Defective railway wheels can cause severe damages to both track and vehicle items, which in worst case can lead to derailments with extensive losses. Wheel impact detection systems are intended to support prevention of railway damages and its related losses, through recognition of wheel defects and generation of alarms. While commissioning of a wheel impact detection system in Sweden, it was revealed that the detection system was reliable as they were not generating any false alarms. However, during operation some of the system's alarms resulted in No Fault Found (NFF) events. Hence an investigation was launched to determine if the cause of the NFF events were false alarms generated by the detection system, or the inability of subsequent manual inspection to replicate the detection system's test result. This paper presents experiences from the verification study and links these to international experiences illustrating how wheel impact detection systems can support continuous assessment of wheel condition and related condition based maintenance efforts.

The purpose of this paper is to identify stakeholders' need for system condition information in order to improve railway punctuality. The paper provides a holistic formulation of maintenance-related punctuality problems within the interface between the contact wire and the pantograph. From the identified problem formulation, the information needed to support the maintenance of technical functions can be identified. The incorporated system and stakeholder perspective adds a dimension to the explanation of what information is needed and why it is needed. The system and stakeholder perspective on the assessment of the information need can serve as decision support when acquiring new condition monitoring technologies. On the basis of the problem formulation, this perspective can also serve as an illustration of how information is to be used to improve punctuality. In order to identify stakeholders' need for system condition information, a failure mode and effects analysis (FMEA) approach was used. The FMEA is complemented with information derived from informal interviews performed with a variety of experts working with issues related to contact wires and pantographs. The applied methodology can be useful for conducting further research studies on other stakeholder and engineering interfaces, such as the wheel-rail interface.

Due to the increasing need for transportation and environmental concerns, there is a social and political will to transfer transportation services from roads to rail. The increasing demand for railway transportation services has a significant effect on important stakeholder requirements, such as safety, punctuality, dependability, sustainability and costs. This in turn affects railway practices concerning operation, maintenance and modification. Simultaneously, the ongoing deregulation of state-owned railways has caused new organizations to enter the railway sector. Hence, the punctuality of the railway is dependent on a combination of multiple required functions that are concurrently provided by different stakeholders, e.g. the infrastructure manager, infrastructure maintenance contractors and traffic operators. In Sweden, Banverket (the Swedish National Rail Administration) is the infrastructure manager and has the overall responsibility for railway punctuality. This means that Banverket has to coordinate and stimulate the stakeholders to provide the required functions in order to achieve the delivery of punctual transportation services. The purpose of this research is to explore and describe how information about the condition of technical systems can support stakeholders within the Swedish railway in improving punctuality by means of more effective and efficient maintenance. The focus is on delays that are caused by the absence of required infrastructure functions, even though the interaction with the rolling stock is considered through the study of critical interfaces. Condition monitoring technologies are focused on as the primary application for obtaining condition information on technical systems. Hence, the research is intended to provide knowledge about how condition information can be used in the quest to provide the quality required from the Swedish railway transportation service at an adequate cost for society. To fulfil the stated purpose, empirical data have been collected by document studies, interviews, work-shops, observations and field measurements. Examples of covered data are train delay statistics, failure statistics, No-Fault-Found events and wheel impact forces. The data have been analysed through statistical and analytical approaches (e.g. Failure Mode and Effects Analysis, FMEA), as well as by applying theories related to principal agent problems, Scientific Management and international dependability standards. The thesis describes how the maintenance effort required by infrastructure maintenance contractors is affected by the maintenance effort conducted by traffic operators (and vice versa). The interaction between infrastructure and rolling stock has a significant effect on the systems' punctuality and the degradation of bound capital. Hence, effective punctuality improvements through maintenance efforts must be based on a holistic railway system perspective, i.e. a joint consideration of infrastructure and rolling stock. The thesis also presents how condition information can be used as a management tool to stimulate the fulfilment of performance requirements made on railway stakeholders. It is also shown that the same information can be used to predict and plan necessary preventive maintenance tasks, as well as to support continuous improvement of the technical systems. However, unless stakeholder needs are acknowledged and unless proper scientific investigations precede the formation of requirements and the applications of condition monitoring technologies, it is likely that the desired system performance improvements will not be realised. In summary, the thesis outlines a possible scenario in which condition information could support railway stakeholders in improving the punctuality of the railway system by means of more effective and efficient maintenance.

