Km Of Track Research Articles

The Influence of Seasonal Effects on Railway Vertical Track Modulus

Adequate vertical track support is essential for safe and efficient railway operations. Insufficient support leads to distorted track geometry, increased dynamic loads, component stress, poor ride quality, rolling stock damage, and derailment risks. Current inspection practices focus on assessing the condition of the track components and geometry, rather than the root causes of degradation. To improve this condition, this study presents the use of a methodology that utilizes an autonomous vertical track deflection measurement system mounted on a loaded rail car (36 tonnes/axle) to support track maintenance decisions in a heavy haul railroad located in southeast Brazil. The system continuously measured substructure stiffness along the railway line. Over one year, data were collected from over 8000 km of track. The study highlighted seasonal effects on track degradation over time, identifying areas with significant deflections and high deflection rates, which contribute to issues such as differential settlement and reduced lifespan of track components. Additionally, the study revealed seasonal effects, with deflections peaking during wet weather and decreasing during dry cycles. A method to classify weak track areas was developed, facilitating monitoring and enabling more effective maintenance planning, contributing to the reduction of overall track maintenance costs and enhancing safety and operational efficiency.

Expanded statistical analysis of squats on the Great Britain (GB) mainline network

Squat defects are one of the most common rail surface defects. Significant research effort has gone into understand squat defects over the last 10 years which has brought about important developments in the understanding of their initiation mechanism; however, further work is still required to fully understand squat and the best methods to control them.This study considers records of squat defects over a period 9 years, considering 2600 km of track across 8 different routes on the GB mainline network. The analysis separately reviews squats on: plainline, crossings, joints and welds. Results include an overview of the main factors influencing the development of each type of squats, practical methods to immediately reduce and manage squat defects and recommends focus areas for further research to understand squat defects.Results suggest that squats on plainline, crossings, joints and welds, all correlate with different influencing factors; headcheck defects appear to significantly influence the probability of squats and how other factors influence squat development.There is a strong connection between total head wear rate (combined material removal due to traffic and grinding) and squats; 90 % of all squats appear on rail with a headwear rate of <0.2 mm/year. Overall larger section rail (60 kg/m vs 56 kg/m) and harder material (260 Brinell vs 220 Brinell) is significantly less susceptible to squat damage. Track curvature has an influence of squat development, especially in rail with no headcheck cracking, where the tightest curves are significantly more likely to sustain squat damage. The probability of squat at vertical discontinuities, i.e. joints and crossings are significantly more likely as train speed increases. Whilst squats on joints are 1000 time more likely than squats on welds.

РАЗРАБОТКА РЕГРЕССИОННОЙ МОДЕЛИ ПАССАЖИРООБОРОТА ВОЗДУШНОГО ТРАНСПОРТА РОССИЙСКОЙ ФЕДЕРАЦИИ ДВУМЯ АЛЬТЕРНАТИВНЫМИ МЕТОДАМИ

The article describes a regressive mathematical model of passenger turnover in the air transport of the Russian Federation. The following are used as independent variables: the average flight costin the economy class of an aircraft per 1,000 km, the average monthly nominal accrued wages of employees in a full range of organizations, the average fare for travel in a second-class carriage of an express unbranded long-distance train per 100 km of track, the working population. Model parameters are identified using two alternative methods of regression analysis: mixed estimation and maximum consistency between the calculated and actual values of the output variable. The constructed versions of the model fully correspond to the content meaning of the independent variables included in their composition and have high accuracy. To solve the problems, the researcher should select one of them according to their features, namely, either the tendency to minimize the disrepancies between the predicted and actual values of passenger traffic in the future or the desire to identify future trends in the indicator's dynamics, possibly, with the greater accuracy.

