Deutsche Bahn AG Research Articles

Predicting the risk of tree fall onto railway lines

Tree fall onto railway lines puts passengers at risk and causes large economic losses due to disruption of train services and damage to infrastructure. Railway lines in Germany are vulnerable to tree fall because of the large number of trackside trees that exist in that country with approximately 70% of all railway lines being tree-lined. In this paper we first tested whether a hybrid-mechanistic tree wind damage model, ForestGALES, could identify the sections of the railway network affected by tree fall in two federal states of Germany, Northrhine-Westphalia (NRW) and Thuringia (TH). We secondly tested whether the model, in combination with meteorological forecast models, could predict where tree fall occurred during a damaging windstorm. We used information on tree characteristics derived from LiDAR and aerial photography along the railway line network in NRW and TH to calculate the critical wind speed (CWS) at which damage is expected to happen for every individual tree as a function of its size and species, and the underlying soil. The railway network was then divided into 500 m sections and the statistics of the CWS, tree height, and species composition (broadleaf/conifer mix) within each section were calculated. Analysis of past tree fall events recorded by Deutsche Bahn AG (DB) showed that there was a significantly lower minimum CWS and significantly greater maximum tree height in sections that had recorded damage. In a second step we compared the calculated CWS values for all trees against downscaled wind speed assessments across the two federal states during Storm Friederike (named Storm David internationally) on 18 January 2018 and tested the ability of the model to discriminate sections with recorded damage during the storm. Excellent model discrimination was found with an AUC value of 0.82 and an overall model accuracy of 74.2%. The first test showed that the ForestGALES model with precise individual tree information can identify the sections of a railway network most vulnerable to tree fall. The second analysis showed, for the one storm tested, that the ForestGALES model when combined with predicted storm wind speeds can identify the most probable sections of the railway network to experience tree fall during an approaching damaging storm. Such information could be of value in firstly planning remedial work along railway lines, and secondly preparing the railway network ahead of a major storm.

EETTlib—Energy‐efficient train timetabling library

AbstractWe introduce EETTlib, an instance library for the Energy‐Efficient Train Timetabling problem. The task in this problem is to adjust a given timetable draft such that the energy consumption of the resulting railway traffic is minimized. To this end, the departure times of the trains can be slightly, and their velocity profiles on each trip can be modified. We provide real‐world data originating from two research projects in this field, one with Deutsche Bahn AG, the most important railway company in Germany, the other with VAG Verkehrs‐Aktiengesellschaft, the operator of public transport in the city of Nürnberg, Germany. In both cases, our library contains representative data on the relevant operational constraints and supports various possible choices for the objective function with respect to energy‐efficiency. The resulting benchmark instances can be used by the scheduling and timetabling community to improve their models and algorithms. They are available under https://www.eettlib.fau.de.

Towards a climate neutral future with Deutsche Bahn: Analysis of company policy until 2050

The purpose of this paper is to analyze the state of current knowledge and tools needed to move the German company Deutsche Bahn AG towards climate neutrality. Both literary sources and statistical data were used in the preparation of the paper. The main questions addressed in the paper are: how the concept of climate neutrality applies to Deutsche Bahn AG, what experience the company has in planning carbon-neutral operation and what tools can be used. As greenhouse gas emissions rise, so does the need to find solutions for reducing carbon dioxide emissions. Deutsche Bahn AG is aiming for climate neutrality by 2050. To achieve this goal, it is primarily relying on the use of renewable energy to power overhead cables and train stations. In addition, alternative engine options are being developed to replace the existing fleet of diesel locomotives on non-electrified sections. Improving the energy efficiency of both rolling stock and railroad stations is also becoming increasingly important.

Fiber Optic Train Monitoring with Distributed Acoustic Sensing: Conventional and Neural Network Data Analysis.

