SIEMENS

At Siemens Mobility in Vienna, Austria, a huge assembly hall is filled with a maze of half-finished trains and parts for installation in rail vehicles. The components include the mask of a train cab for the Austrian state railway company that consists of a plastic wall sandwiched together with a fiber-insulated panel and aluminum foil. “Having to deal with different materials that are almost impossible to separate is every recycler’s nightmare,” says Dr. Walter Struckl, an expert for environmentally compatible product development. Although Siemens keeps this recycling factor in mind when designing new products, older production series require more work.

Just a few meters farther along in the hall, Struckl shows there is a better way to do things. Here, a frame holds an automated people mover destined for the city of Uijeongbu in South Korea. The train’s aluminum frame is held together by high-strength hexagonal socket head screws that can be easily unfastened, and panels designed to dampen vibrations are simply inserted between the frame and the housing.

Recycling and energy efficiency are the key issues now facing the rail industry. When calling for bids for new subways or trams, customers want suppliers to provide a disposal concept listing all materials used and submit concepts for their reuse. But Siemens is going a step further, providing interested customers with a disposal handbook that explains step by step how a train is disassembled, from draining various fluids, including brake fluid, to shredding plastic parts. Siemens does this because it doesn’t recycle its trains itself, a job handled by specialized companies commissioned by vehicle owners.

A great example of this recycling concept is the Oslo Metro, which is probably the world’s most resource-conserving rail system. Many of the metals in the city’s rail vehicles have already been recycled at least once. Siemens first described the recycling phase in a concept description. The resulting information has since become a part of the customer’s maintenance documentation.

Unlike the automotive industry, which benefits from the ISO 22628 recycling standard, the rail industry didn’t get on the recycling bandwagon until a few years ago. What’s been lacking so far, though, is a guideline that defines a binding method for calculating the recycling rate, and mandatory recycling processes for the entire sector.

This is why Siemens has initiated the creation of a uniform recycling guideline at the Association of the European Rail Industry (UNIFE) in Brussels. The association’s 73 full members, which include Siemens, Bombardier and other major competitors, have a combined market share of 80 percent. These companies want to make technological recommendations later this year that would then serve as the basis for a European guideline as soon as the International Union of Railways (UIC) gives its approval next year. Such a guideline might one day also serve as a possible standard for other means of public transportation such as ships and planes.

Recycling Champion. According to Siemens, the Oslo Metro has a record recycling rate of just under 95 percent. About 85 percent of the materials used are recycled by means of cost-efficient processes; a further ten percent is incinerated. But the recycling rate might be a lot higher when one of today’s trains is scrapped in about 40 years, if higher prices for raw materials make it more worthwhile to reuse resources. The recycling rate would probably also be higher for a comparable rail system in Japan, which has meticulously recycled even individual screws since suffering extreme resource scarcity during World War II.

In principle, the recycling rate can be as high as desired. The crucial thing, however, is for recycling to be cost effective. Recycling rates might even drop at first after the new guideline is introduced because it would no longer leave room for different interpretations of recycling, thus preventing companies from artificially inflating their rates. “The new guideline will give us a competitive edge because our calculations are already realistic,” says Struckl. In fact, almost none of Siemens’ competitors has made as much progress in recycling — no matter what their advertising brochures say.

Even the new guideline won’t be able to predict what will happen over the next 40 years. Some materials now considered nonhazardous could someday be banned, for instance, making them no longer recyclable. An example is asbestos, a health hazard that was once considered perfectly safe and recyclable. The main regulations banning the use of certain materials are the EU’s REACH chemicals directive and the RoHS directive governing use of heavy metals in electronic components.

That’s why it is crucial for product designers to aim for the highest possible recycling rate, even as early as the development stage. Ernst Ille, the team leader for interior fittings at the Vienna plant, explains the possibilities of recycling-compatible design. He points to a block that serves as the pattern for the floor of the new subway trains that will go into service in Munich in 2013. A three-centimeter-thick cork board extends along the entire length of the train (18 meters), to dampen noise from footsteps. Aluminum foil is glued to the top and bottom of the board. On top of the foil is glued a rubber floor sporting blue spots. When the floor is disassembled, the glued-on layers can be pulled off like a skin. Ille’s department and BMW Designworks, a California-based think tank associated with German automaker BMW, jointly came up with the idea of using renewable raw materials like cork.

Creativity Needed. The new Inspiro platform (see article “Build Your Own Train”) contains many ideas for making recycling easy and achieving a recycling rate even higher than that of the Oslo Metro. But the challenge is more formidable if a customer substantially changes a platform. This happened with the city of Munich, for example, which ordered trains containing Inspiro features but assembled according to very specific requirements drawn up by its own designer. “In such situations, to achieve the best results you have to work with the customer to determine the recycling possibilities early on,” explains Ille.

Sometimes designers even face a conflict of interests, since “saving weight is more important than recyclability,” says Ille. That’s because most CO₂ is emitted during operation, and can therefore be best cut if the vehicle’s weight is reduced. For example, the front mask for the cab mentioned at the beginning of this article would be much easier to recycle if it were made of steel instead of the fibrous composite material actually used. But a steel mask would be several kilograms heavier, resulting in higher energy use during operation.

Fortunately, recycling and low CO₂ emissions aren’t mutually exclusive, because a train that is easy to disassemble is usually also easy to put together. An example is the body of the people mover for Uijeongbu. Easy recyclability cuts CO₂ emissions and labor costs during construction and disassembly. And recycling earns the company carbon credits because greenhouse gas emissions are reduced if new raw materials don’t have to be produced or if nonrecyclable materials, including some plastics, are burned to generate energy. The Oslo Metro uses steel containing 40 percent recycled material; aluminum parts consist of 60 percent recycled material. These recycled metals probably aren’t from decommissioned trains, but rather from many different industrial products, which is why most Oslo trains will never wind up in Siemens’ Vienna plant.

Recycling 101. Decommissioned trains are usually recycled by specialized companies. The resulting materials are treated in four different ways:

➔ Reuse: Certain components can be reused for the same purpose without any treatment. For example, the reuse of computer chips in the aerospace industry.

➔ Alternate usage: Similar to reuse, except the component is used for a different purpose, such as using PC microchips in aircraft.

➔ Recycling for similar usage: In this process, the product is broken down to create a granulate that serves as the starting material for a similar product.

➔ Recycling for alternate usage: This, the most common of the four variants, involves breaking down components into their constituent raw materials, which are then used to make simpler products such as park benches or road surfaces.

New York City has come up with a fifth form of recycling. As a popular YouTube video shows, decommissioned subway trains are deposited in the ocean off the Virginia coast, where they serve as artificial reefs that are colonized by corals and fish.