Transport and geographic location of recreational and tourist centers as a factor in the development of tourism (on the example of Chernivtsi oblast)

The peculiarities of the transport and geographical position of Chernivtsi oblast and the possibilities of its use for the development of tourism and recreation are analyzed. The possibilities of transport connection of the region with other regions of Ukraine and foreign countries are investigated. Some aspects of the location of individual recreational and tourist centers of the region relative to the most important transport highways in the context of the transfer of tourists to the main destinations are revealed. Transport services are an integral part of the tourist product and an important factor in the development of tourism in the region. The transport accessibility of the most popular tourist facilities depends on the level of development of the transport complex, which in turn affects the price of the tourist product, its quality and the final impressions of tourists from visiting tourist places. One of the key factors affecting the development of the transport complex of the region is its transport and geographical position. The influence of this factor is first of all revealed in the location of the region relative to the main international and important national routes of communication, as well as in the distance and ease of communication from the main transport highways to the centers of recreational and tourist activity. Chernivtsi oblast, despite the size of the territory (the smallest by this indicator in Ukraine), has a favorable transport and geographical position in the context of tourism development. This is due to the following aspects: 1) A number of highways of international and national importance pass through the territory of the region, which continue in the neighboring countries – Romania and Moldova and other regions of Ukraine. The total length of public roads in the region in 2020 was 2.9 thousand km. Thus, there are more than 358 kilometers of highways per 1,000 km2 of the region’s area. 2) A fairly developed network of railway tracks has been formed in the region, within which a number of suburban and intercity railways operate. In 2020, the length of railway tracks in the region was 413 kilometers, or almost 51 km of tracks per thousand square kilometers of the region’s territory. 3) An international airport operates in Chernivtsi oblast center. This is the only facility in the region that allows air communication with other regions of Ukraine and countries of the world. Therefore, Chernivtsi oblast occupies a favorable transport and geographical position. This is primarily due to its border location and the availability of transport connections with Romania and Moldova, as well as a significant number of road and rail connections, an international airport in Chernivtsi. In general, the transport and geographical location of the main tourist and recreation centers is favorable for the development of tourism. However, the state of transport infrastructure, in particular most local roads, creates significant obstacles in the provision of quality tourist services. The most problematic aspect in this matter is the restoration of the bridge across the Prut River between the villages of Dubivtsi and Hlynnytsia. This will make it possible to significantly improve the road connection of recreational and tourist centers located in the southwestern part of the region with the M-19 and H-10 highways, which play the most important role for the arrival of tourists in the region. It is also important to increase the number of direct flights between the regions of Ukraine and with foreign countries, rail transport from Chernivtsi and to restore regular air flights.

Influence of the Analytical Segment Length on the Tram Track Quality Assessment

In the track quality analysis, numerical values representing the relative condition of track geometry called track quality indices (TQIs) are calculated along a specific track segment. Segments are defined as linear track geometry datasets with the homogeneous characteristics of factors affecting geometry degradation. The 200m-long analytical segment is used most often on inter-city conventional and high-speed rail networks. However, in the case of the small urban rail networks, the homogeneity of track-geometry degradation influential factors is very low. This segment length is usually too long for efficient track maintenance or reconstruction with minimal disruption of the urban traffic. This paper explores the effect of reducing the analytical segment length in the condition assessment of the tram network in the City of Osijek, Croatia. The research had two main objectives: (1) to assess the narrow-gauge tram-track geometry quality through the application of the established synthesized TQIs, and (2) to analyze how a change in the analytical segment length affects this assessment. Two synthesized track quality indices—one based on a weighted value and the other on a standard deviation of measured track geometry parameters—were calculated for the 27.5 km of tracks on consecutive 200-, 100-, 50-, and 25 m long analytical segments. The comparative analysis of the TQIs’ calculation results showed that the reduction in the segment length increased the resolution of the track quality analysis in both cases, while the index based on a weighted value of geometry deviations proved less sensitive to this reduction. These results contribute to further segmentation process establishment and TQIs implementation on tram infrastructure.

