Transcript
Engineering Manual Signals
TMG 1440 REQUIREMENTS FOR THE LOCATING OF UNDERGROUND SERVICES IN THE RAIL CORRIDOR Version 1.3 Issued April 2013
Owner:
Chief Engineer, Signals and Control Systems
Approved by:
Warwick Allison Chief Engineer Signals and Control Systems
Authorised by:
Paul Szacsvay Principal Engineer Signal Research and Development
Disclaimer This document was prepared for use on the RailCorp Network only. RailCorp makes no warranties, express or implied, that compliance with the contents of this document shall be sufficient to ensure safe systems or work or operation. It is the document user’s sole responsibility to ensure that the copy of the document it is viewing is the current version of the document as in use by RailCorp. RailCorp accepts no liability whatsoever in relation to the use of this document by any party, and RailCorp excludes any liability which arises in any manner by the use of this document. Copyright The information in this document is protected by Copyright and no part of this document may be reproduced, altered, stored or transmitted by any person without the prior consent of RailCorp.
UNCONTROLLED WHEN PRINTED
Page 1 of 11
Engineering Manual
Procedure
RailCorp Engineering Manual — Signals — Procedure REquirements for the Locating of Underground Services in the Rail Corridor
TMG 1440
Document control Version 1.0 1.1 1.2
1.3
Date 7 July 2009 11 May 2010 22 August 2012
April 2013
Summary of change Original Approved Issue Application of TMA 400 format; Moved to Procedure folder Document template updated to current version. Technical contents updated to comply with changes to Network Rules and Procedures. Removed text “such as NAR or CSB etc.” from note relating to Uncontrolled conditions. Expanded scope of document to include all CBI areas Defined the meaning of a CBI area
Summary of changes from previous version Summary of change
© RailCorp Issued April 2013
Section
UNCONTROLLED WHEN PRINTED
Page 2 of 11 Version 1.3
RailCorp Engineering Manual — Signals — Procedure REquirements for the Locating of Underground Services in the Rail Corridor
TMG 1440
Contents 1
Introduction .............................................................................................................................4
2 2.1 2.2
Scope........................................................................................................................................4 Purpose .....................................................................................................................................4 Application.................................................................................................................................4
3
Reference documents.............................................................................................................4
4
Terms and definitions.............................................................................................................4
5
RailCorp owned buried assets ..............................................................................................6
6
Non RailCorp Owned buried Assets .....................................................................................7
7
Approval for Cable Locating ..................................................................................................7
8
Access Protocols ....................................................................................................................7
9
Access to Signalling Installations.........................................................................................7
10
Accreditation ...........................................................................................................................8
11
Earthing....................................................................................................................................8
12 12.1 12.2
Controls on Locating ..............................................................................................................9 Locating in CBI Signalled Areas ...............................................................................................9 Locating in Non CBI Signalled Areas......................................................................................10
13
Cable Locating Equipment...................................................................................................10
14
Disconnection of Cable screens / sheaths.........................................................................10
15
Safety......................................................................................................................................11
16
Marking of Services ..............................................................................................................11
17
Interference sources.............................................................................................................11
18
Cable Fault Locators.............................................................................................................11
© RailCorp Issued April 2013
UNCONTROLLED WHEN PRINTED
Page 3 of 11 Version 1.3
RailCorp Engineering Manual — Signals — Procedure REquirements for the Locating of Underground Services in the Rail Corridor
1
TMG 1440
Introduction The need for this procedure has resulted from recent experience where it has been proved that the use of electronic locating devices on underground services may, under certain conditions, affect the operation of the signalling system. As a result of this finding, the use of electronic cable and pipe locators for the purpose of locating underground services needs to be controlled.
2
Scope
2.1
Purpose The intent of this procedure is to define the process by which the location of underground services using electronic locators is conducted within the rail corridor. In the event that infrastructure staff become aware that locating of underground services work is being undertaken by a third party ie contractors, staff shall ensure that the party undertaking the locating work are following the procedures set out below. Where this is not the case, the locating work shall cease immediately and the situation shall be brought to the attention of the Maintenance Signal Engineer.
