SIEMENS

As more people move into metropolitan areas, the limits of existing transit systems are being tested. Cities around the world are addressing this problem in different ways. China, for example, is investing heavily in a major expansion of its public transportation systems. Such mammoth projects make it possible to manufacture products in large numbers, and they allow standardizations and cost reductions. The situation is different in many European cities, where subway and tram networks are sometimes decades old. Over time, most of these systems have undergone extensions and renovations. The result is patchwork systems that offer few possibilities for optimization or cost-cutting standardizations.

“Every tram system is unique, with its own curves, gradients, tracks, and above all quality,”says Matthias Hofmann, a product manager for trams at Siemens Mobility in Erlangen. Cities that have a long history of tramways, for instance, are more likely to have sharp curvesand obsolete track material. “If a tram isn’t perfectly fitted to the track, enormous forces can be released on some curves — the wear on the track and the vehicle is correspondingly high, and there have even been cases where some passengers have been rattled about in their seats,” adds Hofmann.

Focus on Flexibility. Engineers at Siemens recognized this problem and developed a tram called Avenio. Instead of having a rigid chassis flanked by a long vehicle body, which was the customary approach in the past, this tram features swivel trucks in a central position beneath each module. It’s a simple principle, but one with major consequences because it results in a symmetrical distribution of forces and a big reduction in the stress placed on tramcar joints. That’s why the Avenio can be deployed flexibly — even in older, worn-out track systems. “For instance,” says Hofmann, “in Budapest, with its narrow roads, old sections, and convoluted tracks, we ran a tram for 500,000 kilometers without producing excessive torque on the wheel sets. The wear and tear on the wheels was only one third what it was in designs used by contemporary vehicles in well-maintained Western European tram systems.” A pleasant side effect here is that reduced wear makes for a more comfortable ride for passengers. Trips tend to be quieter and smoother; passengers no longer find themselves pressed roughly to one side, nor do they hear loud screeching and jangling when moving along curves.

The Avenio also features flexible length and width that customers can determine themselves, and uses sophisticated low-floor technology. As the wheel drives are situated at the sides of the bogies and are easily accessible for maintenance, the space between the wheels can be used. In the Avenio, the floor is thus correspondingly low — only a few centimeters above the track bed. Together with its large double doors, this allows completely barrierfree use of the tram by passengers with baby carriages or in wheelchairs, for instance. Other highlights that make the Avenio an all-around user-friendly tram with low lifecycle costs include its electric brake, which operates until the vehicle stops, an advantage not found in previous models; ancillary components that shut off when the vehicle is idle; an intelligent energy management system; and a recycling rate of approximately 90 percent (see "Fast Track to a Second Life").

Subway experts at Siemens Mobility also know a lot about uncertainties related to different transportation infrastructures. In this area, though, differences in track quality are the least significant challenge. “Since the world’s first metro entered service in London in 1863, a panoply of different subway trains has developed, particularly in Western Europe, and all of them differ in height, length, width, and technical equipment,” says Sandra Gott-Karlbauer, head of Siemens’ Metro-Business Unit in Vienna, Austria.

So in the past, any subway system that was ordered had to be tailored to the corresponding track network. Compared to standardized trains, this results in longer development timesand — especially in the case of small production runs — higher costs.

“In order to keep doing business in the subway segment globally, we had to dramatically reduce the cost of individualized vehicles without sacrificing quality,” recalls Gott-Karlbauer. The solution was the Inspiro subway platform, a vehicle based on a building-block approach. “Customers can put together their own personal subways from standardized, prefabricated modules,” explains Werner Chmelar, Inspiro platform manager at Siemens Mobility in Vienna. “That brings a big cost benefit. We can meet customers’ needs with suitable products, but we don’t have to develop them from scatch, thanks to our building-block approach.”

The platform is essentially similar to an auto industry configurator, except that in this case the customer has more options to choose from. For example, the base vehicle of the Inspiro is a six-section unit. Configurations with three to eight sections with different degrees of motorization and features are also possible. “The trains can be put together in accordance with requirements — which means an attractive purchase price for every customer, since customers get only what they need. In that respect, we have bridged the gap between standardization and individualization,” adds Chmelar. And because of economies of scale and lower development costs, risks are smaller, with lower failure rates and reduced maintenance and repair costs for operators.

There are also technical refinements, such as systems for recovering braking energy, and an option for driverless operation. “Inspiro’s development made use of our experience with subways in Oslo and with driverless subways in Nuremberg,” adds Gott-Karlbauer (see Pictures of the Future, Spring 2010, Focus on the Sun, and Spring 2008, Driverless in Nuremberg). Aluminum construction, which makes Inspiro the lightest subway currently available, and a recycling rate of up to 95 percent definitely guarantee the train the title of efficiency champion.

But that alone isn’t enough to get road users out of cars and into trains. Smoothly-running transport connections (see "Flexibility in Motion"), the shortest possible intervals between trains, aesthetic preferences, and, above all, passenger comfort are essential. To that end, Siemens hired product designers from BMW DesignworksUSA to conceptualize the Inspiro’s exterior, as well as its interior furnishings. The result: Large, inviting entrances allow passengers to board the train with ease; LED lights provide varied mood lighting; and broad aisles lend a spacious feel. One design specification that really made the developers sweat was the need for a passenger compartment completely free of electrical cabinets This was achieved by means of several technical tricks. Designers also paid plenty of attention to onboard information and security systems such as displays, cameras, and fire-safety sensors, which make passengers feel safe.

The train is clearly on track for market success. Munich has ordered 21 trains with Inspiro components, and Warsaw — one of Europe’s fastest-growing cities — has commissioned 35 six-section trains as a dress rehearsal for its transportation system of the future.