Aerial Footage Analysis Using Computer Vision for Efficient Detection of Points of Interest Near Railway Tracks

Object detection is a fundamental part of computer vision, with a wide range of real-world applications. It involves the detection of various objects in digital images or video. In this paper, we propose a proof of concept usage of computer vision algorithms to improve the maintenance of railway tracks operated by Via Rail Canada. Via Rail operates about 500 trains running on 12,500 km of tracks. These tracks pass through long stretches of sparsely populated lands. Maintaining these tracks is challenging due to the sheer amount of resources required to identify the points of interest (POI), such as growing vegetation, missing or broken ties, and water pooling around the tracks. We aim to use the YOLO algorithm to identify these points of interest with the help of aerial footage. The solution shows promising results in detecting the POI based on unmanned aerial vehicle (UAV) images. Overall, we achieved a precision of 74% across all POI and a mean average precision @ 0.5 (mAP @ 0.5) of 70.7%. The most successful detection was the one related to missing ties, vegetation, and water pooling, with an average accuracy of 85% across all three POI.

Reduction of vehicle exhaust gas toxicity due to brake energy recovery

BACKGROUND: In recent years, fleet of vehicles in the Russian Federation is on a significant increase, that leads to considerably amplified emissions of toxic gases into the atmosphere. The share of toxic gas emissions from motor vehicles ranges from 65 to 70%. In order to reduce the toxic gas emissions into the atmosphere, electric vehicles have been introduced, but they have a number of disadvantages. These are a limited mileage before recharging and expensive batteries. Also, works on the use of hydrogen as a fuel for cars are conducted at an accelerated pace. However, the issue of a hydrogen fuel storage has not yet been worked out. At the same time, the used fleet of vehicles continues to poison the atmosphere.&#x0D; AIMS: Studying the braking energy recuperator for decreasing carbonic oxide CO in exhaust gases of the UAZ car.&#x0D; METHODS: The construction of a combined unit with a gas-hydraulic braking recuperator was developed, which is installed on a UAZ vehicle (RF Pat. No. 2193977). Comparative studies were carried out in accordance with GOST 33670-2015 and GOST 52033-2003.&#x0D; RESULTS: Results of comparative studies of the car showed that a minimum of CO emissions is observed in high gear, at a speed of 1825 m/s, and CO emissions significantly increase in lower gears. The recuperator eliminates this drawback due to the additional power transmission to the driving wheels.&#x0D; CONCLUSION. When a car starts in the urban cycle, there is a minimum of CO emissions with a recuperator, at the same time the car acceleration increases, that reduces the acceleration time and the distance by 3035%. A car with a recuperator on average consumed gasoline up to 15 l per 100 km, and this parameter of the production car was up to 17,5 l per 100 km of track. Due to the recuperator, CO emissions are reduced by 16%.

Further development of F-index for fuzzy graph and its application in Indian railway crime.

From the mid-nineteenth century, the railway network has been the most important mode of conveying people and goods in India. 22.15 million passengers used this network and 3.32 million metric tons of goods were also shipped daily from 2019 to 2020. The national rail network comprised 126,366 km of track over a route of 67,368 km and 7,325 stations. It is the fourth-largest national railway network globally after the United States, Russia and China. But with the passage, they pose a threat to the general public while travelling, being the instances of crimes rising fourfold in rails. The ongoing railway crime has become a cause of concern for the common passenger now. In this article, F-index for fuzzy graphs is used to analyze the railway crimes in India and compared with three other topological indices. F-index for fuzzy graphs and the first Zagreb index for fuzzy graphs provide similar results whereas F-index for fuzzy graphs provides better realistic results than F-index for crisp graphs and first Zagreb index for crisp graphs to detect the crime in Indian railway. Also, this index is studied for several operations such as Cartesian product, composition, union and join of two fuzzy graphs. Some interesting relations of F-index are established during fuzzy graph transformations. Using those transformation, it is shown that n-vertex star has maximum F-index among the n-vertex trees. Also, maximal n-vertex unicyclic fuzzy graph having r cycle is determined with respect to F-index.