2.2
Application There is no restriction on the application of this document.
3
Reference documents Railcorp Engineering manual TMG 1310 Locating of Underground Services
4
Terms and definitions The following definitions apply in this document: CBI Computer Based Interlocking. Computer based interlocking systems include SSI, Microlok & Westrace interlocking systems.
Direct Connection Direct connection is the connection of the transmitter output to: a)
An insulated metallic conductive pipe
b)
A cable core, cable screen, sheath or drain wire of a working signal cable
c)
A dead / isolated conductor
Induction clamps These clamp around working cables to enable them to be traced by inducing the locating signal into the cable screen or conductor(s). It is the alternative where a direct connection is not possible Live connection A variation of direct connection is to use a live connector which enables connection to live conductors of cables. The live connector has an isolating transformer to protect the transmitter. The connector and the isolating transformer must have a minimum working rating of 440v.
© RailCorp Issued April 2013
UNCONTROLLED WHEN PRINTED
Page 4 of 11 Version 1.3
RailCorp Engineering Manual — Signals — Procedure REquirements for the Locating of Underground Services in the Rail Corridor
TMG 1440
Induction Broadcast This method is only to be used to find any unknown underground services that may be in the target area as it is too inaccurate for precision locating. Broadcasting is done by the use of a transmitter which emits a signal which is directed into the ground. The transmitter signal couples onto any metallic service / object that may be within the ‘induction zone’ of the transmitter which can then be picked up by the receiver. Cables The signalling infrastructure uses many different types of cables. In broad terms, the cables are either a single or multiple conductor configuration, individually insulated and with an overall sheath for underground installations. Fibre Optic cables may have no metallic content. All cables are predominately PVC insulated & sheathed. Older cables have a copper tape vermin barrier, an outer sheath and a nylon jacket. Newer cables do not have the copper tape vermin barrier and use a PVC sacrificial sheath. There are also other buried cabling systems in use within the RailCorp boundary used by both the electrical and control & communication disciplines. It is not the intention of this document to detail the various types of cable in use however in broad terms the electrical discipline uses a mixture of high and low voltage cables. The Control & Communications discipline uses various cable types ranging from multi pair twisted cable to coaxial to fibre optic. The signalling infrastructure cabling system uses: a)
Mains cables Mains cables are used to reticulate mains power from one track side location to another. Mains cables can carry 415 or 120V AC 50Hz or in some cases, 50V DC. They are typically V75 PVC insulated and sheathed cables with a nylon jacket in either a single or twin conductor configuration.
b)
Main control cables Main control cables run from one track side location to another and are used for the control of the signalling system. These cables are generally a 50 core cable laid in a spiral configuration
c)
Signal & points tail cables Signal and points cables are cables that run from a track side location to individual pieces of ground equipment. This cable is manufactured the same way as the main control cable however it has fewer cores. Modern installations (from 2007 onwards) use a different cable. It is a cable comprising of multiple twisted pairs screened with a drain wire. At some particular locations, due to the higher electrical load of the ground equipment, additional single double insulated cables identical to that used for 50Hz track circuits are used.
d)
Track circuit cables – ‘HiFi’ twin shielded These cables are a twisted pair shielded cable and are run from a track side location to track circuit equipment. This cable is used on all audio frequency track circuits as well as Jeumont Schneider impulse types.
© RailCorp Issued April 2013
UNCONTROLLED WHEN PRINTED
Page 5 of 11 Version 1.3
RailCorp Engineering Manual — Signals — Procedure REquirements for the Locating of Underground Services in the Rail Corridor
e)
TMG 1440
Track circuit cables - Single double insulated These cables are a single double insulated cable that runs from a trackside location to a track circuit. This cable is used on 50Hz track circuits.
f)
SSI Data Cable SSI data cable is used specifically for the interconnection of SSI data link modules. The cable can be identified by its white Polyethylene sheath. The cable itself is comprised of a single pair of twisted red and blue polyethylene insulated conductors.
