If you knew where this was you would understand why there are no degrading marks on it. Once I figure out how to post a screen shot of Google Earth I will do my best to indicate where it is located. I don't even know the name of the tunnel. Wish I did.Get on Google Earth and follow 23 north out of Kingsport, TN to Weber City, VA and turn left onto route 614. Once you cross under the tracks you will go a ways further taking another right and cutting through a pass. Now keep following this hwy until you come up on the tracks again. It will cross underneath them but don't cross. Turn right on rt.776 and follow this road until it takes a hard right. Continue following the tracks and you will run right smack into the tunnel.
The Texas type (2-10-4) was a super-power locomotive. It became Texas Pacific's primary freight power in the 1920s resulting in T&P becoming the most efficient freight hauler in the state. These locomotives possessed a beauty and grace unknown to most steam locomotives. It was designed by the master mechanic of the T&P in conjunction with the engineering staff of the Lima Locomotive Works. The T&P gave one of its Texas locomotives to the City of Dallas only to have it seriously vandalized.
This is probably my favorite train. She sure is a beauty!