Generating unbiased estimates of burrowing seabird populations

Maximising survey efficiency can help reduce the tradeoff between spending limited conservation resources on identifying population changes and responding to those changes through management. Burrow‐nesting seabirds are particularly challenging to survey because nests cannot be counted directly. We evaluated a stratified random survey design for generating unbiased population estimates simultaneously for four petrel species nesting on Macquarie Island, Australia, where the survey cue, burrow entrances, is similar for all species. We also compared the use of design‐based and model‐based analyses for minimising uncertainty in estimates. We recorded 2845 Antarctic prion burrows, 306 white‐headed petrel burrows and two blue petrel burrows while distance‐sampling along 154 km of transects. For blue petrels and grey petrels, we completed nocturnal searches along a further 71 km and searched 249 km of tracks during follow‐up ground searches. We failed to generate unbiased population estimates for two rare and localised species, blue and grey petrels, from our stratified random survey. Only for the most widespread and abundant species, Antarctic prion, did the estimate have reasonable power to detect a rapid population change. Model‐based analyses of the stratified random survey data did not improve upon traditional design‐based analyses in terms of uncertainty in population estimates, but they did provide useful spatial representation of current populations. Models that used the targeted survey data did not reflect current population sizes and distributions of the two rare and localised species. We found that when species ecologies, distributions and abundances vary, a multi‐method approach to surveys is needed. Species with low abundance that occur patchily across large islands are likely to be best estimated using targeted surveys, whereas widespread and abundant species can be accurately and precisely estimated from randomised surveys using informative model‐based analyses.

Influence of Mountain Conditions on Road Fuel Consumption (Example of the Republic of Tajikistan)

Most of the highways of the Republic of Tajikistan pass in mountainous and high-mountainous regions at an altitude of 1500-3500 m above sea level. They are characterized by steep passes (slope up to 10-12%), a large number of turns (15-18 pieces per 1 km of track), small turning radii (8-15 m) and poor condition of the roadway (holes, bumps, clogging with stones). Difficult driving conditions lead to increased fuel consumption. On the basis of experimental studies, a mathematical model has been developed that takes into account the influence of various factors on the track fuel consumption of a truck. The experiments were carried out on heavy mining dump trucks: KamAZ-52212, BelAZ-7540V, Howo-ZZ3257N3847N1 and Shacman-SX3256DR384 during the construction of the Rogun HPP in the Republic of Tajikistan.

RESEARCH OF CONCRETE OF REINFORCED CONCRETE SLEEPERS, WHICH DECIDED DAMAGE DURING OPERATION

Purpose. On the railways of Ukraine in some areas there is an intensive premature exit sleepers due to the formation of defects that can affect the safety of trains and cause significant material losses due to a single replacement of a significant number of sleepers. The purpose of the study is to establish the causes of damage reinforced concrete sleepers on a characteristic section of the railway with their intense premature exit. Methodology. The condition of reinforced concrete sleepers of SB3 type under unlined substrate fastenings on 324-332 km of the pair track of the Odnorobivka-Bukine section of the Southern Railway was studied, where since 2007 their intensive output was observed due to defects. Findings. It is established that for 15 years of operation, as 236.3 million tons were put into operation, about 2.8 % of sleepers were replaced due to defects (44 pieces per 1 km of track). Typical defects (damages), due to which the sleepers were removed from the track, were mainly 13.2 and 13.2 according to the classification of CP-0150 – cracks and fractures of sleepers, including ones with crushing concrete. These defects were preceded by the formation of a network of thin cracks on the visible surfaces of sleepers. 3 sleepers with an initial compressive strength of 68…77 MPa produced by the Korosten Reinforced Concrete Sleeper Plant and the Gnivan Special Reinforced Concrete Plant, removed from the track due to characteristic defects, were selected and investigated. Samples were selected from the sleepers, with the help of which there was determined the final strength of concrete and microscopic examinations, including luminescence flaw detection method, were performed. It was found that the network of cracks in sleepers is spatial, mostly developed mostly beneath their top edge, the least developed above the bottom edge, and causes a decrease in compressive strength of concrete by 47…72 %. It is noted that the destruction of concrete during loading occurred behind these cracks. On the inner surfaces of the cracks there are individual grains of aggregates, which have signs of active silica content, that together with the nature of the cracks may indicate that the cause of their formation is corrosion of concrete from the interaction of cement alkali with reactive aggregates. On the surfaces of the cracks in the lower part of the sleepers leaching products were found, apparently leached by electro migration, which may indicate that corrosion processes were promoted by leakage currents on electrified DC tracks. Originality Thus, in the study area, the main cause of defects, which caused the replacement of the sleepers – was the corrosion of concrete due to the interaction of cement alkali with reactive aggregates, promoted by leakage currents, as well as a small diagram of sleepers and the use of unlined anchor intermediate rail fasteners. Practical value. The results of the study allow to establish the causes of cracks and other damage in reinforced concrete sleepers during operation and, in turn, reduce the losses of fasteners manufacturers and sleepers from defects and complaints, optimize the total cost of track repairs and subsequent track maintenance due to rational purpose of track construction, reduction of damage and replacement of sleepers during track operation.

