About 2015 Mod 3 Question 1

[ericyang_thx]

Dear Sirs,

As I studied a control table sample answer of 103A(M), some questions are raised:

1, "Preset 105A(S)" in row 1 under "Special Controls" is to make sure position light 105 shows a proceed
   aspect?

2, In column "Tracks Occ for t" under "Opposing Route Locking", Is that mean 103A(M) can be set even-though
  "BL" is occupied?

Thank you very much.

[PJW]

Dear Sirs,

As I studied a control table sample answer of 103A(M), some questions are raised:

1, "Preset 105A(S)" in row 1 under "Special Controls" is to make sure position light 105 shows a proceed
   aspect?

2, In column "Tracks Occ for t" under "Opposing Route Locking", Is that mean 103A(M) can be set even-though
  "BL" is occupied?

Thank you very much.

The CT isn't quite as I'd have depicted, but

1. Yes because there is a GPL between the entrance signal and the exit signal and in the UK we do not like drivers having to pass signals showing ON, when the route is set and the main signal is "ready to clear" then the GPL is cleared.  Once that has been proved to have been achieved, then the main entrance signal may clear (N.B. NR's rules on pre-set shunts look to be about to be simplified, but this is the essence of the traditional situation).

2. Yes but more than this.  Provided that BL has been occupied for the time stated which is calculated to be long enough that there is high confidence that the train will have come to a stand, then the opposite direction route can be set and its (PL) aspect clear despite the fact that BL is occupied by a rain that had been moving in the opposite direction.

[ericyang_thx]

Dear Sirs,

As I studied a control table sample answer of 103A(M), some questions are raised:

1, "Preset 105A(S)" in row 1 under "Special Controls" is to make sure position light 105 shows a proceed
   aspect?

2, In column "Tracks Occ for t" under "Opposing Route Locking", Is that mean 103A(M) can be set even-though
  "BL" is occupied?

Thank you very much.

The CT isn't quite as I'd have depicted, but

1. Yes because there is a GPL between the entrance signal and the exit signal and in the UK we do not like drivers having to pass signals showing ON, when the route is set and the main signal is "ready to clear" then the GPL is cleared.  Once that has been proved to have been achieved, then the main entrance signal may clear (N.B. NR's rules on pre-set shunts look to be about to be simplified, but this is the essence of the traditional situation).

2. Yes but more than this.  Provided that BL has been occupied for the time stated which is calculated to be long enough that there is high confidence that the train will have come to a stand, then the opposite direction route can be set and its (PL) aspect clear despite the fact that BL is occupied by a rain that had been moving in the opposite direction.

Thank you very much for your reply.