TramStore21 Report Building sustainable and efficient tram depots for cities in the 21st century
Electricity Supply Above the Tracks
© TramStore21, 2012
Contents Contents ..................................................................................................................... 2 Contacts of TramStore21 Partners ............................................................................. 3 Introduction................................................................................................................. 4 Applications by the partners ....................................................................................... 5 Blackpool Council ................................................................................................... 5 Le Grand Dijon........................................................................................................ 8 RET....................................................................................................................... 17 STIB ...................................................................................................................... 20 External applications ................................................................................................ 25 Railway Technical Web Pages.............................................................................. 25 Bordeaux System.................................................................................................. 26 Recommendation ..................................................................................................... 28
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Contacts of TramStore21 Partners This is a list of resource people responsible for this issue within TramStore21 partnership. The resource people are your experts in this field. They can work within your organisation or at another local authority of your country or can be your consultant.
Name
Organisation
Department or Function
E-mail
Fernand van de Plas STIB
Department of Rolling Stock, Drawing Office
[email protected]. be
Jean-François Colinet
STIB
Department of Tramway, Technical Department – In charge of technical equipment new depot Haren 2 + Marconi
[email protected]
Lode Schildermans
STIB
Direction of Infrastructures – Project Manager
schildermansl@stib. irisnet.be
Daniela Kirsch
Fraunhofer IML
Department of Logistic
Daniela.Kirsch@iml. fraunhofer.de
Henning Schaumann
Fraunhofer IML
Department of Logistic
Henning.Schaumann@ iml.fraunhofer.de
Ludovic Soleil
Keolis
Director Project Tramway
[email protected]
Phil Bowman
Blackpool City Council
M&E Coordinator
Philip.Bowman@ blackpool.gov.uk
REM de Tender
RET
Project Manager
[email protected]
Dick Huybens
RET
Technical Engineering Office Project Manager
[email protected]
Introduction This issue is about several existing pantographic systems currently used and the handling of power supply inside the depots. It analyses the supply in- and outside the depot. The document describes the systems and demonstrates their respective advantages and disadvantages. Different forms of electricity supply, like the supply inside the track (Bordeaux system), are also being discussed.
Figure 1: View of the rooftop1
1
BOGESTRA, Bochum Depot Engelsburg, Photograph taken by STIB
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Applications by the partners Blackpool Council Description The existing system uses a combination of side and centre support poles, generally at a distance of 30 m between poles on a straight track. The bracket arm and tie wire steelwork together with the OLE hanger components are stainless steel. Bracket arm construction embodies fully rated double insulation, with a composite insulator moulded into the hanger body and another at the pole end of the bracket arm. The top tie wire includes a fibreglass loop insulator at the pole clamp.
Key figures The existing contact wire is 80.6 mm²; it is grooved wire on the main line and round wire in the depot. However, following review, the contact wire will be replaced and upgraded to 120 mm² CU AG (Copper Silver). This full replacement of the contact wire will be complete by Easter 2012. The single contact wire is secured by fixed termination. It is not tensioned and is therefore subject to some movement under certain conditions. The nominal height of the contact wire is 6.0 m, with a minimum of 5.85 m and a maximum of 6.2 m above rail level. The amount of stagger permissible on the contact wire is dependent upon the alignment of the track, the curvature, the cant of the track, the wind conditions experienced in Blackpool and the movement of the trams. In consideration of these factors, the normal stagger of the wire is generally limited to 75 mm in either direction about the theoretical centre line; this can, however, raise to 200 mm in either direction due to the effect of the wind conditions.
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Figure 2: Contact wire and tram
In addition and at the same time as the replacement of the contact wire, it is envisaged that the section insulators will also be upgraded. It is anticipated that the industry standard will be adopted using purpose built SI’s with skids. The skids allow smoother dynamic passage of pantographs, reducing the effect of bouncing, subsequent arcing and damage to the insulator and pantograph. It is proposed to use a 0.6-1 KV DC Section Insulator for trolley and pantograph trams as manufactured by Arthur Flury. It should also be noted that Blackpool Council is currently undertaking a programme of catenary support pole replacement, this will again be complete by Easter 2012.
Figure 3: Non double-decker tram and pantograph
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Power supply As previously mentioned, the electrical infrastructure was partially upgraded and renewed in the 1990’s. In addition, two new substations are currently being constructed in preparation for the introduction of new trams. The line voltage is a nominal 600 V DC with a working tolerance between 375 V to 725 V DC. The maximum line current is 800 A. The current system does not have provision for regenerative power from the trams. Also, there is no requirement for regenerative power from the new trams.”