Distributed acoustic sensing (DAS) over tens of kilometers of fiber optic cables is well-suited for monitoring extended railway infrastructures. As DAS produces large, noisy datasets, it is important to optimize algorithms for precise tracking of train position, speed, and the number of train cars. The purpose of this study is to compare different data analysis strategies and the resulting parameter uncertainties. We present data of an ICE 4 train of the Deutsche Bahn AG, which was recorded with a commercial DAS system. We localize the train signal in the data either along the temporal or spatial direction, and a similar velocity standard deviation of less than 5 km/h for a train moving at 160 km/h is found for both analysis methods. The data can be further enhanced by peak finding as well as faster and more flexible neural network algorithms. Then, individual noise peaks due to bogie clusters become visible and individual train cars can be counted. From the time between bogie signals, the velocity can also be determined with a lower standard deviation of 0.8 km/h. The analysis methods presented here will help to establish routines for near real-time train tracking and train integrity analysis.

Testing the effectiveness of an inverse Wenner-Schlumberger array for geoelectrical karst void reconnaissance, on the Swabian Alb high plain, new line Wendlingen–Ulm, southwestern Germany

On the Swabian Alb high plain, southwestern Germany, the new high-speed railway line Wendlingen–Ulm of the German Railway Company (Deutsche Bahn AG) is currently under construction. 2.5D electrical resistivity tomography (ERT) measurements (meaning the use of parallel 2D lines) were performed at the excavation bottom level in addition to the investigation program of the construction company including microgravimetric and seismic methods. The aim was to test the effectiveness of an inverse Wenner-Schlumberger array for exploring geological defective karst voids and other karstic features in a highly heterogeneous karstic environment. A complete 3D ERT survey (meaning the use of additional orthogonal cross-lines) was not carried out due to restrictive circumstances (terrain effect, anisotropic effect). The 2.5D ERT survey (ABEM Terrameter SAS 4000, inverse Wenner-Schlumberger array, six lines, 60 m line length, 0.75 m electrode spacing, lines oriented perpendicular to the long axis of an oval-shaped collapse doline and the most prominent voids, 1.5 m line spacing, smoothness-constrained least-squares/robust inversion, RMS error: 1.60–3.20% for a maximum of 5 iterations) provided resistivity values of marls and marlstones, a limestone bedrock, a collapse doline and of an air-filled cavity. A clear demarcation between the marls and marlstones and the limestone bedrock was only possible outside the area of influence of the collapse doline; the latter could not be exactly delineated from the adjoining geological units. In addition, one of three air-filled voids (open fractures, cavities) could be derived accurately in location and roughly in size and shape from the 2.5D ERT survey; the other two were not detected by means of ERT because of (i) its location beneath a high-resistive anomaly and (ii) its comparatively small maximum horizontal opening width of only 1 time the used inter-electrode spacing. Extensive direct probing investigations served for calibration and discussion. The 2.5D ERT measurements conducted with an inverse Wenner-Schlumberger array complemented the microgravimetric and seismic results of the previously conducted investigation program of the construction company and provided a contribution to karst void reconnaissance in a highly heterogeneous karstic environment like the Swabian Alb high plain, on the new line Wendlingen–Ulm.

Formal modeling and analysis of railway operations with active objects

We present a comprehensive model of railway operations written in the active object language ABS. The model is based on specifications taken from the rulebooks of Deutsche Bahn AG. It is statically analyzable and executable, hence allows to use static and dynamic analysis within one and the same formalism. We are able to combine aspects of micro- and macroscopic modeling and provide a way to inspect changes in the rulebooks. We illustrate the static analysis capability by a safety analysis based on invariant reasoning that only relies on assumptions about the underlying railway infrastructure instead of explicitly exploring the state space. A concrete infrastructure layout and train schedule can be used as input to the model to examine dynamic properties such as delays. We illustrate the capability for dynamic analysis by demonstrating the effect that different ways of dealing with faulty signals have on delays and propagation of delays. • Formal verification of railway on the operational level with active objects. • Safety analysis on arbitrary, unbounded networks with deductive verification. • Analysis of capacity and propagation of delays with simulation. • Uniform approach to modeling: Global effects of local changes can be analyzed.

