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The nine-mile Dubai is the first tramway in the world to feature a ground-based power supply system Reducing the overheads throughout its length. HYWELL WATERS/SYSTRA.

ramways and systems have historically sourced much Do away with equipment of their power from overhead Tline equipment (OLE). However, and urban tramways become a much over the last two decades, catenary-free operations have rapidly grown in popularity. more attractive proposition, says SYSTRA They avoid the need for visually obtrusive OLE equipment in city centres, allowing extremely successful and has been adopted Midland Metro’s fleet of 21 Urbos 3 historical features to remain visible to in other areas of including , is currently being retrofitted by residents and visitors. , Orleans and . CAF with lithium-ion cells, so that OLE There are other advantages to catenary- APS has been adopted around the world can be dispensed with on four planned free running, including reduced cost and - it was installed on the which, sections of the network - including through time associated with design and approval upon opening in 2014, became the first Birmingham’s central Victoria Square and in of the system, expedited stakeholder tramway in the world to feature a ground- City Centre. acceptance, enhanced climate resilience, and based power supply system along its entire The batteries will be fitted to the roofs of more flexibility for rolling stock design as length. SYSTRA managed the design of the the trams and recharged by OLE on other headroom is not limited by OLE equipment. first phase of the Dubai Tram and is in the sections of the route. Recharging is also There are several technology options process of undertaking preliminary design possible through a ground-level power for catenary-free operation. The choice for its second and third phases, in association supply in stations. for a given tramway is influenced by the with AECOM. Fitting out the entire 21-tram fleet is length over which catenary-free running System Engineering Manager at SYSTRA, estimated to cost £15.5 million, and further is required and the characteristics of the Mathieu Melenchon reflects: “We are costs will be incurred to replace the batteries section on which the catenary-free solution very proud that SYSTRA has played an once they are life-expired. will be rolled out. The solutions can broadly instrumental part in making this innovative However, according to Midland Metro be split into two categories: systems based technology real. The challenge now is to find owner the West Midlands Combined on a continuous power source delivered a way to make the costs comparable with Authority, the decision will save more than through a contact line embedded in the traditional systems. This is something we are £9m in infrastructure capital costs while also improvements such as distance between and (potentially) a hydrogen production between the University of Birmingham trackbed; and vehicles equipped with working on.” protecting architecturally sensitive areas charging points and the time between facility, which further increases overall and Porterbrook and between on-board energy storage from batteries, There are three principal ways of providing of both Wolverhampton and Birmingham. upgrades and replacement. system lifecycle costs. The lack of hydrogen and Eversholt which are in the process of and hydrogen fuel cells. on-board energy storage - batteries, The metro system continues to provide an Supercapacitors are an alternative way distribution infrastructure makes this the constructing standard gauge hydrogen- For continuous ground-level power supply supercapacitors and hydrogen fuel cells. The effective alternative to the private car, helping of providing onboard energy storage, and most costly solution compared to classic OLE powered trains. systems, power is provided by physical first, battery storage, is applicable closer to to ease congestion and support economic can be charged much more quickly than systems, but economies of scale could be Other rolling stock owning companies and contact or by induction. SYSTRA selected home, with Midland Metro set to become the growth. batteries. However, they have less capacity to achieved if a local transport authority also manufacturers are offering hybrid units that the Alstom APS supply system for the first system in the country featuring sections Research and development in batteries hold charge, meaning they are more suited to chose to migrate its bus fleets to hydrogen can operate using a combination of diesel, pioneering catenary free system installed without OLE, and relying on battery power is also being supported by the automotive lines with short distances between stations fuel cells. Furthermore, the UK commitment electrical and battery power. in in 2003. This system has been in carefully selected areas of the region. sector, which could help yield significant where charging points can be located. to achieve ‘net zero’ greenhouse gases by Derek Small, from SYSTRA, adds: “There CAF Urbos 3 trams use this technology 2050 means cost is not the only factor to be is no definitive answer to the catenary- to run on catenary-free sections of the tram considered. free question. It comes down to careful The 41-mile utilises a ground-based sections of line with large distances networks in the Spanish cities of , Currently, across the globe, only the consideration of many factors to determine supply system to reduce visual intrusion in the city’s between stations and where speeds Seville and Cadiz. Chinese company Sifang is developing a which of these solutions is most appropriate UNESCO Heritage Listed centre. SYSTRA. can be considered high (greater than Lifecycle costs for systems hydrogen-powered tram which will have - client drivers location, route, demand, 50kph, or 31mph).” tend to be higher, owing to the need for a top speed of 70kph (43.5mph) and will environmental impact must all be considered, Costs can be higher than classic larger substations. be able to carry 380 passengers. The tram and you can’t treat any one of them in catenary systems but the catenary-free Hydrogen fuel cells produce power is being designed to take three minutes to isolation. It’s a bit of a balancing act but approach offers several advantages. from hydrogen and air using electrolysis. refuel and will have a range of 100km. simply looking at cost is probably the wrong “In Bordeaux, a UNESCO World The ‘emission’ from this process is pure, SYSTRA says it watches all these thing to do for a whole transport solution. Heritage-listed city, the Mayor didn’t drinkable water, making it a non-polluting technology developments very carefully, The ‘net zero’ greenhouse gases by 2050 want people to see unsightly wires. He power source. An additional advantage over which are being increasingly applied to emissions target is a bit of a game changer for was a strong believer that a traditional battery-power is the speed of charging - a few heavy rail systems before their eventual the industry, but at SYSTRA we have been system would meet with stakeholder minutes (roughly the same as a petrol car) in migration to light rail. developing this technology for over a decade.” resistance and that a catenary-free comparison to several hours for a battery. Alstom has already introduced hydrogen He adds: “Battery power is seen as system could be more acceptable, In addition to the onboard equipment, trains onto regional services in , experimental in the UK, but it has been smoothing the way for planning hydrogen refuelling stations are required while in the UK there are partnerships readily available on light rail in China for the permission. He was right - the scheme last five or six years, and we’re starting to see was implemented without objection and much more of it on the heavy rail side. A SYSTRA-led consortium project “Part of the Bordeaux system in the city demand in Bordeaux has exceeded all We are very proud that SYSTRA “The same goes for hydrogen, which is managed the Bordeaux tramway centre uses APS, where electric power predictions. emerging in heavy rail and looks set to make (Communauté Urbaine de Bordeaux) to the tram is supplied by a centre rail “We can say that APS has played has played an instrumental part in its debut in light rail in China. The more you which opened in 2003, and which will that automatically switches on and a key role in unlocking that market, produce, the more the costs come down, so carry more than 430,000 passenger per off when a tram passes over it. This improving the environment and helping making this innovative while there are obvious cost implications for day on completion of Phase 3. prevents any risk of electrocution to reduce congestion whilst maintaining whichever system you go for, these promising System Engineering Manager at pedestrians or other road users. the historical integrity of this proud technology real. technologies will help to solve many of the SYSTRA Mathieu Melenchon explains: “This solution is most appropriate for city.” Mathieu Melenchon, environmental and planning problems we System Engineering Manager, SYSTRA face.” ■

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