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Le Grand Dijon Description In France, the new generation of LRT trainsets is a low-floored type to allow easy access for handicapped people. This legislation imposed on constructors requires the installation of functional equipment on the roof of the vehicles. The maintenance workshops are consequently equipped with tracks and safety gangways to allow employees to work at a height of 2.20 m. The workstations are also equipped with an overhead crane to facilitate the fixing/undoing and the maintenance of the different equipment installed on the LRT trainset roof. The maintenance tracks are supplied with an overhead line; only the wheel reprofiling system is equipped with its own hauling system. The traction power supply for the trainsets is distributing a continuous current at a voltage of 750 V, in compliance with the standard NF C 50-163.
Figure 4: Detail of the inspection pit at the Montpellier LRT
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Key figures Dijon Chenôve maintenance centre
1 2
3
Figure 5: Dijon Chenôve maintenance center
The three red cycles signify the three divided electrical areas, the blue circles mark the technical installations. The depot is divided into 3 main electric areas linked with the different maintenance and operation activities.
Workshop area Washing area Stabling area
Each area is electrically separated from the others so that a power cut in one of the areas does not affect the others. Each area has its own power supply.
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Figure 6: Electrical substation (Sous-Station)
The electrical power is supplied through overhead lines, which are in contact with the pantographs on the trainsets.
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Insulation of the depot
Figure 7: Electrical separation of the depot and line
The depot is also electrically insulated from the mainline so that it is independent. However, it is possible to connect the mainline to the depot in safety mode to compensate for the loss of traction power supply. Electricity warning lights
Figure 8: Signal shows if there is electricity at the following section
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Warning lights are installed at each entrance of the area in both directions. They inform the train driver if power flows (750 V) and open or block the entrance to the area.
Figure 9: Electricity warning lights
Emergency stop The emergency stop buttons (750 V) are implemented all over the depot in order to cut the power supply if necessary (workshop and stabling area, exterior tracks, caretakers lodge and all risk areas).
Figure 10: Emergency stop
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Workshop
Figure 11: Workshop in Dijon
Each workshop track is supplied by electricity or cut off independently from each other by a traction switch box.
Figure 12: Workshop track
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Traction distribution box (power)
Figure 13: Time delay switches
Time delay switches (normally closed) allow to earth and short-circuit the overhead line and the respective track rail.
Figure 14: Power distribution boxes (for overhead line)
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Neutral Section
Figure 15: Neutral section
The neutral section makes it possible to separate the overhead line of the tracks inside the workshop from those outside. It is also used for interlocking and protection and against short-circuits. Insulating stuck joint
Figure 16: Insulating stuck joint
The insulating stuck joint makes it possible to put the workshop tracks out of use.
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Figure 17: Insulating stuck joint
Access to the gangway and the overhead crane For safety reasons, the access to the gangway is secured by a key system. The operator cannot access the gangway without turning off the corresponding overhead line. To obtain the key authorising the opening of the gate to the gangway, the operator has to follow a special procedure. For more information on this key system, please see issue “Safety and Security”.
Experiences The electric division of a depot into several electric zones avoids shutting down the current of the whole depot if one of these zones must be provided with power.
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RET Description For the newly built depot Beverwaard, RET has designed an elaborate electricity concept. While the stabling area tracks will be equipped with catenaries, the maintenance hall is designed without any catenaries. The tram movement in the maintenance hall will be performed with special vehicles (as shown in the picture below). RET has decided upon this solution among other things for safety reasons.
Figure 18: Vehicle to push the trams on the maintenance tracks at Beverwaard
Key figures There are a number of requirements concerning the catenary of the tramline. Some typical values are presented below. System requirements The projection of cross-span equipment, line interrupters and power supply points is dependent on the electro-technical design of the catenary network and the way in which it is adapted to the provision of outdoor spaces, such as rectifier substations. Substations for rectifiers and switchgear equipment should be positioned as close as possible to the power supply points of the tramline. A multiple system must be applied at crossings, except for contact wires at curves with a radius of less than 50 m. The designs are based on a minimum ambient temperature of -20°C and a maximum of 55°C. The length of the contact wires an d carrier cables amount to a maximum of 750 m. The distance between a fixed and a moveable tensioning fixture must not exceed 750 m. An overvoltage protection is to be provided in the form of a TramStore21 | Electricity Supply Above the Tracks 17
clean grounding electrode fitted with an earth diffusion resistance with a maximum of 5 Ω. The system height is 1.70 m at the point of suspension (distance between the overhead contact wire and carrier cable). The overhead contact wire and the carrier cable are tensioned to a force of 7.5 kN. Support structure Only the standard RET catenary masts that comply with the specified requirements are to be used as support structures. The distance between the centre of the mast to the front of the curb line must be at least 0.65 m. Component requirements The contact wire must have a nominal diameter of 100 mm2. Insulators with a verified value of 3 kV are to be used as standard, tensioning wires in 35 mm2 bronze and line hangers of 10 mm2 bronze 2. Extenders are manufactured from foam-filled-glassfibre reinforced plastic (GFRP) tubing. Requirements relating to electrical insulation The static voltage-to-earth distance taken into consideration should be at least 100 mm and the dynamic voltage-to-earth distance 50 mm. Particular attention is paid to the grounding of engineering structures. • Electrical connections • Requirements relating to bridges • Requirements relating to 600 V power supply and return cables
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The following parameters shown in figure 3 are considered in catenary requirements.