PROJECT SCOPE MODELLING OF ARCHITECTURAL AND SPATIAL ACCESSIBILITY OF RAILWAY STATIONS

Current approaches in the organization of the architectural and spatial accessibility of civil engineering objects are analyzed. The focus of the research is state building codes required for the development of architectural design and technical solutions of the railway station complex. It is noted that passengers with reduced mobility include not only disabled people but also older people, pregnant women, parents with children, people with temporary injuries, etc. Inclusive components in the functioning of the railway companies «Ukrzaliznytsya» (Ukraine) and Deutsche Bahn AG (Germany) are compared. The matrix for tracking the requirements of low-mobility groups of passengers in the projects of the organization of the architectural and spatial accessibility of the railway station complex has been developed. The seven groups of requirements to the design of the organization of the railway station availability are formed: barrier-free movement on the station and the adjacent territory; parking area; inputs and outputs, doors; stairs and ramps; corridors, transitions to railway platforms; bathrooms; railway ticket offices, luggage storage, payphones, ATMs. The mathematical description of models of the estimate of architectural and spatial accessibility of the railway station complexes for passengers with limited mobility is offered. It is noted that the estimate of the inclusiveness of design solutions of the railway station complex by passengers with limited mobility groups can be integrated into the procedure for selection of projects for the formation of the programs and portfolios projects content, oriented to the architectural and spatial accessibility of Ukrainian railway stations. Audit of architectural and spatial accessibility of the railway station complex «Kharkiv-Passazhirsky» is carried out. According to its results, «weak spots» in accessibility from the point of view of the needs of all different low-mobility groups of passengers were identified.

A Decomposition Method for Multiperiod Railway Network Expansion—With a Case Study for Germany

In this work, we report about the results of a joint research project between Friedrich–Alexander–Universität Erlangen–Nürnberg and Deutsche Bahn AG on the optimal expansion of the German railway network until 2030. The need to increase the throughput of the network is given by company-internal demand forecasts that indicate an increase in rail freight traffic of about 50% over the next two decades. Our focus is to compute an optimal investment strategy into line capacities given an available annual budget, i.e., we are to choose the most profitable lines to upgrade with respect to the demand scenario under consideration and to provide a schedule according to which the chosen measures are implemented. This leads to a multiperiod network design problem—a class of problems that has received increasing interest over the past decade. We develop a mixed-integer programming formulation to model the situation and solve it via a novel decomposition approach that we call multiple-knapsack decomposition. The method can both be used as a quick heuristic and allows for the extension to an exact algorithm for the problem. We demonstrate its potential by solving a real-world problem instance provided by Deutsche Bahn AG and use the results as the basis for a broad case study for the expansion of the German railway network until 2030.

Arrive in Time by Train with High Probability

Very often, a train passenger must meet a deadline at the destination, for example, to catch a plane or to arrive at an important meeting on time. Train delays and broken connections let the passenger arrive later than scheduled. Events of this kind are usually not foreseeable before the journey commences. To be on the safe side, a connection should be prebooked such that, in case the connection breaks anywhere, alternative continuations guarantee arrival prior to the deadline with acceptably high probability. For busy people, the challenge is to commence the journey as late as possible, provided the risk of failing to meet the deadline is negligible. This scenario translates into the problem to find the latest connection plus alternative continuations such that the probability of meeting the deadline is not lower than a given required probability of success (close to 100%). We present a dynamic-programming approach to this optimization problem and report on an empirical study based on comprehensive real-world data from Deutsche Bahn AG, the German national railways company. Our algorithm efficiently computes optimal results.

A comparison of performance metrics for balancing the power consumption of trains in a railway network by slight timetable adaptation

We investigate the problem of designing energy-efficient timetables for railway traffic. More precisely, we slightly adapt a given timetable draft before it is published by moderately shifting the departure times of the trains at the stations. To this end, we propose a mixed-integer programming model for feasible adaptations of the timetable draft and investigate its behaviour under different objective functions which fall into two classes: reducing the energy cost and increasing the stability of the power supply system. These tests are performed on real-world problem instances from our industry partner Deutsche Bahn AG. They show a significant potential for improvements in the existing railway timetables.

