IEC 60050-821:2017

Overview

IEC 60050-821:2017, titled International Electrotechnical Vocabulary (IEV) - Part 821: Signalling and security apparatus for railways, is a key international standard published by the International Electrotechnical Commission (IEC). It establishes the general terminology associated with signalling and security apparatus in railway systems, covering both general terms and those specific to related technologies and applications. This edition updates and extends earlier versions to enhance clarity and alignment across the broader IEV series.

As a horizontal standard, IEC 60050-821:2017 supports interoperability and consistency in railway signalling terminology worldwide. The vocabulary is multilingual, including English and French as principal languages, and terms also provided in Arabic, German, Spanish, Italian, Japanese, Polish, Portuguese, and Chinese. This comprehensive approach facilitates international communication and standardization in electrical, electronic, and signaling systems for rail transit.

Key Topics

This part of the IEV encompasses a thorough classification of railway signalling and security apparatus terminology structured into focused sections:

• General Concepts and Terms (821-01): Foundational vocabulary covering overarching principles and definitions in railway signalling.
• Signals (821-02): Terms related to the design, function, and types of railway signals.
• Train Detection (821-03): Definitions addressing technologies and methods used for identifying train presence.
• Operation of Points and Rail-Mounted Equipment (821-04): Terminology for switches, points, and associated operational devices.
• Interlocking and Signal Box Equipment (821-05): Vocabulary covering interlocking principles and control equipment.
• Block Signalling Systems (821-06): Terms related to block control and signalling methods ensuring train separation.
• Level Crossing Protection (821-07): Definitions related to safety mechanisms at pedestrian and vehicle railway crossings.
• Automatic Train Protection and Operation (821-08 and 821-09): Terminology concerning safety systems and automation in train control.
• Communication in Transmission Systems (821-11): Relevant terms for communication technologies supporting signalling.
• Reliability, Availability, Maintainability, and Safety (821-12): Vocabulary focusing on system dependability and operational safety.

Each section offers precise definitions, synonyms, and additional notes, facilitating accurate use of terminology in design, implementation, and maintenance of railway signalling and security systems.

Applications

IEC 60050-821:2017 serves as an essential resource for professionals involved in railway signalling design, installation, maintenance, and regulation. Its applications include:

• Standardizing Communication: Provides a consistent language for engineers, designers, regulatory authorities, and manufacturers involved in railway systems.
• Supporting Training and Education: Assists in academic and vocational programs by providing authoritative definitions related to railway signalling technology.
• Enhancing System Design: Guides the development and documentation of signalling and security apparatus ensuring global compatibility.
• Facilitating Compliance: Helps organizations align with international railway safety and communication norms through shared terminology.
• Improving Safety Performance: Contributes to enhancing safety by promoting clear understanding of complex signalling concepts and security measures.

This vocabulary also supports interoperability initiatives and the modernization of rail infrastructure, underpinning the development of advanced train control and signaling technologies.

Related Standards

IEC 60050-821:2017 is part of the broader International Electrotechnical Vocabulary series (IEC 60050), which organizes electrotechnical terminology across multiple fields. Related standards and parts that complement or support this vocabulary include:

• IEC 60050 Series: Covers other domains such as electromagnetic compatibility (Part 161) and rotating machines (Part 411).
• IEC Guide 108: Defines horizontal standards, under which IEC 60050-821 qualifies, ensuring terminology harmonization across sectors.
• Railway Signalling System Standards: Other IEC and ISO standards that govern specific signalling technologies and safety requirements often utilize terminology from IEC 60050-821.
• National and Regional Adaptations: Various national standard bodies adopt and adapt IEC vocabulary to integrate into regional railway regulations and engineering standards.

For ongoing updates and access to all parts of the IEC 60050 series, users can consult the IEC Electropedia online platform at www.electropedia.org.

Keywords: IEC 60050-821, railway signalling, rail security apparatus, International Electrotechnical Vocabulary, railway terminology, signalling standards, railway safety, train detection, interlocking systems, level crossing protection, railway communication, railway automation, electrotechnical standard, IEC standards