Det ökande behovet av transporter samt en ökande miljömedvetenhet har ökat efterfrågan på och nyttjandet av järnvägstransporter. Det ökande behovet av järnvägstransporter har en signifikant påverkan på viktiga intressentkrav såsom säkerhet, punktlighet, tillförlitlighet, hållbarhet samt kostnader. Detta påverkar i sin tur järnvägens tillämpningar beträffande drift, underhåll och modifieringar. Samtidigt har den pågående avregleringen av järnvägen medfört att nya organisationer har kommit in på järnvägsmarknaden. Följaktligen är punktligheten på järnvägen beroende av en kombination av många krävda funktioner som för närvarande är tillhandahållna av olika intressenter, till exempel infrastrukturhållare, underhållsentreprenörer för infrastruktur och trafikoperatörer. I Sverige är Banverket infrastrukturhållaren.Syftet med denna forskning är att utforska och beskriva hur information beträffande tekniska systems hälsa kan stödja intressenter inom den Svenska järnvägen till att förbättra punktligheten genom ett effektivare underhåll. Fokus ligger på förseningar som är orsakade av frånvaro av krävda infrastrukturfunktioner, även om interaktion med rullande materiel beaktas genom studier av kritiska gränsytor. Tillståndsövervakningsteknologier är fokuserade som den primära applikationen för erhållandet av information om de tekniska systemens hälsa. Därmed är forskningen avsedd att bidra med kunskap om hur tillståndsinformation kan användas för att tillhandahålla krävd transportservice på den svenska järnvägen till en adekvat kostnad för samhället. För att tillfredställa syftet med forskningen har data inhämtats genom dokumentstudier, intervjuer, seminarier, observationer och fältmätningar. Exempel på avhandlad data är; tågförseningsstatistik, felrapportstatistik, inget-fel-funnet-händelser (No-Fault-Found, NFF) samt hjulkrafter. Data har analyserats genom statistiska och analytiska ansatser, till exempel felmod- och effektanalys (FMEA), men även genom teorier relaterade till principal-agent-problemet, Scientific Management och internationella tillförlitlighetsstandarder.Avhandlingen beskriver hur den av en underhållsentreprenör krävda underhållsinsatsen påverkas av det underhåll som trafikoperatörer utför (och vice versa). Detta har en signifikant påverkan på systemets punktlighet samt degraderingen av bundet kapital. Följaktligen så måste effektiva punktlighetsförbättringar genom underhållsinsatser baseras på ett holistiskt järnvägssystemperspektiv, till exempel ett gemensamt beaktande av infrastruktur och rullande materiel. Avhandlingen visar också hur tillståndsinformation kan användas som ett ledningsverktyg för att stimulera uppfyllandet av prestationskrav lagda på järnvägsintressenter. Det är också illustrerat att samma information kan användas för att prediktera och planera nödvändiga förebyggande underhållsåtgärder likväl som att stödja kontinuerlig utveckling av det tekniska systemet. Emellertid, om intressenternas behov inte tillkännages och om inte vederbörliga vetenskapliga utredningar föregår utformandet av krav samt tillståndsövervakningsapplikationerna, är det troligt att de eftersträvansvärda systemprestandaförbättringarna uteblir. Sammanfattningsvis så bidrar avhandlingen med ett möjligt scenario för hur tillståndsinformation kan stödja järnvägsintressenterna till att förbättra punktligheten hos järnvägssystemet genom effektivare underhåll.

Defective rail wheels can cause severe damages to both track and vehicle components, which in worst case can lead to derailments with extensive losses. Wheel impact detection systems are intended to prevent railway damages and its related losses, through recognition of wheel defects and generation of alarms. At commissioning of a wheel impact detection system in Sweden, the commissioning study showed that the system was reliable, without generating any false alarms. However, during operation some of the system's alarms resulted in No Fault Found (NFF) events at subsequent manual inspections. Hence, a verification study was launched in order to determine if the cause of the NFF events were false alarms generated by the system, or the inability of subsequent manual inspection to replicate the system's test result. The verification study was expected to support an exclusion of the manual inspection, which was perceived to be the cause of the NFF events. However, an exclusion of the manual inspection would require the wheel impact detection system to be highly reliable, since it would be the primary foundation for decisions about both operation and maintenance. This study reports on vital experiences from the verification study and links these to experiences from other countries. The experiences highlight the importance of data accuracy and appropriate information management, in order to achieve the potential benefits and avoid the drawbacks of condition monitoring.