Controlled Conditions Controlled conditions refer to a requirement that the passage of a train needs to be controlled through the worksite and any locating activities are managed to eliminate interference to train operations. This may mean that cable locating is done in between trains, at the conclusion of trains services for the day or during a possession. Controlled conditions are particularly relevant in CBI signalled areas as a signalling employee may be required to manage the resetting of signalling equipment affected by the cable locating equipment. Uncontrolled conditions Uncontrolled conditions imply that trains are not required to be managed through the work site while cable locating is taking place. This would be the case where the under ground service is in a non CBI signalled area. Note that uncontrolled conditions refer to the cable locating aspect and not worksite protection. SSI Solid State Interlocking A British developed computer based interlocking system using high integrity microprocessor based technology both for the central interlocking (Multi-Processor Module MPM) and for the trackside controls and indications (Trackside Function Modules – TFM’s)
5
RailCorp owned buried assets This procedure has been written with an emphasis on buried signalling infrastructure however it is known that the location of other services within the rail corridor can still affect the signalling system eg communications cables. When locating other services within the rail corridor, the practices and procedures laid down in this document shall be applied. Access to other buried services shall be arranged and conducted in accordance to the instructions and requirements as directed by the asset owner of that particular infrastructure ie access to high voltage cables shall be done in accordance with the instructions issued by the Chief Engineer, Electrical Where there is conflict between this document and the practices, procedures or requirements of another party, an agreement on the process to be undertaken shall be arranged before the work begins. Where this is the case, the matter shall be referred in the first instance to the Signals Maintenance Engineer and if necessary, to the Chief Engineer, Signals
© RailCorp Issued April 2013
UNCONTROLLED WHEN PRINTED
Page 6 of 11 Version 1.3
RailCorp Engineering Manual — Signals — Procedure REquirements for the Locating of Underground Services in the Rail Corridor
TMG 1440
Where the work can’t be done using this procedure, the work shall be undertaken in such a manner so as to not impact either the signalling system or train services ie the work is undertaken during a possession or at the cessation of train services for the day.
6
Non RailCorp Owned buried Assets Within the rail corridor, other buried non RailCorp owned assets exist eg gas pipelines. Where any underground service parallels a RailCorp buried asset by more than 10 metres, (irrespective of the distance between the two services) then it will be necessary to adhere to this procedure.
7
Approval for Cable Locating No cable locating activity shall take place without the prior knowledge and formal approval of the Signals Maintenance Engineer for the area of concern. The approval shall include advice on whether the area of concern is in an SSI area, what limitations on cable locating activities will be required (if any) and whether the work needs to be controlled or uncontrolled.
8
Access Protocols Where the location of underground services is to be carried out, the local Signal Maintenance Engineer or nominated officer is to be notified at least 1 week prior to the work beginning. With this notification the following information shall be supplied a)
Where the work is to be carried out with precise Kilometreages
b)
Names and accreditation details of the staff who will be carrying out the work
c)
Name of the supervising signalling employee (if required)
d)
Whether work will be done on any signalling cables
e)
What methods shall be used during the location work
The Signal Maintenance Engineer or the nominated officer shall approve the proposed cable location activities and confirm whether the work to be performed is inside of an CBI signalled area or not. In addition, the Signal Maintenance Engineer or the nominated officer shall advise what, if any, hazards exist in the area that the group will be working. The term hazard in this context refers to the possible impact that locating of underground services may have on the reliability of the signalling system and its impact on train operations.
9
Access to Signalling Installations Access to signalling installations for non accredited signalling staff presents both an electrical safety risk as well as an operational one and therefore shall be controlled as detailed in the Safety Management system. Under no circumstances shall non accredited persons be permitted free access to signalling locations, housings, cable pits, galvanised steel troughing, or ground level troughing.
© RailCorp Issued April 2013
UNCONTROLLED WHEN PRINTED
Page 7 of 11 Version 1.3
RailCorp Engineering Manual — Signals — Procedure REquirements for the Locating of Underground Services in the Rail Corridor
TMG 1440
Persons requiring access to signalling infrastructure for the purpose of locating underground services shall either be accredited or shall undertake the work under the direct supervision of an accredited signal electrician / signal engineer. Access to cable pits or the like for the purpose of locating of underground services shall be restricted only to qualified locating staff that are familiar with these procedures. Note: The explicit intent of this paragraph is to prevent the unauthorised used of locators in cable pits or the like. Work in confined spaces is detailed in the Safety Management System.
