Page 203 - IRSEM_Main Book

Section 2: Indian Railway Standard Drawings

8.2.1 Signalling and Interlocking Drawings - IRS (S) & Notation

(a) Indian Railway Standard Drawings, designated by the code word I.R.S. have
been issued by the Director-General, Research Designs and Standards
Organisation, Ministry of Railways, Lucknow. The signal drawings are marked
IRS (S) -"S" stands for "Signal". The particulars of the drawings and their
reference numbers are detailed in an "Index of Indian Railway Standard
Signalling and Interlocking Drawings - IRS (S)". This index shows all the
IRS (S) drawings arranged alphabetically, as well as serially, in the order of
their numbers. Each drawing number is either prefixed with letters 'SA' or
letter ‘S’. 'SA' stands for a signal assembly and 'S' stands for a part of a signal
assembly.

(b) New designs and drawings which are accepted for adoption as standards
have the word "Advance" suffixed to their number e.g. S-8716 (Advance),
pending their final adoption as Indian Railway Standard Drawings. For such
drawings the manufacturers shall have a sample approved by the
purchaser before undertaking the bulk manufacture.

(c) Supply of Standard Drawings

RDSO drawings available on RDSO website, shall be referred as and when
required. However, a set of RDSO drawings shall be maintained in the
office of Sr.DSTE/Dy.CSTE, DSTE/ASTE and by each SSE/JE as required.

Section 3: Standard Specifications

8.3.1 Indian Railway Standard Specifications

(a) Indian Railway Standard Specifications - Specifications for materials used for
signalling purpose are issued by the Signal Directorate, Research Designs
& Standards Organisation, Ministry of Railways, Lucknow and are titled as
"Indian Railways Standards Specifications". These specifications are issued
under a fixed serial number e. g. S-12-54, the letter "S" denoting "Signals"
the number "12" representing the serial number of the specifications and the
final number "54" indicating the year of original adoption as standard, or in
the case of revision, the year of last revision. IRS/RDSO specifications are
available on RDSO website.

(b) Other Specifications: Specifications issued by national/international standards
bodies like Bureau of Indian Standards, British Standards Institution,
CENELEC (European Committee for Electrotechnical Standardization), IEC
(International Electrotechnical Commission), ASTM (American Society for
Testing and Materials) International, DIN (German Institute for Standardisation)
may also be referred for signalling purposes, where required.

Chapter 8: Drawings & Specifications Page 170 of 535