The technical solution for working beneath the protected DB directorate building on the major Stuttgart 21 project

AbstractBuilt in 1914, the listed Reichsbahn directorate building was formerly used as an administrative building by Deutsche Bahn AG in Stuttgart. The Stuttgart 21 Project requires new tracks from the Feuerbach and Bad Cannstatt Tunnels to be built, which branch off from 4 to 8 tracks in the area beneath the DB directorate. Complete demolition of the directorate building was not possible due to the objection of the listed monument authorities, the city administration, the municipal council of architects and the former building owner Vivico. In view of this the preservation of the main building was specified in the planning decision of 28/01/2005.In order for the new station to be constructed by cut‐and‐cover, part of the building had to be secured and underpinned. The design should also take into account two single‐track underground rail tunnels beneath the building and newly constructed temporary retaining structures. The temporary works required to distribute the building loads extended over an area of 800 m2, around half of the building footprint, and poses particular constraints on the design and construction approach due to the building preservation order and its inner city proximity.

Deutsche Bahn AG: a former monopoly off track?

Synopsis Deutsche Bahn AG (Deutsche Bahn hereafter) was the former German railroad monopolist until deregulation in 1996. It was a well-known company that operated in worldwide markets for transport and logistics at the time of the case (late 2013). The case “Deutsche Bahn AG: a former monopoly off track?” focuses on the opportunities and challenges faced by Deutsche Bahn with regard to its position in the German individual transportation market. On the one hand, Deutsche Bahn is facing external problems. Increasing competition in short- and long-distance traffic threatens its strong business position. The competition emerged from a growing long-distance bus market and the increase in private railway companies. During the last few years before 2013, Deutsche Bahn has lost several public tenders for individual passenger travel in Germany. On the other hand, Deutsche Bahn has internal problems that endanger its image as a service company. A lack of service quality and the technical condition of its trains has led to rising numbers of customer complaints. In addition, staffing and punctuality problems have exacerbated the situation. One of the main technical issues the company faces is that ordered trains have not been delivered on time. Given the focus on Deutsche Bahn’s domestic challenges, its international business activities are tackled only briefly. While regulatory and political events have an impact on Deutsche Bahn, these are not the main subjects of the case. Research methodology This case has been written from public sources. Consequently, no company release is provided. None of the information has been disguised in any way. Relevant courses and levels The case is intended for use in a 90-minute strategic management class attended by students at the end of their undergraduate studies or in postgraduate study. Although the case relates to issues in strategic management, the special regulatory environment and some of the issues covered could make the case a useful complement in other classes as well, such as classes in supply chain management (procurement) or the management of public companies. Therefore, students should have basic knowledge in developing strategies, management, marketing, human resource management, and finance. Theoretical bases Strategic Analysis and Strategic Management, Railroad Logistics, Deregulation of a former Monopoly, Stakeholder Theory.

Intercity bus deregulation in Germany – Intramodal and intermodal effects after two years

At the THREDBO 12 Durban Conference in 2011, in a paper entitled “The Case for Intercity Bus Deregulation in Germany” (Knorr, Eisenkopf, Arndt and Burgdorf, 2011), we presented our ex ante assessment of the potential effects of intercity bus deregulation in Germany. This deregulation finally took effect January 1st, 2013. Our analysis led us to expect that substantial economic benefits were likely to accrue to the travelling public and society as a whole. In particular, we assumed that (potential) passengers – especially those from lower income brackets – would stand to gain massively from lower prices and a larger variety of travel options due to overlapping competing networks, at least on trunk routes (of which substantially more exist in Germany than in the UK, the USA or Sweden, given the country's polycentric economic geography, its high population density and very even spatial distribution of the population). Further, we expected that these economic benefits would not be limited to intercity bus travellers, as we also held that the imminent liberalization should force Deutsche Bahn AG to lower prices for their rail services and to improve the quality of its competing offerings. Last but not least, we stressed the crucial role of competition policy for these economic benefits to fully materialize. Our main concern then was that incumbent Deutsche Bahn AG might attempt to abuse the massive pre-liberalization dominance it had held on the regulated intercity bus market, in combination with its nearly intact de facto monopoly on long-distance railroad services, to stifle the genesis of this new market in its early stages with the aim to undermine the rise of potent intra- and intermodal competitors. In this paper for THREDBO 14, we contrast our 2011 projections with the observable intra- and intermodal effects in the two years since the German intercity bus market has been liberalized. In addition, we provide an overview of the corporate strategies of the new intercity bus operators and the strategic adjustments implemented by Deutsche Bahn AG.

