Page 298 - IRSEM_Main Book

12.14.3 Loose or cracked parts: Switch and lock movements and facing point locks
and bars shall be examined closely to detect loose or cracked parts. Loose or
cracked parts shall be replaced at the earliest.

12.14.4 Cross Slides: In the case of facing point bolt locks provided with cross slides
or plunger detection, there shall be no undue play between the cross slide
and the facing point detector connections.

12.14.5 Testing Switch and Lock movements and Facing Point Locks: Switch
and lock movements and facing point locks shall be given an obstruction test
by inserting a test piece of 5 mm between the switch and stock rails at 150
mm from the toe of the switch. The obstruction shall;

(a) In the case of facing point bolt lock, prevent the lever working the facing
point bolt lock from being latched;

(b) In the case of facing point lock, key type, prevent the extraction of the key; and

(c) In the case of switch and lock movement, prevent the signal governing the
movement over the switch and lock movement from being cleared.

12.14.6 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 later
case, the ground lever shall be of such a type that it will not move when the
Points are being trailed through.

Section 15: Maintenance of Lockbars

12.15.1 Length of Lockbars: The length of Lockbar shall exceed the greatest
distance between any two adjacent axles of any vehicle likely to be used on
the section.

12.15.2 Lockbars shall not be less than 12800 mm long for Broad Gauge and 12200
mm for Metre Gauge and Narrow Gauge lines.

12.15.3 Adjustment

(a) Lockbars shall be so installed that with the operating lever normal

(i) An outside Lockbarlies practically level with the top of the rail.
Note: In new installations, outside Lockbars shall not be used;

(ii) An inside Lockbarlies 38 mm below the top of the rail and the bar does
not lean away from the rail.

(iii) Whenever practicable, the end of the Lockbar shall not be more than
25 mm clear of the toe of the switch, when the points are bolted.

(b) Each Lockbar shall be provided with not less than twelve clips and three
stops located in such a manner that the maximum inter clip distance is
1220 mm. A Lockbar clip shall be fixed as near the end of the bar as
possible but not more than 225 mm.

Chapter 12: Installation, Testing & Maintenance of Mechanical Signalling Equipment Page 252 of 535