The measurement and improvement of track quality are key issues in determining both the restoration time and cost of railway maintenance. Applying the optimal tamping strategy helps reduce maintenance costs, making operations more cost effective and leading to increased safety and passenger comfort. In this paper, track geometry data from the iron ore line (Malmbanan) in northern Sweden, which handles both passenger and freight trains, are used to evaluate track geometry maintenance in cold climate. The paper describes Trafikverket’s (Swedish Transport Administration) tamping strategy and evaluates its effectiveness in measuring, reporting, and improving track quality. Finally, it evaluates the performance of the maintenance contractor and discusses the importance of the functional requirements stated in the outsourcing contracts.

The measurement and improvement of track quality are key issues in determining the time at which railway maintenance must be performed and its cost. Efficient track maintenance ensures optimum allocation of limited maintenance resources which has an enormous effect on maintenance efficiency. Applying an appropriate tamping strategy helps reduce maintenance costs, making operations more cost-effective and leading to increased safety and passenger comfort levels. This paper discusses optimisation of the track geometry inspection interval with a view to minimising the total ballast maintenance costs per unit traffic load. The proposed model considers inspection time, the maintenance-planning horizon time after inspection and takes into account the costs associated with inspection, tamping and risk of accidents due to poor track quality. It draws on track geometry data from the iron ore line (Malmbanan) in northern Sweden, used by both passenger and freight trains, to find the probability distribution of geometry faults.

Railway vehicles are efficient because of the low resistance in the contact zonebetween wheel and rail. In order to remain efficient both train operators and infrastructureowners need to keep rails, wheels and vehicles in acceptable condition. Wheelwear affects the dynamic characteristics of vehicles and the dynamic force impact on the rail.

The shape of the wheel profile affects the performance of railway vehicles in differentways. Wheel condition has historically been managed by identifying and removing wheels from service when they exceed an impact threshold.

Condition monitoring ofrailway vehicles is mainly performed using wheel impact load detectors and truck performance detectors. These systems use either forces or stress on the rail to interpret the condition.

This paper will show measurements taken at the research station outside Luleå innorthern Sweden. The station measures the wheel/rail forces, both lateral and vertical,at the point of contact in a curve with 484 m radius at speeds up to 100 km/h. Dataare analyzed to show differences for various wheel positions and to determine therobustness of the system.

Denna rapport beskriver resultaten från projektet ”Från mätdata till underhållsbeslut” där avdelningen för drift och underhållsteknik/JVTC vid Luleå tekniska universitet på uppdrag av MTAB följt hjulslitaget på två malmvagnar under ett års tid. Under perioden har vagnarnas rälkrafter registrerats vid JVTC:s forskningsstation i Sävast.

One of the major failure modes in the railway industry is wheel wear. Wheel wear affects the dynamic characteristics of vehicles and the dynamic force impact on the rail, and can in worst cases scenario cause derailment. The wheel conditions also influences the wear and required maintenance on the rail. In this paper the correlation of wear rate and dynamic force between wheel and rail is studied to specify the most costeffective wheel maintenance interval. Two cars, total of sixteen wheels, were selected.

In order to calculate the wear trend, measurements have been performed, by MiniProfTM, for a period of 12 months with the cars in traffic. During the same time period, the trend of track forces from the two cars has been obtained from the research station, outside Luleå, Sweden. Using the trends from wheel wear and track force in combination to form maintenance planning for wheels are discussed.