Figure 19: Parameters for catenary requirements
Advantages and disadvantages The energy supply is independent and a back-up system is available. The catenary power supply cables are fairly heavy which limits the usage.
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STIB Description For Marconi depot, STIB has not issued a point of view concerning the catenary design. Haren depot for example has got fixed catenaries, while other depots such as Molenbeek are equipped with flexible catenaries.
Figure 20: Flexible catenary in Molenbeek
Key figures Catenary wire Currently three current cable sections are in use: 100 mm², 120mm² and 150 mm². The standardisation is actually implemented to a cable section of 120 mm². The current cable is composed of a copper-silver alloy with 0.1% silver (CuAg 0.1, specification in accordance with EN 50149). This current cable is also specified in the specifications EN 50149 – type “AC” (= circular section). Catenary height In the following table different specifications are given for the heights of catenaries. The catenary is positioned as follows: between 3.70 m and 6.20 m. The height of 3.70 m is needed for the pre-metro (tunnels). The height of 6.20 m is used inside the depots. The average height of the catenaries in operation is 5.70 m. TramStore21 | Electricity Supply Above the Tracks 20
EN 50122-1
§4.1.2.3: Minimum height of contact line: 4.7 m
IEC 60913
§2.1.7: Height of contact lines: - on-site: 4.4 m - outside the depot: 4.8 m
EN 50367
§1: This standard defines the parameters for the interoperability in the field of interaction between pantograph and overhead contact line. §5.1- Table 3: Nominal height 5 m to 5.6 m
KB 1975-12-01
Belgian Police Rules: art. 46.3. The height of a laden vehicle may not by higher than 4 m.
KB 1976-09-15
Belgian Police Rules for passenger carrying vehicles, tram, premetro, metro, autobus, -car : art. 2. Where electrical power is supplied via catenary the height between the tracks and catenary may not be lower than 4.5 m. Except for special transport deviations.
Lateral displacement of current cable (called “ZIG-ZAG”) The application of the ZIG-ZAG displacement depends on: • the width of the pantograph carbon brush • the height of the catenary • the tram fleet performance • the catenary suspension and tension • the track gradient and level. The values applied at STIB are as follows: on straight track: ±30 cm (with respect to the centreline of the track) in a curve: +30/0 (with respect to the gradient. “-“ is the value for the inner curve).
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Experiences In general STIB is monitoring the tram systems annually. The current cable section is measured on wear and tear. The monitoring of the catenary suspension and the pantograph uplift is not performed but it is planned to introduce it in the near future. The network of catenaries is divided into separated electrical networks, separation by section insulators with a neutral zone or airstrip line breakers. The following table shows the applied specifications for monitoring: EN 50119
§8.5.1: The overhead contact line construction shall be checked if the dimensions included in the installation design are conforming. This shall include the control of the correct installation of the switch operating gear in regards to the switch number and status identification and the security of the padlocks, cabinet locks and interlocking requirements. §8.5.1: The overhead contact line construction shall be checked if the dimensions included in the installation design are conforming, including: mechanical clearances, height and stagger, electrical clearances, balance weights installed, movement/offsets of the conductors, measured tensions of fixed termination, overhead line switches operating correctly. §5.2.4.1: The tensile stress of the calculated grooved contact wire shall not exceed 65% of the minimum tensile stress of the grooved contact wire.
BOStrab
§25.6: Catenary wires are only allowed to be worn down to a minimum of cross-section of 60% of their nominal cross-section.
EN 50119
§5.2.1.1: The dynamic performance of the overhead contact line system and pantograph systems shall be analysed in order to anticipate the dynamic behaviour of the overhead contact line, including the uplift of the contact wire at the support and the current collection quality. §8.7.2: The dynamic validation shall be undertaken to ensure the compliance with the performance criteria of all relevant parts including track work, rolling stock and catenary interfaces. If the criteria for measuring by force are not available, the criteria of measuring shall be the loss of contact. Measurable arcs lasting longer than 10 ms (max. 25 ms), it shall only occur once every 100 m.
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prEN50122-2
§10.1: In order to avoid corrosion damage in the return circuit and damage in neighbouring metallic structures, the stray current situation shall be assessed during commissioning and checked during operation. (§10.2.1: recommended method for continuous monitoring of the rail potential).
Advantages and disadvantages The depot is equipped with a fixed catenary. This requires only small maintenance and provides a better power supply. The major disadvantage of this solution is the high installation costs.