10
Accreditation Accreditation of staff for the purpose of using cable locators on the signalling system shall be done in accordance to the requirements laid down in the Locating of Underground Services reference manual TMG 1310. This document permits four levels of accreditation based on a matrix of connection methods versus signalling infrastructure (SSI or non SSI areas) Where the locating of underground services work is to be done by non RailCorp staff, they shall be accredited to the same level of proficiency as RailCorp staff. Where it is not intended to accredit the personnel to carry out the work, the work shall be done with an licensed RailCorp signal electrician / signal engineer in attendance at all times.
11
Earthing As part of the electronic location of underground services, earthing is required to:a)
Minimise circuit resistance in order to maximise the locator current
b)
Keep the return current path short and away from other underground services in order to minimise leakage current from the target service and to improve the accuracy of the location process.
The earth connection shall be well away from sources that may generate localised earth potential rises such as high voltage power poles, electrical substations or the running rails (which may cause an earth potential rise due to passing electric trains) To reduce the possible hazard of transferring earth potentials, the following manner shall be used to connect the transmitter and earth connection to the service a)
Connect transmitter earth at the transmitter end
b)
Connect the transmitter
c)
If required, connect the remote earth connection
Remote end earths To improve the accuracy of the locating of underground services, it is always preferable but not always feasible, to provide an earth at the remote end of the service being located. Doing so provides a defined circuit in the service being located and greatly enhances the precision of the locate. In some areas, it may be possible to locate using 8 KHz, 33 KHz or higher frequencies without the need for a far end earth by relying on the capacitive coupling of the service to
© RailCorp Issued April 2013
UNCONTROLLED WHEN PRINTED
Page 8 of 11 Version 1.3
RailCorp Engineering Manual — Signals — Procedure REquirements for the Locating of Underground Services in the Rail Corridor
TMG 1440
earth. However this practice generally requires higher output and may increase the coupling to other services. Where remote earths are used, there is the risk of transferring earth potentials. To reduce this risk the following sequence is to be used to connect the remote earth. a)
Connect the transmitter to the local earth
b)
Connect the transmitter to the cable sheath / screen / drain wire
c)
Connect the remote end of the cable sheath / screen / drain wire to earth
d)
Turn on the transmitter
The following sequence is to be used to remove the remote earth a)
Turn off the transmitter
b)
Remove the remote end earth of the cable sheath / screen / drain wire
c)
Disconnect the transmitter from the cable sheath / screen / drain wire
Note: In CBI areas, remote earths shall always be used so as to minimise the coupling onto other services and to reduce the amount of power used to obtain an accurate locate on the service.
12
Controls on Locating Appendix A in TMG 1310 details a map showing the approximate boundaries of all CBI systems on the RailCorp network. In the first instance, this map is to be reviewed to determine if the work to be undertaken falls within a CBI area. In those CBI areas where CBI equipment is directly connected to a cable eg an SSI TFM or Microlok Lamp driver card or input interface card, these systems can be affected by the output signal of an electronic cable locator. As such, the procedures for working in a CBI area as defined in TMG 1310 should be applied. Where CBI systems exclusively use interface relays to connect to field equipment such as signals & trainstops these can be treated as being in a non CBI area and the corresponding procedures in TMG 1310 are to be applied Where work is in a CBI area, close to a boundary of a CBI area or a service runs into a CBI area, the regions’ Signal Engineer is to be contacted to ascertain the appropriate locating procedures.
12.1
Locating in CBI Signalled Areas When locating buried assets in SSI areas, there are limitations as to the frequencies and power levels generated by the transmitter unless train services are managed.
