L1-CHE-SPE-277 TRACK CIRCUIT TYPES CHARACTERISTICS AND APPLICATIONS

Transcription

1 Engineering Specification Signalling L1-CHE-SPE-277 TRACK CIRCUIT TYPES CHARACTERISTICS AND APPLICATIONS Version: 1

2 ENGINEERING SPECIFICATION TRACK CIRCUIT TYPES CHARACTERISTICS AND APPLICATIONS L1-CHE-SPE-277 Version: 1 Effective from: 1 st July 2018 Approval Name Position Signature Document Endorser Louisa Waymouth Manager Standards Approving Manager Phil Ellingworth Chief Engineer Amendment Record Approval Date Version Description 20/06/ Rebadge VRIOGS Track Circuit Types Characteristics and Applications. No change to the technical content. Approving Manager: Chief Engineer Approval Date: 20/06/2018 Next Review Date: 20/06/2021 PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 2 of 21

3 ENGINEERING SPECIFICATION TRACK CIRCUIT TYPES CHARACTERISTICS AND APPLICATIONS L1-CHE-SPE-277 Version: 1 Effective from: 1 st July 2018 PREFACE This Specification replaces VRIOGS Track Circuit Types Characteristics and Applications. The contents of this Specification were prepared by the Victorian Rail Industry Operators Group (VRIOG). This VRIOG Standard has been rebadged as an MTM document due to the retirement of VRIOG Standards as of 30 th June This Specification will be managed under the Engineering Standards Development Procedure (L1-CHE-PRO-032). As documents are uncontrolled once printed, it is imperative to check the currency of the Document on The Depot or the MTM s Document Portal which is available externally at All MTM Standards and Specifications are periodically reviewed, and new editions are published which incorporate learnings and Technical Notes (formerly known as Design Practice Notes). Technical Notes are issued between editions which correct any errors or ambiguities contained in an MTM Standard/Specifications. Standards and Specifications may also be withdrawn and/ or replaced. In the event of conflicts or discrepancies between different types of technical documents, refer to the order of precedence as defined in Chief Engineer s Guideline Engineering Standards Listing (L1-CHE-GDL-005). Note: Any clarification described in a Technical Note or Design Practice Note shall take precedence over the impacted clause or clauses in the associated MTM Standard/Specification. In the event a clause within a Standard/Specification is not achievable a waiver will need to be raised, please refer to the Engineering Waiver Procedure - L1-CHE-PRO-001. Note: MTM does not have the authority to grant waivers on any Standards/Specifications or clauses within a Standard/Specification which relate to Government Regulations or Legislation, e.g. Disability Discrimination Act. Referencing this document Clauses and subclauses of this document should be referenced using the following format style L1-CHE-XXX-YYY Clause Z.Z.Z. Referencing the VRIOGS document number is not required. Approving Manager: Chief Engineer Approval Date: 20/06/2018 Next Review Date: 20/06/2021 PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 3 of 21

4 ENGINEERING SPECIFICATION TRACK CIRCUIT TYPES CHARACTERISTICS AND APPLICATIONS L1-CHE-SPE-277 Version: 1 Effective from: 1 st July 2018 THIS PAGE IS INTENDED TO BE BLANK Approving Manager: Chief Engineer Approval Date: 20/06/2018 Next Review Date: 20/06/2021 PRINTOUT MAY NOT BE UP-TO-DATE; REFER TO METRO INTRANET FOR THE LATEST VERSION Page 4 of 21

5 Victorian Rail Industry Operators Group Standards VRIOGS Track Circuit Types Characteristics and Applications Revision A Issue Date 6/11/2009

6 ii VRIOGS Revision A VRIOGS Track Circuit Types Characteristics and Applications Revision A Issue Date: 6/11/2009 APPROVAL STATUS APPROVER STATUS DATE QUALIFICATIONS Document Developer VRIOG Steering Committee Approved All Sections Accredited Rail Operator Metropolitan Train (Metro Trains Melbourne) Intrastate Train (V/Line) placed in IMS 08/02/2010 Interstate Train (ARTC) Tram (Yarra Trams) For any queries please contact vriogs@transport.vic.gov.au. Any other copy of this document is uncontrolled, and the content may be inaccurate.