Physical Disturbance by Bottom Trawling Suspends Particulate Matter and Alters Biogeochemical Processes on and Near the Seafloor

Bottom trawling is known to affect benthic faunal communities but its effects on sediment suspension and seabed biogeochemistry are less well described. In addition, few studies have been carried out in the Baltic Sea, despite decades of trawling in this unique brackish environment and the frequent occurrence of trawling in areas where hypoxia and low and variable salinity already act as ecosystem stressors. We measured the physical and biogeochemical impacts of an otter trawl on a muddy Baltic seabed. Multibeam bathymetry revealed a 36 m-wide trawl track, comprising parallel furrows and sediment piles caused by the trawl doors and shallower grooves from the groundgear, that displaced 1,000 m3 (500 t) sediment and suspended 9.5 t sediment per km of track. The trawl doors had less effect than the rest of the gear in terms of total sediment mass but per m2 the doors had 5× the displacement and 2× the suspension effect, due to their greater penetration and hydrodynamic drag. The suspended sediment spread &amp;gt;1 km away over the following 3–4 days, creating a 5–10 m thick layer of turbid bottom water. Turbidity reached 4.3 NTU (7 mgDW L–1), 550 m from the track, 20 h post-trawling. Particulate Al, Ti, Fe, P, and Mn were correlated with the spatio-temporal pattern of suspension. There was a pulse of dissolved N, P, and Mn to a height of 10 m above the seabed within a few hundred meters of the track, 2 h post-trawling. Dissolved methane concentrations were elevated in the water for at least 20 h. Sediment biogeochemistry in the door track was still perturbed after 48 h, with a decreased oxygen penetration depth and nutrient and oxygen fluxes across the sediment-water interface. These results clearly show the physical effects of bottom trawling, both on seabed topography (on the scale of km and years) and on sediment and particle suspension (on the scale of km and days-weeks). Alterations to biogeochemical processes suggest that, where bottom trawling is frequent, sediment biogeochemistry may not have time to recover between disturbance events and elevated turbidity may persist, even outside the trawled area.

An Overview on Railway Impacts on Coastal Environment and Beach Tourism in Sicily (Italy)

The main aim of this paper is to analyze the development of the railway network in Sicily (Italy), where it runs close to the sea on two of the three sides of the island, and give an overview of the related impacts on coastal environment and tourism. In order to achieve such an objective, the impacts of the railway network were analyzed according to coastal typology (distinguishing between rocky and sandy coastal sectors) and distance from the shoreline (dividing distance values in concrete intervals). Rails were mostly emplaced in flat coastal areas due to the island’s rugged terrain: out of 1592 km of railway, ca. 350 km is located less than 1000 m from the shoreline (123 km on rocky sectors and 227 km on beaches and coastal plains). On sandy beaches and low sandy coastal sectors, approximately 6 km of track is within 25 m from the shoreline, a value rising to 16 km if a 50 m distance is considered, 48 km at 100 m and 103 km at 200 m distance. In correspondence of rocky platforms and high cliffed sectors, data reported for short distances between the rail and the shore are similar to ones observed along sandy coastal sectors, but differ when distance increases, i.e., there is only 32 and 47 km of railway respectively within 100 and 200 m from the shoreline. The emplacement of the railway embankment on beaches and dunes favored coastal squeeze and enhanced coastal erosion due to wave reflection on the embankment, which had to be protected by hard structures. Impacts on rocky sectors, with respect to beach and dune systems, are generally low because such sectors are usually stable (they do not need to be protected), less attractive to tourists and present small urban development. Tourism was affected by reducing landscape quality, beach access and width. More detailed studies and monitoring programs are necessary to locally assess the detailed impacts of the railway network, with this study constituting a preliminary but useful approximation to determine which coastal sectors are potentially the most affected. Results obtained in this paper can stimulate similar researches in other countries to prevent or decrease railway impacts on “Sun, Sea and Sand” tourism and, in general, on the coastal environment.

