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weaverton Frog Hollow Industrial Track, West Virginia...
The Frog Hollow Industrial track splits off right in front of NA Tower in Martinsburg and runs through town, and south to the Martin Marietta Plant.  This track runs a mile or so, but I only have a few feet separation from Martinsburg. 
I don't know a whole lot about the plant and how it operated, but from photos it appears that boxcars, hopper cars and covered hoppers are used to serve the plant.  It appears that the plant was also called the Capitol Cement Corporation, a division of Martin Marietta.

Below is the map of the Frog Hollow Ind Track.  I oriented the map this way, since that is the way you'd see it on my layout.  You can see Martinsburg's NA tower on the left of the map.  The line heads basically parallel to Queen Street down to what was the Martin Marietta Cement Plant in the Chessie Era. 

Below is my graph paper plan for the Frog Hollow Ind Track.  I do not have room for the balloon track, but can squeeze int he scales and shaker.  The main lines don't run right by the plant, but I don't have the space here for separation.  I may put a backdrop between the two.

Below is my current status of the layout.  ((I haven't started yet, but will post photos when done))