Page 172 - IRSEM_Main Book

7.2.3 Where inter-signal distance between two signals is less than the distance
required for warning Board, the signals in rear shall either be controlled by the
signal in advance or they shall be combined.

7.2.4 Self-reflecting sheets of approved type or reflectors shall be provided, on the
warning board as per approved drawings.

7.2.5 The warning board shall normally be on the left of the line to which it applies
unless there are special reasons to the contrary.

Section 3: Indication Boards

7.3.1 Indication Boards are provided to give warning to Loco Pilots about changes in
type of signalling or type of Block Working or Automatic Train Protection
Territory.

7.3.2 Where a Block station, which is provided with two aspect signalling without a
Warner signal in rear of the First Stop Signal, is approached from a section
provided with Multiple Aspect Signalling or with two aspect signalling with a
Warner signal in rear of the First Stop Signal, an Indication Board bearing
alternate yellow and black diagonal stripe shall be fixed at not less than
1.4 km. in rear of the First Stop Signal. The Board shall have a legend
"Approaching unwarned Stop Signal".

7.3.3 When a station provided with single line Token block is approached from a
Double Line or a Single Line section equipped with Tokenless block working,
an indication board with a legend "Entering Token Territory" shall be provided
at the First Stop Signal of the station.

7.3.4 Where the block working at one end of a station is automatic and the other end is
absolute, an indication board with suitable legend shall be provided at the First
Stop Signal of the station. The legend on the board shall be “Entering Absolute
Block Territory” or “Entering Automatic Block Territory” as appropriate.

7.3.5 Shunting Limit Board: A Shunting Limit Board shall be provided at Class 'B'
stations over a single line section worked on Absolute Block System where
shunting in the face of an approaching train is permitted and where an
Advanced Starter is not provided. The Shunting Limit Board shall be fixed at a
distance of 180 meters in advance of the First Stop Signal.

7.3.6 Block Section Limit Board (BSLB)

(a) At Class 'B' stations worked on Double Line Absolute Block System (with
multiple aspect signalling) a Block Section Limit Board shall be provided
where there are no points or the Outermost points are trailing.

(b) The Block section Limit Board shall be located at 180 meters in advance of
the Home Signal and protecting the fouling mark of the trailing points, if
any.

(c) The Block section Limit Board or the Shunting Limit Board shall be so
located that the legend is facing towards the station. They shall be fitted
with lamps showing white light in both directions during night or shall be
painted with Retro-reflective type coating.

Chapter 7: Essentials of Signalling Page 141 of 535