Banverket (‘the National Swedish Railway Administration') is responsible for management of the infrastructure in Sweden. The main objective of Banverket, stated by the Swedish government, is to assure a cost-effective and long-term provision of transportation for citizens and the business sector. In order to stay competitive with other forms of transportation, the railway needs to be cost-effective and provide reliable service. The reliable service is to a great extent reflected in terms of train punctuality. Railway components in general have a fairly long life, which means that the cost effectiveness of the transportation system is highly dependent on the effectiveness (doing the right things) and the efficiency (doing the things right) of its operation and maintenance process. The purpose of maintenance is to ensure business objectives through the assurance of required technical functions. Maintenance in the railway ensures the function of the systems that are es-sential for the operation of the transportation system. In other words, maintenance is a vital tool for achieving punctuality, which next to safety is Banverket's most important goal area. Developments in sensor technology and in the information and communication technology sector have provided new opportunities to use technology to assess infrastructural and rolling stock conditions. Decision support derived from condition monitoring systems can provide opportunities for improved maintenance management. In other words, condition monitoring can provide conditions for improved maintenance effectiveness and efficiency and hence punctuality. The thesis explores three areas. The first area is the exploration of current train delay statistics, performed in order to assess how the statistics can represent the influence of different factors on punctuality. The second is an exploration of the link between punctuality and maintenance and more specifically condition monitoring. The third area explores current condition monitoring applications at Banverket to form a knowledge foundation for further condition monitoring implementations intended to improve the reliability and hence the punctuality of the transportation system. In the perspective of the studies are important factors for successful applications of condition monitoring technology proposed. These are factors such as knowledge of problem characteristics, information accuracy, measurement limitations and ability to combine condition based maintenance objectives with business objectives etc. Furthermore, are recommendations for future condition monitoring implementations made. These are recommendations for enhancing the condition-based maintenance, which in turn is dependent on applications of condition monitoring. The final discussions are based upon overall experience from working with the material. The discussion links to the initial research problem, whose intension is to widen the horizon of possible condition monitoring applications.

Governmental regulations state that the Swedish national railway administrator Banverket has an overall responsibility for train punctuality, independent of whether train delays are caused by Banverket or the train operating companies. Banverket is responsible for the functioning of the railway system as a whole, but can with own maintenance and reinvestment activities only affect the infrastructure. Conflicts derive from the two stakeholders' different roles and interests. In order to effectively forecast maintenance needs and costs of the infrastructure, Banverket want that the infrastructure's deterioration caused by the rolling stock should be both as small and as predictable as possible. However, the train operating companies look at the same situation from the other point of view, with a focus on their rolling stock. The interrelationship between the two stakeholder roles and their combined maintenance process is complex, since it is difficult to pinpoint the responsibility for the whole transport system and separate assets. One essential approach, in order to monitor low performance linked to responsible stakeholder roles and causes is to follow up the two measures punctuality and train delays. This paper explores the characteristics of existing train delay statistics and describes risks when maintenance efforts and design of incentives for improved railway operation is based on statistics that does not reflect the true root-causes of problems.

Effektivt förebyggande underhåll leder till en kostnadseffektiv järnvägsinfrastruktur. Det är möjligt att förutse ett kommande haveri hos komponenter om dess tillstånd kan fastställas genom mätningar med sensorer. Oförutsedda fel hos komponenter inom infrastrukturen leder till många tågförseningar. Om felaktigheter hos komponenter kan förhindras kommer det att bidra till ökad punktlighet. DISA (Driftövervakning I SignalAnläggningar) är ett tillståndsövervakningssystem utvecklat av Banverket Projektering. Systemet är installerat som en pilotanläggning vid Abisko Östra station Nora Banregionen (bandel 111). Disa har sedan installationen i maj 2003 samlat tillståndsdata för spårväxlar och signallampor. Vissa parametrar som DISA mäter i ställverket kan också extraheras från Norra Banregionens tågdriftledningssystem Argus. En studie utfördes för att fastställa huruvida det är möjligt att använda sig av indikeringsparametrar från Argus för att erhålla information som är likvärdig med DISAdata. Mycket pengar kan sparas genom att ur befintliga system extrahera tillståndsdata om datakvalitén är tillfredställande. Denna rapport beskriver resultaten från DISA och Argus mätningarna och presenterar en analys av insamlat data för fastställande av status för de övervakade objekten. Rapporten inkluderar även en diskussion beträffande om och hur systemen kan användas som tidigvarningssystem. Resultatet av DISA utvärderingen är att systemet i dagsläget brister i så många punkter att det idag inte går att använda som underhållssystem. Vad Argus beträffar så finns det möjlighet att ur systemet plocka ut tillförlitliga värden på brinntider för signallampor och tillförlitliga värden på antalet omläggningar för spårväxlar.