7 VRIOGS Revision A iii PURPOSE OF THE STANDARD The Standard has been created through the collaboration of members of the Victorian Rail Industry Operators Group (VRIOG) for the purpose of establishing standards which, if implemented throughout the Victorian Rail Network, will facilitate the interoperability of infrastructure. The use of the Standard is not prescribed by law but, if adopted, conformity with the provisions of the Standard is mandatory in order that the purpose of the Standard be achieved. DISCLAIMER The Standard is published by the Director of Public Transport for information purposes only and does not amount to any kind of advice. Each person is responsible for making his or her own assessment of all such information and for verifying such information. The content of this publication is not a substitute for professional advice. The Director of Public Transport and VRIOG accept no liability for any loss or damage to any person, howsoever caused, for information contained in this publication, or any purported reliance thereon. COPYRIGHT STATEMENT Director of Public Transport This publication is copyright. No part may be reproduced by any process except in accordance with the provisions of the Copyright Act. Where information or material is so used, it should be used accurately and the Standard should be acknowledged as the source of the information.

8 iv VRIOGS Revision A TABLE OF CONTENTS SECTION 1.0 CONVENTIONS... 1 SECTION 2.0 DEFINITIONS... 2 SECTION 3.0 SCOPE AND GENERAL Scope Application Background... 4 SECTION 4.0 TYPES OF TRACK CIRCUITS Track Circuit Types Table of Various Types of Track Circuit Categories... 5 SECTION 5.0 TRACK CIRCUITS DESCRIPTIONS DC Track Circuit DC Coded Track Circuit Relay Coded Electrocode Microtrax Westrak Type TD4 AC/DC AC Feed, DC Relay AC Power Frequency Track Circuits High Voltage Impulse Track Circuit Modulated Audio Frequency Track Circuits Jointless Track Circuit UM FS FS Audio Frequency Overlay PSO III AFO-M SOTC IPI AFTAC II EPIC IIB EPIC IIIC SECTION 6.0 TRACK CIRCUITS EQUIPMENT PROVIDERS SECTION 7.0 REFERENCES... 13

9 VRIOGS Revision A 1 SECTION 1.0 CONVENTIONS 1) Words or phrases that appear capitalised out of context are defined within the Definitions section of this VRIOG Standard. 2) The word Shall is to be understood as mandatory. 3) The word Should is to be understood as non-mandatory i.e. advisory or recommended. 4) Uncontrolled Standards may not be referenced within the VRIOG Standards. These include former PTC Standards, Franchisee Standards, Franchisee Subcontractor Standards and Infrastructure Lessee Standards. 5) Controlled Standards, including Australian Standards and other VRIOG Standards, may be referenced but only if: The referenced item can not be adequately explained with an amount of text that could not reasonably be inserted into the body of the Standard. The reader is not referenced to another Controlled Standard necessary for the item to be adequately explained i.e. one document link only. The referenced document is a Figure or table and could not reasonably be included in the appendices of the Standard. 6) The format employed in the VRIOG Standards is compatible with Australian Standards, and will be used from this point on. 7) The numbering system for the VRIOG Standards is chronologically sequential from the point of introduction, and is not based on any form of interpretive system. 8) The VRIOG Standards contain engineering information necessary to operate a safe Railway. VRIOG Standards will not contain any information that can be construed as a work instruction, procedure, process or protocol. This information forms the basis of each individual entity s Safety Accreditation Certification, and, as such, is outside the scope of VRIOG Standards.

10 2 VRIOGS Revision A SECTION 2.0 DEFINITIONS Terminology used and/or applied in this Standard is defined as follows:- Terminology AC Alternating Current Definition Accredited Rail Operator (ARO) AFO AFTAC II Application for Variation Accreditation DC Double Rail DOT IPI IRJ PSO III PTC Single Rail SOTC TDM Track Circuit A Rail Infrastructure Manager or Rolling Stock Operator who is accredited under Part 5 of the Rail Safety Act Audio Frequency Overlay Audio Frequency Train Activated Circuit II An application to the Safety Director by an accredited rail operator for variation of its accreditation due to the accredited rail operator proposing to make change to or to the manner of carrying out, accredited rail operations that may reasonably be expected:- To change the nature, character and scope of the accredited rail operations; or To not be within the competence and capacity for which the accredited rail operator is accredited. Direct Current Track circuit in which both rails are used for both traction return, and the track circuit. Department of Transport Intelligent Processor Island Insulated Rail Joint Phase Shift Overlay III Public Transport Corporation A track circuit in which one rail is used as a common rail for traction return and the other is divided into sections by means of insulated rail joints. Series Overlay Track Circuit Time Division Multiplexing An electrical circuit where current is carried through the rails and is used to detect the absence of a train.

