Saturday, August 18, 2012

High Line PRR Proposal Juniata Valley

In 1907, a proposal was made to build a "high line" in the Juniata Valley from Petersburg, PA to Clark's Ferry, PA where the Juniata River joined the Susquehanna River. The "high line" then followed the east bank of the Susquehanna River to Rockville, PA north of Harrisburg. At Rockville the "high line" would have joined the mainline. The "high line" was proposed in part to address increased traffic. Additional capacity was required. Track capacity could be added to the mainline or this new line could have been built.

The "high line" connected with the the Petersburg Branch and the mainline at Petersburg, PA.  At Petersburg, the Blue Juniata River meets the Little Juniata River forming the Juniata River. Petersburg is located southeast of Tyrone, PA and north of Huntingdon, PA. In 1907 a branch railroad from the mainline at Petersburg followed the Blue Juniata River west to Hollidaysburg. The Petersburg branch at Hollidaysburg, PA joined the Hollidaysburg and Portage branchline that scaled the Allegheny frontal south of Altoona and the mainline. The Hollidaysburg and Portage branchline to Gallitzin, PA and the mainline there followed a line originally built by the Commonwealth of Pennsylvania to bypass the incline planes and levels of the Allegheny Portage Railroad in 1854. The line was sold to the PRR and dismantled in 1858. ( The line was surveyed and built by civil engineer Milnor Roberts who later was responsible for the construction of the Northern Pacific Railroad.) The line was rebuilt as the Hollidaysburg and Portage branchline in 1896. By 1900 earlier extensions east of Hollidaysburg along the Blue Juniata River completed a line from Gallitzin to Hollidaysburg to Petersburg. This became the alternative route over the Allegheny frontal using a smaller "muleshoe curve" to carry the line over the frontal. West of Hollidaysburg near Duncansville a branchline ran north to Altoona from a junction called the "Wye" switches. the Hollidaysburg and Portage branchline, or as the PRR would have designated, the H and P secondary, was built to move coal eastward together with the the Petersburg branch relieving the mainline of the additional traffic. 

The "high line" proposal was named as the line was to be built higher upon the sides of the mountains above the Juniata River. The line would have had eased curvature in comparison with the mainline alongside the Juniata River. The section through the Lewistown Narrows east of Lewistown would have been built upon Shade Mountain with its unstable talus rock formation. It is not known if the PRR decision to not pursue the construction of the "high line" was due to the stability of the Shade Gap Mountain talus field or not. It was probably a major consideration.

On the eastern end of the proposed "high line" a tunnel would have been required through Peters Mountain between the east bank of the Susquehanna River across from Clarks Ferry and north of Rockville.

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