SIEMENS

The assembly hall is filled with locomotives, some of them missing their roofs, others without control cabins. And some are even mounted on temporary platforms that make them appear to be floating on air. Martin Leitel, who is responsible for making life cycle assessments of locomotives for Siemens Mobility in Allach, Germany, points to a yellow locomotive without a roof. "That one's going to Australia," he says, a country where rail service operators recently started making energy conservation a higher priority. In fact, the model will be the first electric locomotive on the island continent to be equipped with an energy recovery system. The system collects braking energy generated on downhill stretches by trains full of coal that are traveling from the interior of the country to the coast. It then feeds the energy into the grid for use by empty trains going uphill.

Another locomotive, Leitel explains, is for a European leasing company. It's equipped with a transformer that achieves optimal efficiency because it was built using more copper than is usual, which also makes it heavier than similar units. In order to compensate for the transformer's additional weight, other parts of the locomotive must be lighter, which is why its roof is made of aluminum. Naturally, all of this results in higher energy consumption during manufacturing. But, as Leitel points out, after only a few years of operation, the transformer's high efficiency and the aluminum's light weight counterbalance these energy costs.

Such conflicts are a part of Leitel's routine. In addition to conducting life cycle assessments (LCAs), his job at the Allach locomotive factory near Munich is to ensure coordination with customers when drawing up custom-tailored technical specifications for their locomotives. Combining these two goals has proved to be a good idea. "Customers simply want a good locomotive that meets the highest environmental standards," he says. What's more, life cycle analyses are often a prerequisite for taking part in tendering processes.

Quick LCAs. Munich has been a locomotive production site since 1841 — at one time under the name Krauss-Maffei, whose logo still adorns the front of the factory hall that Siemens took over in 1999. But much has changed over the years. While steam locomotives churned out enormous amounts of soot and carbon dioxide, their modern counterparts are subject to strict environmental regulations. And it's not just the emissions caused by operation of these powerful locomotives that need to be low; environmental impact throughout their entire life cycles must also be kept to a minimum. This begins with the manufacturing process and continues all the way through the product's life to disposal, which will soon become the legal responsibility of the manufacturer. As a result, developers must now plan to recycle as many components as possible.

To ensure that the associated analyses — also known as material balances — remain accurate, Leitel relies on an extensive database containing thousands of parts numbers and information on the materials used in each component. This database reveals, for example, that the left door of a locomotive control cabin weighs 87.1 kilograms, including 68.1 kg of aluminum, 6.6 kg of glass, and 4.2 kg of elastomers, with the remaining weight accounted for by other materials, including steel and insulation elements.

Just a few mouse clicks is all it takes to evaluate specific assemblies or material classes and determine their proportion of total weight. Another database lists the primary energy consumption and carbon dioxide emissions associated with each material, as well as regional differences. For example, an aluminum panel made in Iceland, a country that uses a lot of renewable energy, has a much lower CO₂ value than one from China, where most electricity is generated in coal-fired power plants.

The material analysis does not extend down to the last bolt; this would require too much effort and expense. "We make a general estimate of the energy consumption and emissions of small components," Leitel explains. The analysis ultimately produces charts that show where energy consumption is highest. With freight trains it's clearly locomotive operation itself. Over a service life of roughly 30 years, a locomotive in Europe emits between 200,000 and 400,000 t of CO₂, depending on the type of use. Locomotive production results in only about 250 t of CO₂ emissions, however. And the recycling phase generates savings of 100 t of CO₂ because over 95 % of the materials in a modern locomotive are recyclable. These materials — for the most part metals and coolants — are reused, which obviates the CO₂ emissions that would have been produced if the materials had been manufactured from scratch.

Materials Review. Leitel believes that the material analysis process can be improved. "We're reviewing the entire range of materials now in use," he says. The idea is to use batteries that don't contain heavy metals, as well as coolants made of biodegradable materials — and to generally ensure that new designs have more recyclable parts by avoiding use of composites as much as possible. "The ideal would be to loosen a few bolts and have the whole locomotive break apart into sets of unmixed materials," Leitel explains.

Not every trend is as good as it sounds, however. Although lightweight construction with plastics and composites reduces operating energy consumption, it also poses recycling problems, which means that it is not necessarily good for the environment. A locomotive also shouldn't be too light because it has to pull a train 20 to 30 times its own weight. When asked if all the environmental effort that is now being implemented will ultimately pay off in the form of orders, Leitel says he's certain it will, but cautions that "the locomotive market is price-sensitive, so the sales price is still often decisive."