Thomas Nordmark

Condition monitoring at the wheel/rail interface for decision-making support

Many railway assets, such as wheels, suffer from increasing deterioration during operation. Good condition monitoring based on good decision-making techniques can lead to accurate assessment of the current health of the wheels. This, in turn, will improve safety, facilitate maintenance planning and scheduling, and reduce maintenance costs and down-time. In this paper, wheel/rail forces are selected as a parameter (feature) for the condition monitoring of wheel health. Once wheels are properly thresholded, determining their condition can help operators to define maintenance limits for their rolling stock. In addition, if rail forces are used as condition indicators of wheel wear, it is possible to use measurement stations that cost less than ordinary profile stations. These stations are located on ordinary tracks and can provide the condition of wheelsets without causing shutdowns or slowdowns of the railway system and without interfering with railway traffic. The paper uses the iron-ore transport line in northern Sweden as a test scenario to validate the use of wheel/rail forces as indicators of wagon and wheel health. The iron-ore transport line has several monitoring systems, but in this paper only two of these systems will be used. Wheel/rail force measurements are performed on curves to see how the vehicle negotiates the curve, and wheel profile measurements are done on tangent track not far away. The vehicles investigated are iron-ore wagons with an axle load of 30 tonnes and a loaded top speed of 60 km/h. The measurements are non-intrusive, since trains are moving and assets are not damaged during the testing process.

Identifying the root causes of damage on the wheels of heavy haul locomotives and its mitigation

The paper illustrates how damage patterns in the form of rolling contact fatigue (RCF) on wheels, can be employed to identify and improve underlying operational conditions. The focus is on RCF of locomotive wheels operating on the Iron Ore Line in northern Sweden and Norway. Seasonal changes and damage patterns are charted. Potential root causes for observed damage patterns are identified and investigated. Mitigating actions are proposed and the efficiency of implemented actions is quantified.

Reliability and measurement accuracy of a condition monitoring system in an extreme climate: A case study of automatic laser scanning of wheel profiles

The Iron Ore Line (Malmbanan) is a 473 km long track section located in northern Sweden and has been in operation since 1903. This track section stretches through two countries, namely Sweden and Norway, and the main part of the track runs on the Swedish side, where the owner is the Swedish Government and the infrastructure manager is Trafikverket (the Swedish Transport Administration). The ore trains are owned and managed by the freight operator and mining company LKAB. Due to the high axle load exerted by transportation of the iron ore, 30 tonnes, and the high demand for a constant flow of ore and pellets, the track and wagons must be monitored and maintained on a regular basis. The condition of the wagon wheel is one of the most important aspects in this connection, and here the wheel profile plays an important role. For this reason an automatic laser-based wheel profile monitoring system (WPMS) has been installed on this line using a system lifecycle approach that is based on the reliability, availability, maintainability and safety (RAMS) approach for railways. The system was prepared and installed and is being operated in a collaborative project between the freight operator and infrastructure manager. The measurements are used to diagnose the condition of the wheels, and to further optimize their maintenance. This paper presents a study of the concepts and ideas of the WPMS, and the selection, installation and validation of the equipment using a system lifecycle approach that is based on RAMS for railways. Results from the profile measurements and validation are shown. The system’s reliability during performance in extreme climate conditions, with severe cold and large quantities of snow, is presented. Then the benefits, perceived challenges and acquired knowledge of the system are discussed, and an improved V-model for the lifecycle approach is presented.

Guest editorial of Special Issue on High Tech in Heavy Haul

The International Heavy Haul Association (IHHA) is ‘dedicated to the pursuit of excellence in heavy haul railway operations, engineering, maintenance, and technology. It strives to accomplish this mission through the acquisition of knowledge relevant to this goal by sponsoring and organizing international and regional conferences, specialist technical sessions and specialist seminars; by commissioning guideline manuals, by preparing and distributing conference proceedings and technical documentation’. The IHHA has member organizations from Australia, Brazil, Canada, China, India, Norway, Russia, South Africa, Sweden, and the USA. The IHHA organizes a main international conference every fourth year. In 2005 the conference was held in Rio de Janeiro and the next conference will be held in Shanghai in June 2009. In between these main conferences, so-called Specialist Technical Sessions (STS) are organized; in 2003 in Dallas, USA, and in 2007 in Kiruna, Sweden. See www.ihha.net for more information. The IHHA STS 2007 was held from the 11th to the 13th of June 2007 in Kiruna in the northern part of Sweden. Kiruna is an iron ore mining town with a heavy haul railway line (Iron Ore Line – Malmbanan) annually bringing some 25 million tonnes of iron ore pellets to Narvik on the Atlantic Sea and to Luleå on the Baltic Sea. The local organizing of the IHHA STS 2007 was performed by co-operation between the mining company LKAB, the Swedish National Rail Administration (Banverket), the Railway Technical Research Centre of Luleå Technical University, and the Conference Enterprise Kiruna Congress. The IHHA STS 2007 was presented in the June 2007 issue of the journal Railway Gazette International under the theme ‘Heavy haul in the frozen north’. Fittingly, this issue has an iron ore wagon from Kiruna on the front page. The issue also contains an article entitled ‘Managing rail degradation on the Malmbanan’ written by Thomas Nordmark and Per-Olof Larsson-Kråik who were the main organizers of the conference. The IHHA STS 2007 had the theme ‘High Tech in Heavy Haul’ and featured some 400 delegates from 22 countries. Some 80 high-quality presentations were given in plenary and three parallel sessions. Invited keynote lectures were given by Björn Paulsson (Banverket, Sweden) and Semih Kalay (Transportation Technology Center, USA). Conference proceedings were distributed: both printed (772 pages) and as a CD. In parallel to the presentations, an exhibition was arranged in which some 40 companies and other organizations presented themselves. The present Special Issue has been established by inviting the authors of some selected technical presentations at the IHHA STS 2007 to submit their papers to the Journal of Rail and Rapid Transit for a further international peer-review. From a total of 16 papers this review process finally selected 11 papers for publication. The papers bring up mainly technical subjects important for efficiency, economy, and safety, such as running performance and wheel–rail interface issues and aspects of monitoring systems. Finally, we would like to express our appreciation to the Journal of Rail and Rapid Transit Board and the IHHA International Committee for co-operation in realizing this Special