My question, I live on CSX mainline in NC and know that when I see green or yellow signal that I can expect activity in the near future. I noticed that on several occasions on NS that I have seen green signal back to back, alsdo this was on single track. I quess my question is how do NS signals compare to CSX.
you were on single track abs signal if the signals were green back to back nothing was around. on abs system when a train goes by a positive signal say west bound all signals for eastbound movement will drop to restricting back to the positive signal for east bound movement. on trailing moves it will go to yellow after the rear of train passes next signal.
On single track TCS or the signals are green both sides, except for the signal prior to a control point which would be yellow, until the dispatcher selcts a route. Once he/she selcts the route,say Westward, the oppossing Eastward signals drop to red. As the train progresses Westaward the signals will be Red for the block the train occupies. The next block to the rear will be yellow and the second block to the rear will be green. This provides two blocks spacing between following trains. The Eastward signals will clear from red to green as the train clears the blocks to the rear. Once the train clears the single track section, if no other routes are selected the signals will go back to their back to back green configuration.
J/Terry thank you for the info.