(1) When line clear has been given, no obstruction shall be permitted in the block section in rear.
(2) When line clear has not been given shunting or obstruction for any other purpose shall not be permitted in the block section in rear unless it is clear and is blocked back.
(3) Shunting or obstruction for any other purpose shall not be permitted in the block section in advance unless it is clear and is blocked forward. Provided that when the block section in advance is occupied by a train travelling away from the station, shunting or obstruction may be permitted behind the train under special instructions taking into consideration the speed, weight and brake power of trains and gradient on the section, and as soon as intimation has been received that the train has arrived at the block station in advance, the line shall be blocked forward if it is still obstructed.
C - Conditions for granting line clear and obstruction at class 'B' Station on Single line