© RailCorp Issued April 2013
a)
Frequencies above 4.1KHz shall not be used
b)
Output power levels shall be 10 watts or less
c)
Direct connection to a cable sheath / screen / drain wire is permitted
d)
Connection of a remote end earth is mandatory to minimise the potential for coupling to adjacent services
e)
Induction clamps are not permitted
UNCONTROLLED WHEN PRINTED
Page 9 of 11 Version 1.3
RailCorp Engineering Manual — Signals — Procedure REquirements for the Locating of Underground Services in the Rail Corridor
12.2
TMG 1440
f)
Induction broadcast is not permitted
g)
Live connection is not permitted
h)
The use of spare cores on a (signalling) cable for the purpose of attaching a locating transmitter is only permitted by those liscensed to do so
Locating in Non CBI Signalled Areas When locating buried assets in non SSI areas, there are no limitations as to the frequencies or power levels generated by the transmitter.
13
a)
Direct connection to a cable sheath / screen / drain wire is permitted
b)
Induction clamps are permitted
c)
Induction broadcast is permitted
d)
Live connection is permitted on AC Mains power cables (reticulating at either 120 or 415 volts) by a person accredited to do so
e)
Live connection is permitted on 50 Hz track circuit cables by a person accredited to do so
f)
The use of spare cores on a (signalling) cable for the purpose of attaching a locating transmitter is only permitted by those accredited to do so
Cable Locating Equipment Cable locating equipment shall be approved for use. The cable locating equipment shall:a)
Be from of a reputable brand of manufacture
b)
Be in good condition
c)
Be within calibration
d)
Any leads used as part of the cable locating process shall be insulated and the insulation shall be in good condition.
When locating in CBI areas, cable locators limited to operating frequencies no higher than 4.1Khz shall be used. Cable locators approved for use in non SSI areas may not be suitable for use in CBI areas.
14
Disconnection of Cable screens / sheaths The disconnection of any cable screen or sheath shall be done safely using the correct PPE and in such a manner so as to eliminate the risk of electric shock. In some instances it may be necessary to remove an insulating barrier such as tape or blind lugs to gain access to a cable sheath or screen. Where the cable screen or sheath was initially insulated and the insulation was removed for the purpose of cable locating, at the cessation of work the screen or sheath shall be insulated to the same or better quality. The use of blind crimps and / or self amalgamating tape is acceptable. The use of PVC insulating tape in this application is not permitted.
© RailCorp Issued April 2013
UNCONTROLLED WHEN PRINTED
Page 10 of 11 Version 1.3
RailCorp Engineering Manual — Signals — Procedure REquirements for the Locating of Underground Services in the Rail Corridor
15
TMG 1440
Safety TMG1310 details numerous hazards that exist on RailCorp buried assets. Prior to any work being carried out, TMG 1310, the pertinent SMS manuals and the local hazards register shall be reviewed so as to identify all known hazards before the work begins. Work shall be performed in accordance with an approved SWI / SWMS
16
Marking of Services Once identified, the ground marking of underground services shall be done using the following colour scheme
17
Hazardous Service Signalling / Communication
Pink
Colour
LV &HV Power Internal & External
Orange
External Telecommunications
White
Gas
Yellow
Water / Sewerage / Drainage
Green
Compressed Air
Light Blue
Fuel, Combustible and Flammable Liquids
Red
Interference sources There are many sources of interference in the railway corridor. These range from the ripple frequency of the 1500V traction system to track circuit frequencies and may be of sufficient magnitude to hinder the locating of underground services. The following ripple frequencies are present in the traction supply: 300Hz, 600Hz, 1200Hz, 1800Hz, 2400Hz RailCorp uses track circuit that use the following frequencies: 50 Hz, various frequencies between 350 & 550Hz, 1700 Hz, 2000Hz, 2300Hz & 2600Hz. RailCorp also uses Jeumont Schneider Impulse track circuits which generate a broad range of frequencies across the spectrum.
18
Cable Fault Locators Some models of electronic locating equipment are also equipped with a cable fault locating mode. Where cable fault locating is required to be undertaken in CBI defined areas, it shall be done in a controlled manner where the effect on the SSI equipment and subsequent train services is managed in the presence of a licensed signalling employee. Cable fault locating in non CBI areas is permitted.
© RailCorp Issued April 2013
UNCONTROLLED WHEN PRINTED
Page 11 of 11 Version 1.3
