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CNTP - Tunnel 24


Tunnel 24

South portal with gravel and dirt mix 'road' approaching on former railroad grade.

Photo taken by Alex Wood in August 2012


BH Photo #243757


Tunnel 24 was bored in 1878, and carried the CNO&TP/CS through the mountain at Nemo, Tennessee. A small depot was located south of the south portal. Beside the depot, was a switch to the Morgan & Fentress Railroad. On top of the portal once stood two homes. There was also a height brush about 1000ft from the portal, to warn any brakemen on top of the cars (a 1800's practice) that there was a low clearance approaching. Today, all of the above listed are gone. The homes, depot, and M&F Railroad are all gone. M&F's tracks were pulled after a 1949 flood destroyed their bridge over the Emory River. In 1963 CNO&TP successor and lease holder Southern Railway began moving forward with plans to eliminate, bypass or raise the remaining 10+ tunnels on the CNO&TP. Due to increasing rail car height, the 15X20 measurements were not generous enough and posed restrictions on shipments on this vital rail corridor. Plans were drawn up to bypass 24, and Nemo sister tunnels 23 and 22 with two new tunnels. The alignment of such may be viewed on the Google Map. The new tunnels are 20X30, much larger than the old tunnels. Today, the tunnel sits empty beside the new 24, which Southern Railway successor and lease holder Norfolk Southern uses daily. It is almost completely intact, with minor damage being a collapsed, but cleared, north portal. The interior sees minor water buildup on the south end, however dries out half way through. For years off roaders have enjoyed the tunnel, and it is quite neat to explore if you're a history buff. The current owner of the tunnel is not known, as Norfolk Southern has the current tracks well over 700 feet from this tunnel, however some are not sure if it was possible for Southern to get rid of a tunnel the City owns.


Tunnels through Nemo Mountain on Former railroad grade
Morgan County, Tennessee
Completely intact, except for fallen north portal (seperated from tunnel bore), has not carried railroad tracks since 1963.
Bored in 1878 during the construction of the Cincinnati Southern Railway, a railroad wholely owned by the city of Cincinnati, Ohio. The contracts were given to the CNO&TP, the lessor of the rail line, to finish the tunnels.
- Cincinnati Southern Railway (CNTP)
- Cincinnati, New Orleans, & Texas Pacific Railway (CNO&TP; CNTP)
Tunnel #24 is bored through a mix of shale, limestone, sandstone, slate and clay. Therefore, the tunnel is fully lined with stacked limestone masonry and a brick masonry roof, which at one time had a thin concrete covering that has since eroded. The portals are completely limestone, and the position numbers of the stones relating to stone placing on portal curve are still visible.
Total length: 2,174.0 ft. (0.4 mi.)
Deck width: 15.0 ft.
Vertical clearance above deck: 20.0 ft.
Eligible for the National Register of Historic Places
Also called
Nemo Tunnel 24
Cincinnati Southern Tunnel 24
Approximate latitude, longitude
+36.06704, -84.65241   (decimal degrees)
36°04'01" N, 84°39'09" W   (degrees°minutes'seconds")
Approximate UTM coordinates
16/711421/3993934 (zone/easting/northing)
Quadrangle map:
Inventory number
BH 54665 (Bridgehunter.com ID)

Update Log 

  • December 1, 2012: New photo from Alex Wood
  • November 29, 2012: Updated by Luke Harden: Added categories "Cincinnati, New Orleans, & Texas Pacific Railway", "Cincinnati Southern Railway", "Railroad"
  • November 29, 2012: Added by Alex Wood


  • Alex Wood


CNTP Tunnel 24
Posted September 22, 2013, by Alex Wood

That may have been changed later on, or the information on that page could be incorrect. Norfolk Southern still classifies (the few) units under CNO&TP ownership as "CNOTP" under the cab numbers. Also, this image from 1901 shows the reporting marks as "CNO&TP". None the less, "CNO&TP" is the general name the line is referred to by rail enthusiasts, employees of Norfolk Southern and local historians. I would appreciate the titles of these articles covering these tunnels should be left under the name "CNO&TP" as the author saw fit.

My original intention was not really to name the articles based off AAR or ICC reporting marks, but rather, what the tunnels are commonly listed under by those respective groups in making the articles more easily accessible and noticeable to those looking for information on them.



CNTP Tunnel 24
Posted September 16, 2013, by Luke Harden (lukemh9 [at] gmail [dot] com)

According to this list of AAR reporting marks, the reporting mark CNTP


CNTP Tunnel 24
Posted September 15, 2013, by Alex Wood

Excuse me, but to whomever renamed ALL of my posts to "CNTP", please stop. That is not the proper initialized name of the railroad and looks unprofessional. The proper initialized name (reporting marks) are "CNO&TP" as per ICC classification set in 1879.