Hello Nimec,
the detectors are not in the Sherman Hill v2 route, they are part of the "Ballast Turn" session. You shoulnd't hear them unless you are running that particular session.
If you don't like them, then remove them in Surveyor (Select "Sherman Hill v2" > "The Ballast Turn" > Edit Session). After removing the detectors, save it with a different, easily recognisable name.
I placed the detectors according to the track diagram published in the August 2012 issue of "Trains Magazine" so, going west from Cheyenne, you can find them:
- approx. 2 miles before Borie Junction;
- just after Borie Junction;
- approx. 1 miles before Granite;
At each location there are two detectors, one on track #1 and one on track #2.