The Freight Train Routing Problem for Congested Railway Networks with Mixed Traffic

We consider the following freight train routing problem (FTRP). Given is a transportation network with fixed routes for passenger trains and a set of freight trains (requests), each defined by an origin and destination station pair. The objective is to calculate a feasible route for each freight train such that the sum of all expected delays and all running times is minimal. Previous research concentrated on microscopic train routings for junctions or inside major stations. Only recently approaches were developed to tackle larger corridors or even networks. We investigate the routing problem from a strategic perspective, calculating the routes in a macroscopic transportation network of Deutsche Bahn AG. In this context, macroscopic refers to an aggregation of complex and large real-world structures into fewer network elements. Moreover, the departure and arrival times of freight trains are approximated. The problem has a strategic character since it asks only for a coarse routing through the network without the precise timings. We provide a mixed-integer nonlinear programming (MINLP) formulation for the FTRP, which is a multicommodity flow model on a time-expanded graph with additional routing constraints. The model’s nonlinearities originate from an algebraic approximation of the delays of the trains on the arcs of the network by capacity restraint functions. The MINLP is reduced to a mixed-integer linear model (MILP) by piecewise linear approximation. The latter is solved by a state-of-the art MILP solver for various real-world test instances.

Fatigue cracks in railway bridge hangers due to wind induced vibrations – Failure analysis, measures and remaining service life estimation

Unexpected wind-induced vibrations of the hangers have caused an early fatigue crack on specific steel components and joints of a railway bridge over the Elbe River at Lutherstadt Wittenberg, Germany. During regular periodic inspection a fatigue crack of approximately 240mm length was found near a butt weld of the longest hanger. The hanger was immediately secured by welded butt straps across the crack. Based on experimental investigations of hanger vibrations additional bracings were added between the hangers to avoid wind-induced vibrations. The weld heat influence zone which was affected by high cyclic stresses was replaced by new material.Nevertheless it was impossible to determine sufficient remaining service life for those remaining bridge components that were exposed to extreme high real load cycles. The grinding of the affected steel surfaces was the key element of the remedial actions. Furthermore, additional fracture mechanic calculations were carried out in order to assess the remaining service life of the welded joints. In this respect, the calculation approach used by Deutsche Bahn AG was compared to further procedures from the mechanical engineering field. These investigations showed that the studied, repaired components have both, bearing and fatigue capacities within the validity of standards.

Heuristics for solving a capacitated multiple allocation hub location problem with application in German wagonload traffic

Abstract In this paper, we present a capacitated multiple allocation hub location problem, which arose from a network design problem in German wagonload traffic. We develop heuristic solution approaches based on local improvements. We solve the problem with the heuristics and CPLEX on test data sets provided by our partner Deutsche Bahn AG. The computational results are presented and compared.

Zugangsentgelte zur Infrastruktur der Deutsche Bahn AG: Fluch oder Segen durch vertikale Separierung?

Abstract It has been a policy proposal since long to vertically separate transport and infrastructure in Germany’s railway sector. The proposal received new momentum, when selling the transport subsidiaries of Deutsche Bahn AG to the public was discussed in 2008 / 2009. While vertical separation is general ly understood to prevent foreclosure and discrimination by the incumbent network- operator, advocates of vertical integration claim separation to have adverse effects on access prices to the infrastructure. We examine the price setting incentives of an integrated and a separated network-operator and compare our results to rough empirical findings on the profitability of the Deutsche Bahn AG infrastructure branches. Theoretical analysis highlights that after separation exceptional mark-ups on access prices to the railwayinfrastructure are feasible only in segments of railway-transport with insufficient competition. We therefore conclude that an economic policy for the railway sector directed on efficient supply and promoting effective competition should unbind itself from alleged price synergies and should press ahead with vertical separation instead.

Technologies for exhaust aftertreatment testing under real conditions

The use of exhaust aftertreatment technology in off-highway applications is not yet universally established. For this reason, MTU Friedrichshafen GmbH and Deutsche Bahn AG conducted a joint research project involving early testing of various basic technologies for exhaust gas aftertreatment (EGA) under real conditions. The knowledge gained in the rail applications sector will be transferrable to other sectors and it will also be possible to combine the basic technologies involved in different ways.

