Page 169 - IRSEM_Main Book

(e) For Metro Services, every Multiple Aspect Signal, whether automatic,
semi-automatic, or manually operated which, is required to display
‘Caution’ aspect to a train, it shall normally be placed at an adequate
distance from the next signal in advance. This adequate distance shall not
be less than the maximum emergency braking distance of the trains
running on the section at the maximum permissible speed on the ruling
gradient. Where the adequate distance cannot be provided and the
‘caution’ aspect is being displayed, the next signal in rear shall display the
‘attention/’caution’ aspect. The ‘attention’/‘caution’ aspect shall be
repeated back on successive signals in rear, until the adequate distance is
obtained.

7.1.16 Combined Signals: When owing to their location, it is necessary to combine
any two signals, one Stop Signal only may be provided under approved
special instructions, capable of displaying any or all the following aspects:
(a) Stop

(b) Caution
(c) Attention

(d) Proceed

Note: Under approved special instructions, a colour light Distant signal may be
combined with the last Stop signal of a station in rear or with an Intermediate Block
signal or with a Stop signal protecting a level crossing. (Ref: GR: 3.07(7), G.S.R.
157(E). Dated-05-3-21)

7.1.17 Distinction between Signals:

(a) Diverging Lines: Unless otherwise permitted by approved special
instructions, where two or more lines diverge, a route indicator of
approved design shall be provided.

(i) Route Indicator - The type of Route Indicator to be provided, shall be
as under -
 For speeds in excess of 15 kmph: Direction type Route Indicator for
up to 3 diversions in any side of the main line or Direction Type
Route Indicator with LED Matrix for more than 3 diversions on any
side of the main line.

 For speeds not exceeding 15 kmph: Any Route Indicator of
approved design.

(b) Converging lines: Unless otherwise permitted by approved special
instructions, when two or more lines converge, the signals shall be fixed
on separate posts.

Chapter 7: Essentials of Signalling Page 138 of 535