11 VRIOGS Revision A 3 Terminology Type Approval VRIOG VRIOGS Definition Consideration of form, fit and function under specified conditions to approve equipment suitability for use within VRIOG infrastructure. (Refer to VRIOG Standard for Signalling Design and Documentation VRIOGS , Clause 4.2) The Victorian Rail Industry Operators Group comprising the following members:- VicTrack V/Line Passenger Metro Trains Melbourne Yarra Trams Australian Rail Track Corporation (ARTC) Public Transport Division of the Department of Transport (PTD) Victoria Rail Industry Operators Group Standards Table 1 - Terminology

12 4 VRIOGS Revision A SECTION 3.0 SCOPE AND GENERAL 3.1 Scope This Standard describes the track circuit types, characteristics and applications for use within the Victorian Railway Network. 3.2 Application This Standard applies only to track circuits for both vital and non-vital signalling applications on electrified and non-electrified lines. 3.3 Background The Victorian Railway Network has utilised a number of different types of track circuits for rail track section occupancy detection. This standard describes each type of track circuit, its limiting parameters and its general application.

13 VRIOGS Revision A 5 SECTION 4.0 TYPES OF TRACK CIRCUITS 4.1 Track Circuit Types There are various types of track circuits, its applications and characteristics are categories in the following tables. 4.2 Table of Various Types of Track Circuit Categories Types Track Circuit descriptions can be found in these sections: Direct Current Track 4.1 Direct Current Coded 4.2 Westrak Type 4.3 Alternating Current 4.4 AC Power Frequency 4.5 High Voltage Impulse 4.6 Modulated Audio Frequency 4.7 Jointless 4.8 Audio Frequency Overlay 4.9 Level Crossing Predictors Refer to VRIOG Axle Counter Systems Refer to VRIOG Table 2 Various Types of Track Circuit Categories The Type Approval Register within the DOT Engineering Standards Website contains information regarding the current Type Approval Status of track circuits.

14 6 VRIOGS Revision A SECTION 5.0 TRACK CIRCUITS DESCRIPTIONS The design of track circuit systems are governed by VRIOGS. 5.1 DC Track Circuit These track circuits may only be used in non-electrified areas. For the limitations upon their use in the vicinity of DC Electrified Lines, refer to VRIOG Standard Track Bonding, Track Circuit Connections and Traction Interfaces VRIOGS They require IRJ s to define the extent of the track circuit. DC track circuits are jointed track circuits whose extremities are defined by the use of IRJ s. The preferred method of isolation between track circuits is to provide insulated rail joints in both rails, however in areas of dense crossing work, where the fitting of IRJ s in both rails may be difficult, the use of a common rail between a number of track circuits is allowed. There are two methods of supplying feed energy to these track circuits:- Transformer/Rectifier unit (Rectified alternating current track feed) Battery direct operated (Steady energy DC). For more information refer to ARO setup procedures. 5.2 DC Coded Track Circuit These tracks may only be used in non-electrified areas. They require IRJ s to define the extent of the track circuit. The benefit of using this system over other track circuits is that there is no cabling requirement between the ends of the track circuits. This is achieved through the use of the rails as the communication medium Relay Coded Currently in service but are now obsolete. These are installed on the North East Standard Gauge Line between Donnybrook and Wodonga. Use mechanical code transmitter relays operating at either 120 or 180 pulses per minute. Track relays are tuned to discriminate between 120 and 180 codes per minute, to provide an additional indication from mid-point of single line block to the end of section. This application has been superseded by proprietary integrated electronic code transmitting/receiving units: e.g. Electrocode, Trackcode and Microtrax Electrocode Electrocode is manufactured by GE Transportation Global Signalling. Two different versions of this product are in service in Victoria, these are Electrocode 4 and Electrocode 5.

