Sunday, July 17, 2011

4. Bessemer - Port Perry Branch - Wilmerding

The curves between milepost 342.1 and 339.2, Bessemer to Wilmerding are severe. The allowable NS passenger  speeds range from 35 to 45 mph. The NS line is in blue.

The yellow line from  Bessemer milepost 342.1 (40.396144N79.848997) to Wilmerding milepost 339.2 (40.394058N79.798025W)  would possibly permit track class 6 speed of 110 mph. It would be more likely  track class 5 permitting 90 mph. It would require a tunnel and / or deep cut. The yellow line is a 1 degree right curve beginning at Bessemer with a straight tangent to Wilmerding.

Alternatively, the orange line, from milepost 340.6 (40.396728N79.832458W) to milepost 339.7
( 40.399203N79.816889) is a 2 degree curve and would permit class 4 track speed of 80 mph.  A lesser cut would be required.

The Port Perry Branch diverges south from the mainline at milepost 339.5. The proposed 2 degree curve would have to be designed not to conflict with the Port Perry Branch. The diverging point could be changed to be further west and beyond milepost 339.7. The new alignment at 340.6 would cross over the Port Perry Branch requiring the construction of a flyover in order not to have a conflict.

From milepost 339.5 ( 40.396222N79.813836W) to 339.2 (40.393806N79.808617W) another orange line represents a 2 degree curve that would ease the existing 4.8 degree and 3.3 degree combined curve requiring a 45 mph passenger speed and 35 mph freight speed. This would permit track class 4 and 80 mph. Its construction would have an impact upon the former Westinghouse Air Brake manufacturing facility at Wilmerding, PA.

Either of these concepts would likely require significant environmental  review.

See 49 CFR 213.17 for Federal Railroad Administration Track Safety Standards information.

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