SIEMENS has announced plans for a new range of articulated lightweight commuter and regional EMUs, known as Mireo which will replace the current Desiro ML in Europe. Siemens sees the growth in rail passenger numbers in many major European countries, due to increasing road congestion, population growth and increased economic activity, as a driver for the increased sale of electric regional and commuter trains to European operators in the next two decades.
The Mireo platform has been designed as a readily-scalable train available in formations ranging from two to seven cars. Mireo comprises 26m-long driving cars and up to five 19m-long intermediate trailers running on Jacobs articulated bogies each with a 2.65m wheelbase, while the standard outer bogies have a shorter 2.3m-long wheelbase.
“The new articulated design uses many of the components used in the current Desiro City EMU for Britain, which will remain Siemens’ offer for the British market,” Mr Dirk Schwanke, head of platform solutions and strategy, commuter and regional trains with Siemens, told IRJ. “Mireo also uses some components that the Desiro City shares with the latest Desiro ML trains such as those supplied to Belgian National Railways (SNCB) and Austria Federal Railways (ÖBB).”
Siemens’ Desiro EMU with conventional bogies has sold in large numbers in both Britain and Russia since the late 1990s but, apart from the Desiro ML orders from SNCB and ÖBB, has failed to sell in significant quantity in Europe, with Siemens losing out to Stadler’s Flirt, Bombardier’s Talent 2 and Alstom’s Coradia Continental designs, all of which are articulated.
Siemens’ original Desiro Classic train was articulated and most of these were sold as DMUs to German Rail (DB) as the class 642 and exported widely, although articulated EMU versions were sold to operators in Malaysia, Slovenia, Greece and Bulgaria.
Mireo employs what Siemens describes as a modular architecture with a limited range of core components such as traction equipment. These also include a newly-designed, more-energy-efficient transformer, and an inside-frame bogie which was developed for use initially under the class 700 Desiro City trains which are currently entering service with Thameslink in Britain.
Siemens says Mireo could be over 50% more energy efficient than older multiple units due to its lightweight construction, intelligent energy management systems, regenerative braking and driver assistant system. The train is designed for European use and is compliant with the following Technical Specifications for Interoperability (TSI):
- locomotive and passenger
- passengers with reduced mobility
- safety in railway tunnels
- noise, and
- control-command and signalling.
Mireo can be supplied to operate on any European traction current, or as multi-voltage versions able to operate on two or more electrification systems.
Car bodies
The car bodies will be made from lightweight aluminium employing a welded integral monocoque design using large aluminium extrusions where possible to minimise welding. Mireo can be supplied in a variety of configurations ranging from a 52m-long two-car train to 140m-long seven-car set. All equipment is mounted either on the roof or under the floor in pre-determined locations – the exact location for each item of equipment will depend on the specification of the train and where it is to be used as this will determine the traction current voltages to be supported and safety systems to be fitted. Siemens will use roof-mounted dc busbar traction equipment for Mireo.
Schwanke says Siemens has aimed for “minimum internal variance” in the design and configuration of the car bodies, running gear and traction equipment by standardising basic functions while allowing “maximum external variance” in terms of what customers can do with the interior. This will enable Siemens to gain the benefit of “mass customisation” cost reductions while delivering a bespoke interior to meet the needs of each customer. By taking this approach, Siemens says it should be able to reduce the time to market as the basic platform will not alter from one order to another, other than in terms of the train length and performance options.
Siemens says clients can customise the interior in a way that traditional designs do not permit as it will be completely free of other equipment. CCTV, passenger information, Wi-Fi and entertainment systems will be offered as standard although customers do not have to fit all the systems. Schwanke says the Mireo design allows for variable platform entry heights of 550, 760 and 960mm.
Mireo will be capable of 160km/h, although a 140km/h version will be available too. Depending on the planned use, a variety of performance options will be possible ranging from what Siemens calls Eco, with two powered bogies out of five in a four-car train, through to Speedy with four out of five bogies powered giving an acceleration rate of up to 1.2m/s2.
Bogie weight has been reduced by around a third by using both lighter weight bogies and the inboard bearing design developed for the UK Desiro City, while articulation reduces the number of bogies per train. Siemens says it has designed the new train with longer than industry average car bodies to enable a reduction in both the number of cars and bogies per train. For example, a four-car Mireo will be 90m long (with five bogies) compared with a 90m-long Stadler Flirt train which has five cars and six bogies.
Mireo’s external design has been optimised to reduce aerodynamic drag, thereby reducing energy consumption. An onboard energy management system will potentially cut energy consumption by up to 25% compared with existing EMUs. Siemens says that using a driver advisory system could reduce energy consumption by a further 30%.
While Mireo will not be offered as a DMU, bi-mode options are under development which will use batteries for operation to and from non-electrified lines or to bridge the gaps between sections of electrified lines.
Schwanke confirmed that the train is now ready for market and was offered (albeit not branded as Mireo) to Rhine Ruhr Transport Authority (VRR) for its tender for regional and S-Bahn EMUs. However, the contract was won by Stadler in March with its Flirt3XL design. Perhaps Siemens will have more success once its new train is more widely known.
