Single Line-
Ø Normal authority to
proceed “OFF” aspect of LSS.
Ø Direction of traffic
established but LSS alone fails-Prescribed Form containing a PN obtained from
the station in advance.
Ø Direction of Traffic
cannot be established (Panel Failure)-LCT (T/D 1425 or T/C 1425)
Ø During TIC for the
Engine sent for opening communication-T/B 912 & T/B 602 with items 1 to 3 deleted, For the
Trains CLCT (T/G 602 or T/H 602)
Ø To enter an
Obstructed Block section-T/C 912.
Double
Line-
Ø Normal authority to
proceed - OFF aspect of Automatic/Semi-automatic/Manual Signal.
Ø Semi-Automatic/Manual
signal fails - T/369(3b)+PHS
During
prolonged failure of Signals when Communication is available-T/D 912