Analysis of alternative drives for fossil-free track working machinery

To operate the railway safely, the track must be regularly maintained and renewed. This required special construction machinery, most of which today are powered by diesel engines. Particularly large groups of road machines with a length of several hundred meters require up to 1000 liters of diesel oil per kilometer of road laid and renewed.

Track work machines not only make a lot of noise and emissions, but also work around the clock and perform several work steps at the same time, such as renewing the tracks or grinding the tracks. For decades, so-called ballast cleaning machinery has also been used as a standard technology, recycling on average about 50% of the track ballast in situ, thus saving valuable resources and prevent the transportation of materials in the spirit of the circular economy.

Operation and maintenance of track work machinery is resource-intensive, and these specialized vehicles—like everything in the railroad industry—are designed to last.

Matthias Landgraf from the Institute of Transport Economics and Railway Engineering at Graz University of Technology (TU Graz) said: “In terms of sustainability, you can’t just mess with an improved machine and just scrap it. bought 10 or 15 years ago”. ). For this reason, existing facilities must be used as efficiently as possible and in a way that saves resources.

Alternative solutions for different track work machines

Together with the world market leader in rail machinery Plasser & Theurer, the Institute of Railway Engineering and Transport Economics at TU Graz tested all rail machinery and vehicles for the first time. their specific modes of operation and determine the optimal method that does not use fossil fuels. instead of, replace drive technology in each case. In addition, the Institute analyzed the entire fleet of about 3,000 auxiliary vehicles in Germany as part of a research project of the German Research Center for Railway Transport (DZSF) to develop an optimal mobility strategy. switch to alternative energy-powered machines.

Based on the analysis and results of a calculation program developed at TU Graz (CalCAS—comparative computing for alternatives), recommendations were made for alternatives to the machines. Different track working hooks. According to this, a good 35 percent of used machines can include energy requirement “Definitely the most energy-efficient solution” from a technical and legal (labor) point of view over the overhead line, says Landgraf.

For monitoring work machines with energy requirements of up to 800 kilowatt hours (kWh), the researchers propose a battery solution in the form of a combination with an overhead line for charging. In the medium term, there will also be further developments in energy field That could allow pure battery solutions, says Landgraf.

For machines with electricity energy needs more than 800 kWh, a drive using hydrogen fuel cell technology is considered optimal. Existing machinery can bridge the gap by using biofuels or synthetic fuels and, in the medium term, liquid hydrogen combined with internal combustion engines.

Stricter regulations are foreseen

Switching to alternative powertrains will contribute directly to the reduction of greenhouse gas emissions. According to the Institute at TU Graz, rail maintenance work generates 9,600 tons of CO₂ every year in Austria alone.

“It can be assumed that this machine will also be subject to stricter regulations in the future,” says Landgraf. Railway companies are also increasingly aware of the need to reduce their negative environmental impact. Austrian Federal Railways (ÖBB), Prorail in the Netherlands, Deutsche Bahn and other railway companies do not want to buy any new fossil fuel-powered machinery from 2030 at the latest.

The intersection of construction, vehicles and railways

Alternative drive technologies are mainly developed for road vehicles. Matthias Landgraf explains: “Rail machines are also vehicles, but in terms of form they are more like construction machines moving on rails.

Even if the alternative actuators that have been used to some extent in the construction sector are suitable for the machines working on the rails themselves, the infrastructure that powers the machines Building rails powered by alternative energy, such as to charge traction batteries or refuel hydrogen tanks, is needed. in turn closely linked with the railway infrastructure itself.

There are many factors that are very important in the fossil-free future of tracking working machines. According to Matthias Landgraf, the findings of the joint study will support the evaluation of alternative drive technologies for tracking work. machine and weigh the opportunities and risks.

“In the best-case scenario, these results will be incorporated into the regulations and bidding guidelines. This will help keep track of many construction equipment manufacturers in rethinking and retooling, ‘ said Landgraf. ÖBB Infrastruktur AG has taken an important step by purchasing 56 alternative energy maintenance machines from Plasser & Theurer, the first of which will be in service in early 2023.

Equally important is the fact that fossil fuel-free auxiliary vehicles in the rail sector not only contribute significantly to the reduction of the railway industry’s carbon footprint. Electric rail vehicles avoid the emission of nitrogen oxides and particulate matter and are, above all, much quieter—a plus especially for those living along the rail line or work on the machine itself.