15 VRIOGS Revision A 7 The main difference between the two different products is the number of codes that can be sent along the track. The Electrocode systems in use in Victoria are microchip based and use Time Division Multiplexing (TDM) to transmit codes along the line. Each code consists of an initial timing pulse followed by a predefined delay for each code then another pulse Microtrax Microtrax is manufactured by Ansaldo STS. The Microtrax is a solid-state, microprocessor-based track and line circuit system. It combines the functions of train detection and line wire circuitry. The track code signal format is AC. This signal is connected to the rails through a Track Interface Panel consisting of a transformer and a heavy current inductor. Impedance is 10Ω at 150Hz and rises with increasing frequency. The Microtrax system is compatible with highway crossing motion and predictor equipment without requiring external blocking units. For more information regarding these track circuits, refer to ARO setup procedure and manufacturer s application data. 5.3 Westrak Type These track circuits may only be used in non-electrified areas. They require IRJ s to define the extent of the track circuit. The Westrak is a type of track circuit used on non-electrified lines using half wave rectification to operate a DC track relay fed from a 50Hz mains or inverter supply. Its use is mainly associated with level crossing protection applications. AC feed and DC relay with both feed and relay co-located. Rails at remote end of track circuit are connected together through half wave rectifier. Relay is low energy unbiased and is energised by resultant half wave rectified AC current. For the limitations upon their use in the vicinity of DC Electrified Lines, refer to VRIOG Standard Track Bonding, Track Circuit Connections and Track Interface VRIOGS This type is generally used in level crossing protection applications to concentrate all equipment in one cabinet at the crossing. In this application, the approach track circuits are fed from a DC to AC inverter co-located with the relays at the crossing. There are several types of Westrak track circuits for general signalling are in service in Victoria:- Westrack; supplied by others. Westrak; supplied by WRSA TD4 AC/DC TD4 AC/DC is a vital track circuit consists of a DC to AC inverter and power amplifier with 4 sets of outputs in a single unit. The TD4 uses a free-running multivibrator, operating at 180Hz, to produce a continuous square-wave which is amplified to produce the proper power and impedance level to feed the track. The resulting AC voltage on the track is about 7V. Because of the transient components of the square wave, there are also high

16 8 VRIOGS Revision A voltage spikes which help to penetrate films of rust between rail and wheel. This voltage will depend upon the conditions of ballast and shunting factors at the time of measurement. The shunting characteristics of the AC/DC track circuit equipment are definitely superior to that of a sine wave source. TD4 AC/DC is manufactured by Harmon Industries. For more information refer to ARO setup procedures and manufacturer s application data. 5.4 AC Feed, DC Relay This variant has been used in country level crossings. Where Westrack type circuits are used for each of the two approach track circuits, the track circuit through the crossing is fed with AC from an inverter provided to drive the Westracks. A DC relay fed through a full wave rectifier completes the circuit. This configuration provides a higher voltage on the rails through the crossing, giving greater shunting reliability and the AC feed provides immunity from false energisation of either of the Westracks. For more information refer to ARO setup procedures. 5.5 AC Power Frequency Track Circuits These are suitable for use on either electrified or non-electrified lines, although they are generally found only on electrified lines. They require IRJ s to define the extent of the track circuit. Modern electronically controlled traction system may generate frequencies that interfere with AC track circuits, consequently these track circuit are not recommended in new designs. AC track circuits use power frequency alternating current at either 50Hz or 25Hz applied to the rails to provide discrimination between the DC traction current and the AC track circuit signal. Note: 25Hz is now obsolete with only a few small line sections still using this frequency, largely dependent on the location power supply frequency. The AC track relays require a local and control supply. The local supply (110V) sets up a reference alternating magnetic field in the relay. The control coil of the relay is connected to the track and is fed by a low voltage AC signal along the track. If this signal is from a supply in phase with the supply feeding the local coil, the two supplies act together to generate a torque on the vane in the relay and cause the relay to pick up. This arrangement, while making the relay extremely selective to both frequency and phase results in a significantly maintenance intensive relay. It also requires that the AC supply to the Track Feed and the relay local coil be from the same supply. The prior suitability of these track circuits for use in DC traction areas led to their use in both double and single rail configurations. Single Rail applications are generally around points and crossing work where the limitation upon their maximum length can usually be accommodated. Double Rail track circuits utilise IRJ s in both rails and require an impedance bond at each end of the track circuit to provide a return path for the DC traction current. For more information refer to ARO setup procedures, Standard Vital Relays Large Plug-in VRIOG and VRIOG Standard Shelf Relays VRIOGS

