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Research & Development
Technology Press and Innovation Communications

Dr. Ulrich Eberl
Herr Dr. Ulrich Eberl
  • Wittelsbacherplatz 2
  • 80333 Munich
  • Germany
Dr. Ulrich Eberl
Herr Florian Martini
  • Wittelsbacherplatz 2
  • 80333 Munich
  • Germany
pictures video

Siemens' new metros are based on a cost-effective platform concept and a user-friendly interior design.

Strips of colored LEDs mounted in doors fall like sand through an hourglass, indicating that the train is about to leave

Riding in Style

With its trend-setting interior, the new Inspiro metro is a real eye-catcher. But there's more to the concept than just outstanding design. The railcars themselves are carefully tailored to meet the needs of passengers, including those with reduced mobility.

Image Strips of colored LEDs mounted in doors fall like sand through an hourglass, indicating that the train is about to leave.
Image A simulation of passenger flow on a platform and in a railcar helped to determine the optimal door width.
Image Image New box-shaped crash elements fold like an accordion during impact and absorb the impact of a collision, thus preventing the coachwork from buckling. Siemens engineers conducted crash tests to investigate their effectiveness.

The subway train is waiting at the platform. It’s a familiar situation for subway users — having to decide whether to make a dash for it or wait for the next train. At Siemens' Mobility facility in Vienna, Austria the answer is simple. In the door windows, strips of red light that diminish in length, similar to an hourglass, show there is still enough time to board before the strips start to flash and the doors shut. Seconds later, you’re safely aboard, though slightly out of breath. Not that anyone has to hurry to catch the test subway at Siemens Mobility in Vienna. It’s not about to go anywhere and doesn’t even have any wheels, sitting instead on a fixed cradle. Part of the railcar wall has been removed, thus affording potential customers a proper look inside. The view is “revolutionary,” according to engineer Werner Chmelar. He is the platform manager for Inspiro, a light rail train developed in recent years by Siemens here in Vienna. The latest generation is based on a platform concept, which means that most of the components — coachwork, bogie, electrical systems — are always the same. This brings substantial cost benefits compared to predecessor models, which sometimes had to be partly redesigned to meet customer specifications. Chmelar’s job is to ensure that the railcar concept can be matched to market requirements as efficiently as possible.

A closer look reveals what this means. Alongside the mock-up are railcars destined for a new subway in Poland’s capital, Warsaw. These are the first to be based on the Inspiro platform and are scheduled for delivery in April 2013. Hanks of cable still hang out from the roof. It all looks pretty chaotic to the layperson, but in fact the design is amazingly simple. Aluminum sections stretching the full length of the car provide stability and serve as cable ducts and fixtures for LED lamps. Mounted to the edge are vent panels of soft fabric for the air conditioning. Standing nearby are railcars for the Oslo subway system. Their predecessor model caused a sensation a few years back since it was 95 percent recyclable. Here, however, the roof consists of substantially more aluminum sections, which have to be bolted together, and the air conditioning is provided via individually mounted hoses. Similarly, the lights have to be mounted separately. Even the untutored eye can see that this design is much more complicated and costly.

Not that passengers need be aware of the platform concept and all its benefits. What interests them primarily is the look and feel of the interior. In fact, the various elements of the new Inspiro — seats, poles, lighting — all look slightly out of the ordinary, while still seeming absolutely right. "The design is going to cause quite a stir," Chmelar predicts.

He could well be right, as some of the details are truly exceptional. For example, the light strips described above are a completely new feature. They consist of LEDs mounted in the edges of the door windows. When the train enters a station, the light strips shine yellow, so that passengers know from which side of the train to exit. While the doors are open, the light strips shine green. They then change to red and the strips of light start to descend like sand falling through an hourglass. This tells passengers on the platform how much time they have to board the train. When the strips start to flash, it’s time to stand clear of the doors.

The light strips are much more than just a design feature. As Chmelar rightly observes, they offer a genuine benefit for passengers — as do other aspects of the Inspiro concept. "No other subway is quite so passenger-friendly, without having any negative impact on the overall look," he says. Take the design of the grab handles, for instance. Once these would have been loops of leather or rubber; today, all rapid transit trains have grab poles. The new Inspiro takes this idea one step further. Here the poles are in the form of stylized trees with branches that fork upwards. They are the fruit of a brainstorming session that was aimed at creating a symbol of sustainability that also has a practical function. The branches are set at various heights, thus providing handholds for people of different heights. All in all, there is room for dozens of hands.

