Thursday, November 16, 2023

1850 3,118' (950m, 0.6 mile) C&O Canal Paw Paw Tunnel near Oldtown, MD

West (Geographic South, upstream) Portal: (Satellite, 1,782 photos)
East (Geographic North, downstream) Portal: (Satellite)

GAPtrail
This tunnel is part of a trail system that goes between Pittsburgh and Washington, DC.
[This is the east (geographically north) portal.]
Construction began in 1836. "The tunnel lining is made of over six million bricks [actually, 5.8m [CanalTrust]] that have stood the tests of time and weather since the tunnel’s opening in 1850....Contentious labor disputes, slow progress (just 12 feet a week), a six-year work stoppage, worker injuries, a cholera epidemic, and mounting debt nearly bankrupted the developers, and even so, the project totaled close to $850,000, some 20 times the original budget....The tunnel was abandoned when the canal shut down in 1924.  The federal government purchased the tunnel in 1938, and performed significant rehabilitation in 1956, 1979, 2007, and 2018."
[Because of rockslides, 2021-23 should be added to the list of rehabilitations. There is a 1.5 mile Tunnel Hill Trail that goes over the 375' (114m) ridge.]

Chesapeake & Ohio Canal National Historical Park posted two photos with the comment:
That’s not something you see every day!
If you visit the Paw Paw Tunnel (mile 155.2) during the winter months, you will notice that it looks different from other times of the year. In preparation for colder temperatures, park staff board up the south portal of the tunnel to preserve the internal masonry of the structure.
During the colder months, chilly winds and freeze-thaw cycles can damage the internal brick masonry. But the plywood boards of the closure act as a windbreak to help prevent this! 
The tunnel is still open to the public and can be accessed via the “doorway” through the boards. Visitors are reminded to please dismount bicycles within the Paw Paw Tunnel and on boardwalks and to follow any directions on signage. (SS)
Photos by Kyle Spencer | The Paw Paw Tunnel windbreak in November 2023
Lindsay Swepston: Location of this tunnel? How long is it?
Chesapeake & Ohio Canal National Historical Park: Lindsay Swepston The Tunnel is located at mile 155.2 and 3,118 feet long!
Dennis DeBruler: Lindsay Swepston The west (south) and east (north) portals, respectively:
Ryan Horst: Chesapeake & Ohio Canal National Historical Park is the North side of the tunnel accessible now from being closed due to rock slide damage/reconstruction?
Chesapeake & Ohio Canal National Historical Park: Ryan Horst Yes! The Tunnel and boardwalk are fully open since the completion of the rock scaling project the end of this summer.
James Stark: Chesapeake & Ohio Canal National Historical Park mile 155.2 of what, Potomac?
Dennis DeBruler: James Stark Miles along the towpath from Washington, DC. https://www.nps.gov/choh/planyourvisit/conditions.htm
1

2

Mark Lakata commented on Photo 1
about 20 years ago

This shows the bends in the river that the tunnel avoided. Note the long cut in the ridge north of the east portal.
Satellite plus Paint

The length of almost a kilometer is even more impressive when one considers it was built with just gunpowder, picks, shovels and wheelbarrows. Progress was just 12' (3.7m) per week. [pbs] Drills and better explosives, let alone Tunnel Boring Machines (TBM) had yet to be invented.
pbs

Nicole Dixon, Aug 2019

"But if you plan to visit, bring a flashlight. Even on the sunniest of days, the openings at both ends of the tunnel reduce to pinpoints as you make the 20-minute walk through the center of the tunnel. You will be able to see and experience a number of features inside the tunnel. You can feel the rub along the fence railing where the tow ropes burned into the wood as the mules dragged the boats along the water below. You can also find other features such as weep holes -openings left in the brick liner to allow for water drainage; rub rails - wooden planks fastened to the brick liner to protect the tunnel liner; and brass plates - these mark every 100 feet of distance and the location of the tunnel's vertical shafts." [mdmountainside] The tunnel is named after the native Paw Paw trees (Asimina triloba) that grow in the area.

The tunnel is 24' (7.3m) high. [BerkeleySprings]

The tunnel saved building 5 miles (8km) of canal. "When traffic finally did travel through the tunnel, it often resulted in bottlenecks, as turning or passing was impossible. Boats would light a red lantern on the stern and a white lantern on the bow so other boats would know which way it was traveling, and boats headed downstream would yield and back out of the tunnel. On one occasion, neither boat would yield and the stand-off lasted for a few days until workers started a fire upstream to ‘smoke’ them out."
[CanalTrust] The tunnel saved building a canal through canyons with steep rock walls, but it was the last thing to be completed on the canal.

nps
Rehabilitation began in Aug 2021 after the trail was closed in Sep 2020 because of "potentially unstable conditions observed in the rock mass during." The canal trail reopened in Aug 2023. The contractor provided a shuttle service when it was using the Tunnel Hill Trail to haul material. There had been a rockslide in May 2016, and some stabilization work was done in 2017-19.
[I had come across sources that predicted it would be open in the Summer of 2022. I wonder what problems they encountered that delayed it to late Summer of 2023.]

I wonder if more rock was moved making the cut on the east end than the tunnel itself. I used Google Earth to try to find some lighting that showed the cut. I noticed that after the canal left the river valley while going upstream, it first went between a couple of ridges, then it cut into a ridge and then it tunneled under that ridge. 
Google Earth, Apr 2008

nps_closure
The grade on the upstream side is 1 in 9 or 11.1%, and the grade on the downstream side is 1 in 11.5 or 8.7%.

CanalTrust_5facts, “Paw Paw Tunnel Interior,” by Randy Miller
Because of the difficulties of building this tunnel, the canal ended at Cumberland instead of the originally planned Pittsburgh. "The pawpaw tree is common throughout the Eastern United States and is a fairly useful plant. It can eaten and can also used as an insecticide. In the past, Native Americans used its fibers to make ropes, fishing nets, and other materials. According to Dr. Karen Gray, volunteer historian for the C&O Canal National Historical Park, the name of the tunnel was associated with a Potomac crossing in the area that dates back to colonial times." As with several tunnels, some people think the canal is haunted.
[But several sources do recommend taking a flashlight because it gets very dark in the middle of the tunnel. In fact, it sounds like one might want a second, backup, flashlight.]

The tunnel is at the elevation of the canal on the upstream side. I wondered how many locks were needed on the downstream side to attain that elevation. So I checked a topo map. I was prepared to count contour lines, but it appears that the locks are marked on the map. So four locks were needed in this area. Note that the B&O and Western Maryland also used the Potomac River valley.
1900 Paw Paw Quad @ 62,500

The above topo map reminds me that the original route of the B&O followed the curves of the river. In 1914, the B&O built the Magnolia Cutoff that tunnels through the fingers of land rather than go around them.
1951 Paw Paw Quad @ 24,000

The Western Maryland was built later and they used a lot of tunneling from the beginning. There are tunnels between each of these bridges.
Andrew Coblentz comment via Dennis DeBruler




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