I am thinking that this photo is the original 1854 era Portage bore where AR Loop swings in, and that the Galitzin and Allegheny bores were not in existence yet, as the Horseshoe was still not constructed, and the State System Muleshoe line to Holidaysburg, Petersburg was the original mainline
Tunnelhill side view of separate twin bores, each being single track tunnel(s) with tunnel fans (now removed). The middle swing track was to send trains down opposite routes in case of derailment, or a passenger shortcut run around. Baldwin Centipede helpers, shove a freight uphill through the Galitzin bore, on the Tunnelhill side
The Allegheny bore was the second constructed tunnel, and was single tracked, until the recent double stack crown mining, widening it to 2 tracked
The 3rd constructed tunnel was the single tracked Galitzin tunnel, which is now cinder blocked up
L to R, Portage, Allegheny, Galitzin bores, from Tunnelhill side
L to R, Galitzin, Allegheny bores, from Galitzin side, both originally single tracked
Construction of the third tunnel, Galitzin bore ... It is a mystery ... How was the Allegheny tunnel originally double tracked ... then single tracked ... then recently double tracked ? I am guessing that rolling stock was narrower, allowing tightly spaced double tracks ?
Clearly marked UN Tower, but it looks like the location of AR tower ?
Perhaps it is prior to the Galitzin single track tunnel construction ?