Know-how, smart strategies and dedicated equipment

Posted: 8 April 2008 | | No comments yet

In order to be competitive on the liberalised rail transport market, the ÖBB Group must operate with market-oriented companies. A key success factor is the reliable transport handling and, thus, the reliability of the infrastructure facilities. That is where the division Infra Service of ÖBB-Infrastruktur Betrieb AG comes in.

In order to be competitive on the liberalised rail transport market, the ÖBB Group must operate with market-oriented companies. A key success factor is the reliable transport handling and, thus, the reliability of the infrastructure facilities. That is where the division Infra Service of ÖBB-Infrastruktur Betrieb AG comes in.

In order to be competitive on the liberalised rail transport market, the ÖBB Group must operate with market-oriented companies. A key success factor is the reliable transport handling and, thus, the reliability of the infrastructure facilities. That is where the division Infra Service of ÖBB-Infrastruktur Betrieb AG comes in.

ÖBB-Infrastruktur Betrieb AG was founded in 2004 together with Rail Cargo Austria, ÖBB-Personenverkehr and ÖBB-Infrastruktur Bau as one of four public companies and five limited liability companies. These companies have been in operation since 1 January 2005. Dipl.-Ing. Herwig Wiltberger and Mag. Arnold Schiefer are in charge of this part of the ÖBB Group with a staff of just under 12,000. Apart from operational planning and shunting, ÖBB-Infrastruktur Betrieb AG is responsible for the provision, operation and maintenance of a safe railway infrastructure in line with demand. This specifically means:

  • Non-discriminatory allocation of train paths
  • Approval of rail vehicles
  • Assistance in the application for operation licences
  • Assistance before, during and after a train operation
  • Support in transport planning
  • Management of trains in rail network
  • Shunting of rail vehicles
  • Inspection, maintenance, elimination of faults and repair of rail network

Core business on the rail network

The operational and technical management of the network is the core business of ÖBB-Infrastruktur Betrieb AG. This company of the ÖBB Group operates, maintains and repairs a rail network with a length of just under 5,700km, ca. 70% of which is electrified and 35% in double track construction. In 2007, 97 million tonnes of goods and just under 200 million passengers were transported on this network. Specifically, ÖBB-Infrastruktur Betrieb AG is in charge of the following facilities:

  • 11,000km of tracks – of which 8,200km are electrified
  • 53,200 signals
  • 16,000 switches – of which 10,800 have remote control
  • 800 signal boxes – of which 200 are electronic
  • 5,800 bridges and viaducts
  • 260 tunnels and galleries
  • 5,900 railway crossings
  • 1,300 stations and stops – of which 840 railway stations and 114 shunting yards

Other responsibilities include the inspection, maintenance and elimination of faults of the subordinate 110kV traction network with a length of ca. 2,000km, which in the federal capital Vienna is constructed as 55 kV cable network.

Infra Service Division

The Infra Service Division is in charge of the technical management and reliable provision of these facilities. The strategy of a safe and cost-effective provision of the facilities is to reliably ensure a process-oriented and holistic maintenance. Therefore, Infra Service is responsible for the maintenance of the railway infrastructure facilities. This includes both structural facilities (substructure, superstructure, constructive engineering) and line equipment (power supply, safety engineering systems, telecom equipment for train operation).

The main tasks of the Infra Service division include:

  • Inspection/maintenance
  • Elimination of faults
  • Ensuring free passage through routes and train paths including winter service
  • Technical management

To ensure optimal availability of the facilities, one must also be able to quickly react and act in case of any faults. For this purpose, the Infra Service Division operates a central fault management. This system is installed throughout Austria in four Regional Control Centres and is serviced around the clock by the operators of the 15 kV overhead line management. The operators receive the fault reports and are in charge of the fault elimination process.

Topographical challenge

The particularities of the alpine geography represent a challenge when it comes to servicing this railway network. This is what distinguishes the Austrian railway network from many others in Europe. Risks emanating from mountain torrents, avalanche paths and rockfaces require specific safety measures and expertise. Thus, there is a special ‘Natural Hazard’ team, which safeguards the railway infrastructure against natural events such as avalanches, mudslides and debris flows or storms, which are particular phenomena of the inner-alpine region. Avalanche and rockfall barriers as well as mountain torrent and bank protection facilities are serviced. ÖBB is a European pioneer in the use of a sophisticated Weather Information System (WIS). Forecasts of heavy rains, storms and snowfalls as well as river water level queries allow to detect early when action is required. Prevention means to be prepared for events and not to be caught off-guard.