Cyclic deformation behaviour of railway wheel steels in the very high cycle fatigue (VHCF) regime

In the present contribution, the cyclic deformation behaviour of the railway wheel steels SAE 1050 and SAE 1060 was investigated in the very high cycle fatigue (VHCF) regime using a resonance testing device at a frequency of 200 Hz. The specimens were machined from the area of the ‘limiting-diameter’ of original monobloc-wheels. The wheels were provided by a system supplier of the Deutsche Bahn AG. The cyclic deformation behaviour is analysed by using highly precise methods for measuring the frequency, temperature and electrical resistance, which show deformation-induced changes of the microstructure within the bulk material during the fatigue process. The initial state of the material is investigated thoroughly by using light-, scanning- and transmission electron microscopy. The dislocation structure was investigated in defined fatigue states showing dislocation walls at 5% N f and dislocation cells at 85% N f . S– N (Woehler) curves are presented for both wheel steels. Fatigue failures at N f > 10 7 were observed.

A Balanced Scorecard for Managing the Aging Workforce

In most industrialized countries, organizational science and practical management have fully accepted the challenge of dealing with the aging of the available labor pool. The demographic data on companies’ workforces have made it clear that the average age within their organizations is continuously increasing. Simultaneously, they find it more difficult to attract capable and younger replacements, whether for blue or white collar positions across all industries. The average age is not, as such, a cause for company concern. The related challenges and problems that could arise in the long term do, however, need to be taken seriously. Empirical studies have proven that, first, there is a tendency towards a growing number of constrained workers and employees who are less flexible in terms of their employment if a company’s personnel are of a higher average age. Second, such aworkforce’s number of sick days (but not the number of illnesses) increases due to their requiring a longer convalescent period. Third, employees who retire could be taking important knowledge with them— especially if the timely transfer of knowledge to the next generation (if available) has been ignored. The detailed issues and challenges arising from an agingworkforce are very specific, depending largely on the business environment, the industry, and the organizational culture. However, these issues and challenges’ potential effects on organizations’ overall strategic performance, especially in terms of cost structure and, thus, financial performance, are obvious. An organization that has to bemanagedwhile many of its employees are on extended sick leave or finds that important key employees have taken their unique know-howwith themwhen retiringwill struggle in a competitive business environment. Facing and acknowledging the above problems, eight global corporations headquartered in Germany and Switzerland (Daimler AG, Deutsche Bahn AG, Deutsche Bank AG, EnBW AG, Lonza Inc., Mars Inc., Otto Group, and Volkswagen AG) formed a joint network. This network is aimed at addressing and mastering the mutual challenges arising from the aging workforce and developing appropriate strategic tools with which these organizations can maintain their performance. All the participating companies recognize that there is an ongoing and active debate with regard to their demographic situation. Moreover, they realize that a systematic and concerted effort should be made to develop strategies as a tool to protect their demographic fitness and to improve their competitive and innovative abilities on the long term. In the words of Martina Klug of EnBW AG: ‘‘Participating in the network enabled us to deduce pragmatic approaches based on science and to share experiences with other companies that also have to deal with this issue.’’ Michael Adolf Picard, personnel director at the Otto Group, agrees: ‘‘In our opinion, it is critical that the demographic change is taken seriously and that we act at an early stage. On the other hand, it is important to avoid wild actionism (acting for the sake of acting) and panic. In my opinion, the recent demographic development is not a revolution but an evolution, which allows a targeted reaction.’’ Carla Berg, Mars University’s talent manager, states: ‘‘The better we prepare ourselves at an early stage, themore successful we will be in the future.’’ It is therefore clear that a model is required with which an aging workforce’s performance in respect of organizational competitiveness and innovativeness can bemeasured,monitoredandadjustedbypayingspecific attentiontoproductivityandcreativitymeasures.Based on the insights gained from the data collected in the relevant companies’ numerous moderated joint sessions, this article will introduce such a model. However, we start off by first introducing our data collection approach via a needs assessment and analysis of the participating companies; thereafter, we discuss the five organizational action fields that are relevant to the issue, and ultimately introduce a balanced scorecard for managing the aging workforce.