding is concerned, both street elevations and structure elevations are coded the same so I can not tell them apart. Since I do not know how the height of a structure is defined, I would believe that the Transit Authority's official height of the Smith and 9 th Street station will not match mine. Nevertheless, it would be interesting to look at the map anyway. In the map, the white numbers are heights above sea level and comes from a contour height file. The color dots are either street elevations or the elevations of a structure, however they are defined. Here are my observations:
- The 15th Street - Prospect Park station on the F and G lines is underground but the height assigned is 200 feet. The nearest heights around the station are in the 132 to 249 feet range. but the contours show values around 164 feet. My reading may be a mistake.
- The 7th Avenue Station which is underground is listed as 100 feet.
- The 4th Avenue Station on the F and G routes is above ground the the elevation is listed as 60 feet. Heights around the station as street level is around 40 feet with a sharp downward slope towards the water. The structure is is rising at this point as one goes westward.
- The Smith and 9 th Street station is listed at 90 feet which is the height of the structure. At the surface, which is at the canal, the heights are a few feet.
- The viaduct takes a sharp turn here and decends downward towards the Carroll Street station. The Carroll Street station is underground and is listed as 50 feet. These are the values at street level in the area.
It is interesting to note that the 7th Avenue station which is underground is 40 feet higher than the open air Fourth Avenue Station and 10 feet higher at street level than the very high Smith and 9th Street Station. Now you know why Park Slope is called Park Slope.
This material is not official and was an experiment. To be verified. Tramway Null(0)
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