Page 470 - IRSEM_Main Book

Annexure: 19-A1 (Sheet 2 of 3)

S.
Guidelines for Signal Sighting - For shifting of existing Signals/erection of new Signals
No

1 Factors to be considered for Locating a signal
(a) Please refer to Para no: 7.1.13, 7.1.14 of SEM for placement of Signals.

(b) A Stop signal shall be avoided (as far as possible) in risky location, where Train will
stop on steep gradients/Girder Bridge/viaduct/Culvert/Cutting/Obstruction to
Road/Theft prone area/vicinity of chemical factories.

(c) Minimum visibility in MACLS territory: Distant signal: 400 meters, Stop signal: 200
meters. Please refer to Para no: 7.1.11.
(d) Height of normal aspect of the Colour Light signal shall be approximately at 3.65
meter.

(e) No external light shall dominate a signal aspect. If it can not be resolved, proper
screen shall be provided behind the signal unit to improve contrast.
(f) Intermediate block signal shall be located, so as to split block section into near
halves. It shall not be provided in a Block section with heavy and continuous
falling gradients steeper than 1 in 80 unless the brake power of trains on the
section is adequate to enable the trains being stopped at IB Signal.
(g) Automatic signal shall be located normally with a spacing of one km from each
other subject to other considerations and headway required. It shall not be
provided in a Block section with heavy and continuous falling gradients steeper
than 1 in 80 unless the brake power of trains on the section is adequate to enable
the trains being stopped at each of the Automatic Stop Signals.
(h) Any signal, if proposed on Right Hand side, requires prior approval of Competent
authority. Right Hand signal shall be provided with a retro reflective type of arrow
to indicate the line to which it pertains to.

Note: (i) Till a signal is brought in to use, signal unit shall be turned away from
direction of Traffic. No testing of signal aspects shall be done in the face of
an approaching train, by turning signal towards direction of Traffic.
(ii) when a signal is not in use, it shall be distinguished by two crossed bars (X)
across it, each bar being not less than one metre long and 10 cm wide. (GR
3.18)

(iii) Signals not in use shall not be lit. (GR3.18 (3))
(i) When signals are going to be in close proximity, they may be combined as per

Para 7.1.16.

(i) 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)

(ii) Where proposed IB signal location and a mid section Gate are in proximity,

IB signal shall be so located, to protect LC gate also.

Chapter 19: Installation, Testing & Maintenance of Signalling Equipment Page 416 of 535