Rail Wear behaviour

Due to this geographical situation, the ÖBB railway network has a large share of narrow curves and sections with steep longitudinal gradients. 43% of the track is curved. This results in a high lateral wear of the rails that increases the necessity of their replacement. Rail grinding is the second most important maintenance measure on the rails. Rail grinding mostly becomes necessary due to the following wear mechanisms: in narrow curves, the phenomenon of rail corrugations occurs – particularly in tracks showing signs of fatigue in the fastening system. Due to the strong contact forces, there are changes in the rail cross-section affecting the stability of the horizontal running of the wagons in straight tracks. The parameter equivalent conicity reflects this behaviour and has been derived from the measured rail cross profile since 2001. Increased problems with rolling contact fatigue (head checks) also increase the necessity for grinding.

Inspection of tracks with permanent way measuring coach EM 250

Infra Service is among the world leaders in the use of track measurement systems. Several times a year, the permanent way measuring coach EM 250 checks the condition of the tracks with a non-contact measuring system and a measuring speed up to 200km/h.

The integrated inertial measuring system, Applanix POS/TG, allows high precision measurements of the track geometry. Apart from measuring the track geometry quality, the wear of the rail cross profiles is checked with the rail profile measurement system ORIAN 6 + HR and the roughness of the rail surfaces is controlled with the corrugation system. Since 2001, the raw data of each test run is transferred to the database of ÖBB-Infrastruktur and made available as a support to the service engineers in charge of maintenance planning. This data allows the optimal long-term planning of maintenance works. Thus, it was possible to considerably reduce the exceedance frequency of the intervention thresholds for the depth of corrugated rails and equivalent conicity in the last years.

The rail profile measurement system ORIAN 6 + HR

The rail cross profile measurement system ORIAN 6 + HR is a modern optical rail profile measurement system with integrated profile analysis and online conicity analysis.

The bases of this measurement system are four class 3b lasers operating in the hidden band. Over a period of less than 100 microseconds, an array is generated on the interior and exterior of each rail.

Corrugation measurement system

Since 2005, a rail surface measurement system based on laser distance measurement is used on the EM 250. With it, a scan of the rail surface is made every 5mm. Through an optimised algorithm a peak-to-peak value is derived every 25cm from the original measurement signal (filtering according to rail grinding guidelines 3cm-30cm) and displayed on the measuring coach as well as transferred to the database of Infrastruktur. The measurement is based on a laser chord distance measurement with an asymmetrical scan.

Rail grinding works

The grinding works are performed in the network of ÖBB with the Speno rail grinding machine type RR24M14 and RR16MS2.

Rail grinding

  • Surface treatment and reprofiling of rails in an area of +5° to -70°
  • RR24M14 – 24 rotating discs
  • ca. 3000m rail per shift

Switch grinding

  • RR16MS2 – 16 rotating discs
  • ca. 6 – 8 switches or 1700m rail per shift

By complying with the tight grinding tolerances, an optimal wheel-rail contact is regained and rail surface faults are eliminated. ÖBB-Infrastruktur Betrieb AG performs grinding works on ca. 500km of rails and 400 switches every year.

Inspection of the catenary system with the electrotechnical measuring car

In order to be able to check the condition of the catenary system after construction and also during the entire life cycle, the Infra Service Division operates an electrotechnical measuring car. This measuring car serves to control the quality parameters zigzag, contact wire height and the interaction between the overhead contact system and the current collector of the traction vehicle. The measurements are performed both with a non-contact measuring system and with a pantograph. The respective deadlines and limit values are included in the maintenance plan for energy equipment, which is based on the international standards.

A laser measurement system is used for non-contact measuring. The system, which is installed on the measurement car roof, works according to the ‘laser radar’ principle, i.e. an intensity modulated laser beam is scanned transverse to the direction of travel via a galvanometrically driven plane mirror. The laser beam is reflected by the overhead line. The contact wire height is measured through the phase difference between sent and received laser beam and the contact wire position (zigzag) through the position angle of the galvano scanner.

A force measuring system is used for the assessment of the dynamic interaction between the overhead line and the current collector. The measuring system, built on a single-arm pantograph, type Siemens 8 WLO 127-6YH84-9 (ÖBB-8e- AS), consists of measuring sensors to the force sensor of the vertically working forces, accelerometers to measure the vertical accelerations, force sensors to measure the forces working in the direction of travel, inertia sensors to monitor chains entering from the side, as well as accelerometers in the base frame of the overhead line to measure accelerations with vertical effect on the vehicle and systems to measure the current collector height.

