Page 303 - IRSEM_Main Book

(b) Signal arms shall be kept securely fastened to the spectacles casting and
maintained at the correct level when in the 'ON' position.

(c) Signal arms shall be kept clean and properly painted.

(d) It shall be ensured that spectacles are securely fixed on their spindles or
studs, bearing brackets are firmly attached to the post and back light
blinders are in their correct position.

(e) Arm spindles or studs and counterweight lever connections shall be oiled
regularly and kept working freely. It shall be ensured that counterweights
are in their correct position and firmly secured and that the lock nuts on
adjustable joints are tight.

(f) Spectacle roundels or glasses found loose, cracked or broken shall be
attended to and replaced promptly.

12.21.2 Slotting

(a) Where signals are slotted, any of the controlling agencies shall be
independently capable of returning the signal to 'ON'.

(b) When a Warner arm is placed below a Stop arm, the slot lever shall be
installed so that the Warner cannot be taken 'OFF' unless the Stop Signal
above is at 'OFF'. When the Stop Signal is returned to 'ON', the Warner
shall return to 'ON'.

12.21.3 Shunt Signals: Where a Shunt Signal is placed on the same post as a main
line signal, it shall be placed not less than 2.5 meters below the main arm.

12.21.4 Balance Levers: Where practicable, balance levers shall be placed out of reach
from the ground and parallel to the line. Counterweights shall be securely
fastened to the levers and safety bolts provided at the end of the levers.

12.21.5 Back Lights

(a) Indications: Except when the front light can be seen from the Cabin or
interlocking frame location, back lights of mechanical signals shall show a
white light when the arm is in the 'ON' position and no light in any other
position.

(b) Warner Signal Fixed green light: The fixed green light of a Warner
Signal shall also show a back light.

(c) Distant Signals: Distant Signals in multiple aspect area shall show two
back lights in the 'ON' position and no light in any other position. However,
where electric lighting of Distant Signals is provided, the Distant Signals in
Multiple aspect area may show atleast one back light in the 'ON' position if
the arrangement is such that the bottom light is lit only when the arm is
displaying the 'attention' aspect.

Chapter 12: Installation, Testing & Maintenance of Mechanical Signalling Equipment Page 257 of 535