New Metro in Crash Test. In the unlikely event of a collision, passengers are protected by new box-shaped crash elements mounted under the driver’s cabs. These crumple during impact and can absorb the force generated at crash speeds of up to 25 kilometers per hour without any buckling of the coachwork. In the past these crash elements were not installed unless they were expressly requested by the customer. However, without them railcar bodies would tend to buckle at a crash speed of 15 kilometers per hour. To study the performance of these elements, a number of crash tests were conducted. A high-speed camera showed how the corrugated ends of the absorbers mesh and thereby prevent the front of the train from rearing up.

Intelligent design has also been applied to the lighting concept, which utilizes low-energy LEDs that change color. In the morning they shine bright blue, which helps people wake up; in the evening they change to a more subdued, warmer light, which has a soothing effect. Such a concept exploits the findings of lighting experts from Osram, who have demonstrated that specific colors of light can influence users’ moods — and save energy. Indeed, the color of light even has an influence on the sensation of temperature. Blue light, for example, suggests cold, and red light warmth. Incredibly, blue light on a hot summer day reduces the demand for air conditioning, and red light in winter helps cut heating costs. Indeed, studies indicate that the color of light can influence the sensation of temperature by as much as two degrees Celsius, which corresponds to an energy saving of five percent.

Klaus-Peter Wegge from Siemens Corporate Technology in Paderborn has expertise in another vital area. Being visually impaired, he’s very much in demand as a specialist regarding accessibility, i.e. ensuring that a product, service, installation or environment is available to as many people as possible, including people with disabilities or special needs. Wegge and his team have been advising Siemens engineers in this field for a number of years now. In the spring of 2012 he and his colleague Markus Dubielzig were in Vienna to give the Inspiro mock-up a thorough going-over during a period of two days. They examined and documented all the passenger-relevant railcar components with respect to their accessibility to people with various disabilities. Wegge was very impressed with the concept of the light strips on the doors, even though he couldn’t see it in action and an acoustic counterpart is still lacking. He also commended the fact that there is plenty of room for guide dogs under the seats.

One area of criticism was the lack of grab poles right next to the doors. In railcars with longitudinal seating the poles are set back by 60 centimeters from the doors, and in those with lateral seating they are set back by 90 centimeters. "Our designers are now looking at ways to improve this feature," Wegge explains. The Paderborn team also praised the wide doors, which at a span of 1.40 meters, provide ample room for wheelchairs, visually impaired passengers accompanied by a sighted guide, and people using walkers. But are they also wide enough to allow faster boarding and exiting?

In order to find out, designers at Siemens Mobility in Vienna commissioned a computer simulation. The German Aerospace Center (DLR) in Braunschweig has extensive experience in the use of mathematical models to calculate flows of people. Such data is vital in planning for the evacuation of large buildings and sports arenas.

The DLR model simulated the speed at which passengers typically board and exit from subway cars and how they move inside the train when looking for a seat.

The simulation clearly showed that doors 1.40 meters wide were perfectly adequate and that doors 1.60 meters in width would result in a time saving of only a fraction of a second. Narrower doors were not investigated, but experience shows that they increase passenger crush and therefore platform times for trains.

In this respect, seating configuration is a more significant factor than door width. Lateral seating, the traditional configuration, impedes the flow of passengers and extends passenger changeover times by quite a few seconds. In other words, there is good reason behind the growing trend on the part of light rail operators to request a longitudinal configuration with the seats mounted along the railcar walls.

The mock-up in Vienna is unlikely to provide the template for any order from a real customer. Featuring stylish light-brown leather seats and bronze-colored grab poles, it was specially designed for a trade show in Dubai. The trains that will be rolling in Munich’s subway network as of 2013, on the other hand, will feature Inspiro components and their very own styling based on the corporate design of the city’s urban transport operator, Münchener Verkehrsbetriebe. Pictures hanging in Werner Chmelar’s office show what awaits passengers in Munich: a blue-and-white color scheme for the interior, with large doors and wide passageways to make travel faster and more comfortable.

Bernd Müller