Saturday, August 25, 2012

Comments New York, Pittsburgh and Chicago Route

What is most interesting about the proposed route for the New York, Pittsburgh and Chicago route is that its location had such favorable grades and its location was direct. While the line's curves were not to exceed 4 degrees, that degree curvature is too severe for Higher Speed Rail (HrSR).  So, the proposed location needs today to be looked at from the standpoint of location with 2 degree or less for curves. If the location were considered for high speed rail (HSR) curves should be 1 degree or less

Recently sketches of the map for the proposed NYPC RR with grade profile have been provided to this testplant blog from the Interstate Commerce Commission,  Finance Docket 4,741,  February 27, 1930. It is noteworthy that closer examination finds that at its crossing of the Allegheny Frontal would be a grade of 1.337% for a distance of 7 miles. The line was to use a 1560 foot tunnel. A longer tunnel and / or combination of using the face of the Allegheny frontal to ascend could have lessened the grade. In fact, a five mile long tunnel was also proposed that lessened the grade to .03 per cent.

The steep grade was to have been from Houtzdale to a place about 5 miles northeast of  Tyrone, PA using Emigh's Gap.
Thomas Moran woodcut looking east from Emigh's Gap, published "Pennsylvania Railroad Historical and Descriptive" 1875.
The Pennsylvania Railroad in an apparent competitive contingency to the NYPC RR planned a shorter low grade line across Pennsylvania that today's historians name the "Sam Rea" line after the PRR president who's name is on it. It crossed the Allegheny frontal between Tyrone and a place south of there that was north of Bellwood, PA. It did so with a longer tunnel and but heavier grade proposed by the NYPC RR yet remaining less than 1%.

Both The NYPC RR and "Sam Rea" line would have used dramatic viaducts likely rivaling the one built across the Tunkhannock creek known as the Nicholson Viaduct 1912 - 1915 by the Delaware and Lackawanna Railroad.


See http://www.historicbridges.org/pennsylvania/tunkhannock/photos.htm to learn about the construction of the viaduct with the tools available in 1912.

If the rough location of the NYPC RR were followed across Pennsylvania for a new high speed rail (HSR) line, structures like this one in Germany would be built. A viaduct on this magnitude together with a longer tunnel at the proposed NYPC RR (Emigh's Gap) route over and through the Allegheny frontal would result in a lesser grade.

Check out http://1x1.fi/9130 for more photographs of German high speed rail (HSR) construction in topography similar to Pennsylvania's.

The NYPC RR would have required 19 bridges / viaducts and 35 tunnels. Today, the number would be different due to the ability to create cuts and fills with diesel powered hydraulic construction equipment not possible with woven wire propelled steam shovels, pneumatic drills, dynamite, temporary narrow haul spoil haulage trains, and towers supporting  buckets of concrete on woven steel wires.



2 comments:

  1. Note that for an electric Rapid Rail corridor, keeping the grade very low is less critical than degree of curvature ~ a ruling grade of 1:40, or 2.5% grade, is quite reasonable for electric traction. Indeed, 2.5% ruling grade and 2.5 degrees ruling curvature is a much better speed profile for Higher Speed Rail than a 1% ruling grade and a 4 degree ruling curvature.

    For Express HSR, which is the type of construction shown, short sections of higher grade are often allowed because the HST takes the slope in a short time and, due to inertia, with very little loss of speed. So for short (train length) higher slope sections, the spiral may be the binding constraint, rather than the grade of the slope.

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  2. What's most interesting to me about the route is -- it serves State College!

    The fact that it's straighter and flatter is a side benefit!

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