Alstom’s Citadis is leading the tram market

By May 2006 Alstom’s order book for Citadis trams had recorded almost 800 units, of which 500 have already been supplied to cities around the world. Repeat orders from France, Spain and Ireland have proven the operator’s satisfaction with this modular product. With this overwhelming success, Citadis has made its way to becoming the largest series of low-floor trams ever ordered.

More than 6 years of experience have now been accumulated with customers as varied as Yarra trams in Melbourne, Australia, RET in Rotterdam, The Netherlands and RATP in Paris. A number of improvements and optimisations have been introduced in the product range to increase reliability and availability and thus make this brand even more satisfactory for operators and users and reduce overall operation and maintenance costs. A dedicated team in Citadis’ centre of expertise in La Rochelle on the French Atlantic coast has scrutinised all aspects and worked out solutions. The result is benefiting both operators who already run Citadis trams and those who will get future supplies. One most striking result is that where it was initially thought that wheel life would be limited to about 200,000km, it now reaches 300,000km.

But it is mainly the adaptability of the basic design that has allowed for this success. The decision was made in the mid 90’s to use modules and sub-modules, following a thorough technical evolution process and test programme.

Standards were mainly set up for the interfaces of these modules and for each of them a freedom for adaptation and evolution was given. A number of advantages result from this approach:

• Customers can choose transport capacity, width and power rating of the vehicle to fit their transport needs and infrastructure requirements. Lengths start with 20 metres for about 130 passengers and can go up in 11m steps, adding about 70 passengers for each step. Long trams can be purchased right from the beginning, but it is as well possible to lengthen 30m trams to 40m by introducing additional modules on the operator’s premises if traffic develops. Citadis can be supplied in widths between 2.30 and 2.65m
• Customers can choose the specific aesthetics of their vehicles. As driver’s cabs are completely pre-assembled, a great freedom is given to industrial designers to create a unique image to make their city’s trams an attractive and fashionable means of transport. The same applies to the interior layout, the arrangement and type of seats, stanchions, ticketing and other equipment
• The technological evolution and the introduction of new standards can be easily handled. Energy storage systems can be added, the asynchronous traction motors can be replaced by smaller and lighter permanent magnet motors. With the introduction of the European standard for structural stiffness and crashworthiness, underframe and cab structures could be easily upgraded from 200 to 400kN compression load and an absorbing zone protecting the driver in head-on collisions of up to 20km/h could be easily introduced without affecting the rest of the structure
• Repairs of minor and major accidents are easy. The design is made in a way that accident damage is limited to a very small zone and that damaged parts can be quickly and easily replaced. Broken windows and exterior panels of the drivers cab can be exchanged in a few minutes, complete driver’s cabs have already been replaced and it was shown that it was possible to do it in a few days
• Thanks to the large number of Citadis trams, which share parts in common, spare parts are easily and readily available
• Manufacturing is carried out in a well controlled industrial process, technological changes are only introduced where they bring progress, and thus the risk of starting problems is virtually eradicated.

Alstom’s development objectives go beyond the mere supply of rolling stock. A full range of services, going from maintenance of the vehicles to turnkey supply of a complete system is available, tailored to the specific situation of each application.

In Barcelona, Alstom supplied the complete mechanical and electrical equipment of two tram lines, including the replacement of road signalling with a new system to allow for tram preference. In Barcelona, 37 Citadis are also maintained by Alstom, as are the 22 trams in Orléans, France.

In order to keep historic city centres free from overhead wires, a number of solutions are available, others are under development. At the same time – and with rising energy prices this will become even more important, technologies to reduce overall and peak energy consumption are underway.

To enable trams to run over a few hundred metres of core city centres without catenary, a sophisticated battery system has been developed, combining the latest technology of high-performance NiMH batteries with an energy management logic. This system is being used by the city of Nice, France, where Alstom is currently supplying a series of 20 Citadis. On the total length of the line of 8.5km, two sections of 435 and 485m are catenary-free and energy will come from the battery-system which is being repowered on the rest of the line.

A similar effect can be achieved with a modern high-performance flywheel energy-storage system. A prototype of such a system has been installed on a Citadis in Rotterdam. Tests with this 4kWh equipment have proven that in addition to the possibility to operate without catenary, considerable energy savings can be achieved, the flywheel will store braking energy and will deliver it to the motors when accelerating, thus reducing power-consumption peaks and overall power consumption.

The Innorail APS third rail power supply completely replaces the catenary in cases where long distances shall be operated without overhead wires. Such a system has been built for Bordeaux, France, where 13.7km out of a total network length of 44km is equipped in this way. A third contact rail in the middle between the tram rails coming live with 750V DC by 11m long switchable sections as long as one of the Bordeaux Citadis is over it, feeds the tram. This system has now been operative for two years and maturity has been achieved to the satisfaction of the city.

Some examples of recent supplies and orders of Citadis trams:

• 20 Citadis 30m for Tenerife, Spain. Due to the long and steep gradients of this 12km long line, they are equipped with three motor bogies instead of the usual two motor bogies and one trailer bogie
• 70 Citadis 30m for Madrid, Spain. These vehicles must be able to run on Madrid Metro’s underground network under certain circumstances and are therefore fully equipped for tunnel operation
• 20 Citadis 30m for Montpellier, France. Montpellier already operates a fleet of 40 Citadis partial low-floor trams with 40m length on line 1. The new line 2 will be equipped with 30m long full low-floor Citadis trams
• 24 modules to extend the existing Citadis 301 trams in Dublin, Ireland, to 40m
• 30 Citadis 30m for Tunis. These vehicles will operate in fixed double-traction units, forming a 60m long train, and are therefore equipped with a drivers’ cab on one end only
• 20 Citadis 40m long and 2.65m wide, for the first section of a new tramway line replacing a heavily loaded bus line on the circular ‘Boulevard des Maréchaux’ around the city centre of Paris
• The most recent order is for 18 Citadis 30m for Toulouse, France.