17 VRIOGS Revision A High Voltage Impulse Track Circuit They require IRJ s to define the extent of the track circuit. These are suitable for use on either electrified or non-electrified lines. Also due to the higher voltage than other track circuit types it is also makes them ideal on lightly trafficked lines, where a significant amount of railhead corrosion and rust may occur. These track circuit systems are supplied by Jeumont Schneider and only single rail applications are in use in Victoria. The most common application is for track circuits over points in electrified areas. For more detailed information regarding these track circuits see VRIOG Standard High Voltage Impulse Track Circuits VRIOGS , ARO setup procedures and manufacturers application data. 5.7 Modulated Audio Frequency Track Circuits These are suitable for use on either electrified or non-electrified lines. These track circuits operate at audio frequencies; (above 1500Hz to approximately 25kHz). The frequency of the nominal carrier frequency is modulated by a lower frequency to provide significant immunity from interference from harmonics generated within the traction system. These track circuits do not require the installation of IRJ's to limit the extent of the track circuit. They utilise either the limited transmission capability of the track to limit the extent of the track circuit beyond the receiver or, where a more accurately defined limit is required, use a tuned shunt (electric joint) to restrict the extent of the track circuit. For more information, refer to ARO setup procedures. 5.8 Jointless Track Circuit There are several types of jointless track circuits for general main line signalling are in service in Victoria. These utilise an electric separation joints between each track circuit to constrain the extent of the propagation of adjacent track circuits. UM71 manufactured by CSEE (Preferred system.) FS2500 supplied by WRSA (In service but not preferred) FS3000 supplied by WRSA UM71 The UM71 track circuit system is suitable for mainline sections and turnouts. Consecutive track circuits are required to have 600 Hz separation to ensure correct operation of the electric separation joints FS2500 The FS2500 is suitable for the same applications as the UM FS3000 The FS3000 can be used in both straight rail applications and through points. For more information regarding each of these products refer to VRIOG Standard Audio Frequency Jointless Track Circuits (Vital) VRIOG , ARO setup procedures and manufacturers application data.

18 10 VRIOGS Revision A 5.9 Audio Frequency Overlay Audio Frequency Overlay (AFO) operates in a similar manner to Jointless Track Circuits however with the benefit being able to work in unison with existing train detection methods. The extent of these track circuits is generally ill-defined and consequently they are not appropriate for most signalling applications. In general, an AFO track circuit is composed of a transmitter, receiver, and associated receiver relay. In the case of a highway crossing island circuit, a transceiver and relay are present. Transmitter, receiver, and transceiver require a DC power supply for operation. They are suitable for use on either electrified or non-electrified lines. There are several types in use within the Victorian Railway Network:- PSO III AFO-M SOTC IPI AFTAC II EPIC IIB EPIC IIIC PSO III The Phase Shift Overlay III (PSO III) track circuit is used to supply track occupancy information for crossing warning systems, as well as other train control systems. PSO III is supplied by WRSA AFO-M A vital modulated audio frequency track circuit (AFO-M) which can be "overlaid" on a non-audio frequency mainline track circuit for use in level crossing approach applications in a mainline power signalled territory. The reach of the track circuit beyond the feed or relay is undefined but is understood to be approximately 100m. AFO-M is supplied by WRSA SOTC Series Overlay Track Circuit (SOTC) is an adjustable length audio frequency track circuit intended primarily for obtaining release of electrically locked points (through a normally de-energized external relay) by occupying the main track immediately ahead of the points. SOTC is supplied by WRSA IPI The Intelligent Processor Island (IPI) is a non-vital track circuit, generally used in sidings for indication purposes. IPI is supplied by WRSA.

19 VRIOGS Revision A AFTAC II The Audio Frequency Train Activated Circuit II (AFTAC II) is a vital overlay track circuit designed to replace existing DC circuits that are controlling warning devices at a highway/railroad grade crossing. AFTAC II is manufactured by Harmon Industries EPIC IIB The EPIC IIB is a vital overlay track circuit manufactured by Harmon Industries EPIC IIIC The EPIC IIIC is a non-modulated audio frequency track circuit for non-vital application. EPIC IIIC is available in seven standard frequencies ranging from 8.2 khz to 20 khz. EPIC IIIC is manufactured by Harmon Industries. For more information regarding each of these products refer to ARO setup procedures and manufacturers application data.

20 12 VRIOGS Revision A SECTION 6.0 TRACK CIRCUITS EQUIPMENT PROVIDERS Track circuits are provided by a number of different industry suppliers. A variety of track circuits may have the same characteristics and each must comply with VRIOGS Engineering Standards and have Type Approval by the ARO.

21 VRIOGS Revision A 13 SECTION 7.0 REFERENCES The following documents have been referenced for the preparation of this standard:- No. Ref No. Title 1. VRIOGS Standard for Signalling Design and Documentation 2. VRIOGS Vital Relays Large Plug-in 3. VRIOGS Audio Frequency Jointless Track Circuits (Vital) 4. VRIOGS High Voltage Impulse Track Circuits 5. VRIOGS Level Crossing Predictors 6. VRIOGS Axle Counter Systems 7. VRIOGS Shelf Relays 8. VRIOGS Track Bonding, Track Circuit Connections and Traction Interfaced Table 3 - References