AftonMountain tunnel

Monday, January 18, 2010

Afton Mt tunnal,

When railroads in Virginia were beginning to expand to the western part of the state in the mid-1800's, the Blue Ridge mountains stood as a formidable obstacle to their progress. In 1848, construction began on a series of tunnels (Crozet Tunnel being the longest) to link the Shenandoah Valley to the eastern part of the state. The tunnel was engineered by Claudius Crozet, and stands as one of the great engineering wonders of the 19th century.

The tunnel itself is 4281 feet long (that's almost a mile!), and for many years was the longest railroad tunnel in the world, and the longest tunnel drilled without the aid of vertical shafts. When the two ends of the tunnel met on Christmas day, 1856, they were a mere 1/2" out a alignment, an amazing testament to Crozet's engineering skill. The tunnel opened to rail traffic in April of 1858, and was in use for almost a hundred years. In 1944 C&O opened a new tunnel nearby to handle taller freight cars, and the Crozet Tunnel was abandoned.

In the early 1950's, a plan was proposed to use the tunnel for natural gas storage. Two 14' thick walls were constructed within the tunnel, but the project was abandoned before the concrete was completely sealed. There is still plenty of debris from this project left over in the tunnel, such as rusty pipes and paint cans.

The western entrance to the tunnel is a stone arch, about 20' tall by 16' wide. The tunnel is lined with several layers of brick. The top layer of brickwork has fallen from the walls in some places, leaving piles of rubble on the tunnel floor. As you can see from the first picture, there was a layer of fog in the tunnel, which decreased visibility and reflected light from my headlamp back in my eyes. 1500' into the tunnel, the brick lining ends, and from here on the tunnel walls are natural rock. Marks from the hand-powered drills used by the Irish laborers are still visible in places. At the point where the brick lining ends, a veil of water cascades from the ceiling. It was here that Crozet devised an 1800' siphon to carry water away during construction, supposedly the longest siphon ever used.

A short ways after this, the first wall in encountered. Water dripping from the ceiling puddles up against this wall (heading east, the tunnel slopes downhill), and drains through a 24" pipe near the base. The pipe is 16' or so long, and is the only way through the wall. The stretch between the two walls is much like a cave... the floor is rough, jagged rock, and there is a lot of water. There are rusted metal brackets coming out of the floor every 10' or so, I imagine that they were to hold pipes for the natural gas storage project. The echoes at the halfway point between the two walls are simply amazing. Eventually the second wall appears - it has a long, knee-deep puddle of water before it, and yet another pipe to crawl through. This wall is close to the eastern end of the tunnel, so light from the entrance comes through the pipe.

After the second wall, it's just a short walk to the eastern entrance. Water pours from the tunnel walls at one spot, and collects at the entrance of the tunnel, forming another long, knee-deep puddle. The eastern tunnel entrance isn't nearly as attractive as the western entrance, being carved through rock instead of having a stone and brick archway.

Planning is reportedly underway for turning the Crozet Tunnel into a public biking & hiking trail, to be open before 2010. Some funding and land has been secured, but the future of this project is still up in the air. The two concrete walls in the tunnel would have to be removed, the brick lining may have to be repaired or reinforced in places, but otherwise this seems like a great idea. Everyone should have the opportunity to safely see this engineering and historical marvel.

Posted by Pyro at 9:21 PM 0 comments