Page 175 - IRSEM_Main Book

7.4.8 Spring Points
(a) Spring points shall be used only in exceptional cases where the same
purpose cannot be achieved conveniently by other means.

(b) Spring Points if used in the facing direction must be fitted with facing point
locks. They may be operated from a Cabin or from a ground lever. In the
latter case, the ground lever shall be of such a type that it will not move
when the Points are being trailed through.

7.4.9 Provision of Isolation

(a) At block stations where trains are permitted to run at speed in excess of
50 kmph, the line on which that speed is permitted, shall be isolated from
all connected lines during the passage of the train.

(b) Such isolation need not be provided at Block stations where trains are
permitted to run at a speed of 50 kmph or below, provided GR. 4.11(2) is
complied with.

Note:- The provisions of Para no. 7.4.9 (a) do not apply to
(i) Junctions where two block section lines meet at the same end of a station and
system of Block Working with adjacent stations on both lines is done by one of the
approved means and the junction is equipped with full complement of signals.

 At such junctions, the First Stop Signal on Single Line sections shall be placed
at an adequate distance from the outermost facing point/fouling mark, the
adequate distance not being less than the sum total of the adequate
distances prescribed in GR. 8.01 in regard to condition for granting Line Clear
and GR. 3.40 in regard to the condition for taking off the Home Signal.
 On Double Line section, the First Stop Signal shall be placed at an adequate
distance from the outermost facing point/fouling mark, this distance not
being less than the adequate distance prescribed in GR. 8.01 in regard to the
conditions for granting Line Clear.

(ii) Block stations where track circuits or other appliances have been provided to
prove whether the connected non-isolated lines are clear or occupied and the
signalling is such that a distinctive aspect is given to the Loco Pilot of a run through
train, restricting the speed to 50 kilometers per hour when a connected line is
occupied.

(iii) Catch and Slip Sidings and Sidings provided for isolation purposes only.

7.4.10 Means of Isolation

(a) Sand humps, trap points, or other approved means of isolation shall be
provided on all goods lines and sidings at their junctions with passenger
lines, the normal setting being such as to prevent the passenger lines
from being fouled.

(b) At interlocked layouts, the means of isolation shall be interlocked with the
relevant signals.

Chapter 7: Essentials of Signalling Page 144 of 535