This is a photo from WWII taken of an MKT passenger train and a Beech AT7 over Hunter, Texas. You can see the big logo shields on the side of the tender and baggage cars. I located the place as it appears today on Google Earth. A new wye to service a gravel pit.
The track on the left is the old International Great Northern (MoPac) track. Both are still used by the UP today. The photo is facing south west toward New Braunfels and San Antonio. Behind is San Marcos and Austin. The wye just goes into a crushed limestone loading facilty, one of many along the Balcones Escarpment.
If both tracks are still in service, I wonder- Could they use them as double track? How far are they parallel routes? Boxcab E50
Yes, they function as double track. Both lines are still active between San Antonio and I believe as far as Fort Worth. There are many places where they are side by side and have cross overs between them.
I had a feeling if both lines were still in place, they'd use those tracks in that fashion. Boxcab E50
OK, I checked it out a little further. The MoPac line diverges just north of Austin and heads to the north east toward Arkansas. To get to Fort Worth on the MoPac they have to transfer at Valley Junction, just outside of Hearne, to the line from Houston that goes north to Waco. From there it is a "straight" shot to Fort Worth. The MKT continued on to San Marcos then took the MoPac to Waco via track rights where it gained its own tracks again to continue to Fort Worth. So, it is effectively "double track" between San Marcos and San Antonio.
A little off topic, but near San Antonio and all along the route to San Marcos, there are several places where the tracks are just a few hundred feet apart. Most of the road crossings are still at grade level. They are great rail fanning spots, but I don't think the traffic is so heavy on those routes. (Perhaps I don't know when the traffic is heavy along there.)