The data acquired in a test run is analysed with a data visualisation and analysis programme and serves as a basis for the determination of suitable repair and maintenance measures.

New maintenance vehicle

The technical configuration of the infrastructure facilities requires available expertise and the capacity to act in several areas. Substructure, superstructure, bridge construction, overhead line, signalling equipment/systems engineering, and telecommunication are the areas of expertise required for servicing a technical rail infrastructure. Before ÖBB was restructured into a group of several independent companies, the aim was to merge these competences on an organisational and HR level. Already today, this merging of different, historically developed specialist areas and cultures has achieved the forecasted results. The joint, cross-facility utilisation of stoppages for inspection, maintenance or repair works is absolutely essential for an efficient maintenance strategy. With determination, ÖBB-Infrastruktur Betrieb AG is now implementing for the technical equipment what has already been achieved in the organisational and HR area. This specifically concerns ÖBB’s new maintenance vehicle, which can be used for as many facility groups as possible throughout the year. This equipment allows the cost-effective performance of the required processes (inspection, maintenance, elimination of faults, on-the-spot repair as well as ensuring the free passage through routes/train paths) across all facilities. ÖBB has started a programme to procure a total of 19 of these maintenance vehicles from Robel Bahnbaumaschinen GmbH for the activities of ÖBB-Infrastruktur Betrieb AG.

Design of the maintenance vehicle

The new maintenance vehicle is a two-axle vehicle, which is powered by a 440 kW low-noise and low-emission engine with a particulate filter system. The traction drive is based on a hydro-dynamic drive concept, with an additional hydrostatic traction drive for work runs. This drive concept allows the possibility to also use the vehicle for shunting and delivery transport tasks. The maximum admissible speed for self-propulsion and runnability when incorporated in a train is 100km/h. The vehicle is equipped with a driver’s cab for a maximum of seven people (driver plus six people) and an adequately dimensioned loading area for material and tool transports. There is also a lockable space for the storage of grounding poles and an aluminium ladder. The vehicle is equipped with PZB 90 (punctiform automatic train controls) as well as a digital train radio system and prepared for the retrofitting with the train safety system ETCS Level 2 (European Train Control System).

Additional equipment for cross-facility works

To ensure that works can be performed successfully across all facilities, the new maintenance vehicle is equipped with the following important features:

  • Crane – with a hydraulic boom extension of up to 17m including remote control, a detachable crane cab, endless rotator, timber and rail sleeper grab, load crossbeam, lopping shears, working platform and forestry mulcher to keep the clearance and line of sight free
  • Pantograph – with adjustable contact pressure (50 to 250 N) including illumination.
  • Contact wire measuring instrument for zigzag path and contact wire height, including recording
  • Winter service equipment including snow plough with ejection chute and associated power pack, track plough for retracing and an adapter plate for snow brushes to clean switches

A total of seven maintenance vehicles have been delivered to date. The remaining vehicles will be delivered by the end of 2009, at which point the advantages of the cross-facility work will take full effect on the entire ÖBB rail network. The use of this all-purpose maintenance vehicle will allow a considerable increase of productivity in maintenance, as well as improved work safety and quality.

Maximum cost-effectiveness in maintenance

To ensure the required availability of the technical facilities with maximum cost-effectiveness is a constant challenge for every rail infrastructure operator. Rail engineering expertise, well trained and motivated staff, a trend-setting demand-oriented maintenance strategy and, last but not least, technical equipment which can be used for as many facility groups as possible throughout the year, are all required to achieve this goal. We are convinced that the use of the intelligent measuring systems of our recording cars (substructure recording car EM 250 and electrotechnical measuring car) as well as the new maintenance vehicles ‘Track Vehicle 54.22’ will give maximum support in meeting these requirements.

About the author

Alfred Gruber

Authorised officer Dipl.-Ing. Alfred Gruber started his career in 1980 as administrator of 16.7 Hz traction power plants and became an expert on energy supply and network management. In 2000, he was promoted to Head of the Division Power Network and in 2003 of the Track System Division. Alfred Gruber considerably contributed to the strategic development of ÖBB-Infrastruktur. Since 2005, Alfred Gruber is in charge of the Infra Service Division in the restructured ÖBB Group, which is responsible for the cost-effective maintenance of ÖBB’s rail infrastructure facilities.