Figure 21: Fixed catenary in Haren depot
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Figure 22: Fixed catenary in Haren depot
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External applications Railway Technical Web Pages “Railway Technical Web Pages” offer information about a number of topics concerning train maintenance, including shore supplies. The following articles originate from this homepage: “Where overhead electric traction is used, the overhead wires are usually installed inside inspection sheds but not in shops were vehicles are lifted. If it is necessary to get access to the roofs of trains, the overhead current must be switched off and the switch secured by a lock. Any person working on the roof will have a personal access key for the lock to ensure the current remains off until the work is complete and it is safe for it to be restored. The access stairs to the roof level walkway will also have a locked gate which can only be unlocked if current is off.”2 “In the modern depots built for the Eurostar Channel Tunnel trains in London and Paris, the overhead catenary in the workshops is designed to swing away from the roof when required to allow access to the roof mounted equipment.”3 Another possibility is “a shore supply attached to a New York City subway car, which has a third rail traction system. For safety reasons, the sheds are not equipped with the third rail, so a supply through a long lead is provided. The lead is plugged into a socket on the side of the train. Various systems are used around the world. In the case shown below, the shore supply socket on the car has a knife switch to isolate the current collector shoes from the supply. This is to avoid electric shock risks to personnel working on or near the shoes. In older installations, this facility is not provided and a shore supply will energise all electrical equipment on the train,
2
http://www.railway-technical.com/train-maint.shtml#Shore-Supplies, Shore Supplies,
last visit: 15.06.2011 3
http://www.railway-technical.com/train-maint.shtml#Shore-Supplies, Shore Supplies,
last visit: 15.06.2011
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including the shoes. In these situations, special precautions have to be taken to ensure no "overhead leads" or "stingers" are inserted on a train being worked on.” 4 “For third rail systems, the shore supply cables are usually fed from electrified rails suspended from the shed roof. The cables are hung from trolleys running along the rails so that the supply is available along the whole track. It is common to use the overhead leads to power the train out of the shed until the leading collector shoes are in contact with the current rails outside the shed. This is sometimes called "railing". The train is then stopped and the overhead leads removed. The leading car is then used to drag the rest of the train out of the shed. Care has to be taken to ensure all leads are removed before allowing a train to leave the shed and enter service. In the US, the "railing" procedure is often performed "on the fly" (with the train moving), since the shore supply is connected directly to the collector shoes, which are large paddles. The live end of the "stinger" rests in a hole on the shoe or is clipped to the shoe by a large spring clip.”5
Bordeaux System In the city of Bordeaux the officials decided to partly leave out overhead contact lines in support of the integrated cityscape. This technique is used in the inner city and some suburban areas. The combination of areas where catenaries are installed works frictionless. The same trams run through the whole transport network. The solution is the part-time electrification of the rails, activated by radio frequency communication. Hence, the rails are only electrified in the moment the tram is supplied. This measure ensures the safety of the population and enhances the acceptance of the tram system. The switch between the systems is done by the driver and does not take additional time. In the depot and in the direct surrounding,
4
http://www.railway-technical.com/train-maint.shtml#Shore-Supplies, Shore Supplies,
last visit: 15.06.2011 5
http://www.railway-technical.com/train-maint.shtml#Shore-Supplies, Shore Supplies,
last visit: 15.06.2011
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the trams run with standard overhead power supply. Accordingly the only effect on the depot is the additional maintenance work.6 The costs of such a system can be estimated by a factor of three in comparison to a conventional electricity supply.
6
cf. PTI 2008: Die Straßenbahnen machen sich frei:
source: http://www.uitp.org/publications/public-transport-magazine-BIdetails.cfm?lg=de&iddoc=78&year=2008&month=5, last visit: 15.06.2011
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Recommendations The power supply in the depots and the catenary network outside the depots has to be planned and managed very carefully. The roof area of the trams is entered during maintenance; therefore a functional and safe work routine must be implemented. All partners use overhead wires, which are accessed with pantographs. However the nominal line voltage and the nominal diameter of the contact wire differ among the partners. At RET and Blackpool there is a 600 V line voltage whereas in Dijon a 750 V is the norm. Blackpool has planned to replace all old contact wires by Easter 2012 of 80.6 mm2 with 120 mm2 wires. Unlike Blackpool, RET has a component requirement which says that the contact wire must have a nominal diameter of 100 mm2. In Dijon there are three main electric areas inside the depot: workshop area, washing area and stabling area. Each of the electrically provided areas is insulated, so that in case of a power cut in one of the areas, the others are not affected. Dijon uses a special safety system in the maintenance area. The access to the gangway and the overhead crane for maintenance activities is particularly secured. This ensures that the gangway can only be entered if the power is turned off and the power cannot be turned on again during the process.
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