Estimating the marginal maintenance cost of different vehicle types on rail infrastructure

In this paper, we combine engineering and economic methods to estimate the relative maintenance cost of different types of damage on the Swedish rail infrastructure. The engineering method is good at predicting damage from traffic, while the economic method is suitable for establishing a relationship between damage and cost. We exploit the best features of both methods in a two-stage approach and demonstrate its applicability for rail infrastructure charging, based on a sample of 143 track sections comprising about 11,000 km of track. The paper implements for the first time the method previously proposed in Smith et al., whilst also enhancing the method in several respects. We demonstrate how the estimated relative maintenance costs related to different damage mechanisms can be used to calculate the marginal cost of different vehicle types. The results are relevant for infrastructure managers in Europe who wish to differentiate their track access charges such that each vehicle pays its short run-marginal damage cost, which can support more efficient use of the rail infrastructure and influence vehicle design to minimize system costs.

Monitoring and Modeling Railway Structures on High-Speed Lines with Asphalt Concrete Underlay: A Study on the Bretagne–Pays de la Loire Line

The design and durability of high-speed railway lines is a major challenge in the field of railway transportation. In France, 40 years of feedback on the field behavior of ballasted tracks led to improvements in the design rules. However, the settlement and wear of ballast, caused by dynamic stresses at high frequencies, remains a major problem on high-speed tracks leading to high maintenance costs. Studies have shown that this settlement is linked to the high acceleration produced in the ballast layer by high-speed trains traveling on the track, disrupting the granular assembly. The “Bretagne–Pays de la Loire” high-speed line (BPL HSL), with its varied subgrade conditions, represents the first large-scale application of asphalt concrete (GB) as the ballast sublayer. This line includes 77 km of conventional track with a granular sublayer of unbound granular material (UGM) and 105 km of track with an asphalt concrete sublayer under the ballast. During construction, instruments such as accelerometers, anchored deflection sensors, and strain gages, among others, were installed on four sections of the track. This paper examines the instrumentation as well as the acquisition system installed on the track. The data processing is explained first, followed by a presentation of the ViscoRail software, developed for modeling railway tracks. The bituminous section’s behavior and response is modeled using a multilayer dynamic response model, implemented in the ViscoRail software. A good match between experimental and calculated results is highlighted.

Vehicular tracks and the influence of land use and habitat protection in the British uplands

Uplands cover around 25% of the Earth's land surface and comprise highly sensitive soils and habitats of global ecological importance that together provision a suite of valuable ecosystem services. Access to upland areas for land management and recreation is increasingly dependent on the use of motorised vehicles. However, despite the widely acknowledged detrimental consequences of vehicle track development and use, this activity is not currently quantified or monitored.In this study, surfaced and unsurfaced vehicular tracks, footpaths and land cover in an approximately 5% sample of mainland British uplands (1910 km2) were mapped using aerial imagery dating between 2007 and 2016. An information theory approach was used to identify models that best predicted the presence and extent of surfaced tracks as a function of land cover, protected status, extent of blanket peat, proximity to human population and altitude.A total of 2104 km of track were recorded, with 27% defined as being surfaced. This equates to a mean (±SE) track density of 1.10 ± 0.15 km km−2 in current use by vehicles across upland Britain. Areas of managed heather and grass-dominated habitat were the primary predictors of the presence and extent of surfaced tracks and we found no evidence that areas of conservation interest with protective designation were less susceptible to track construction. These data indicate that wide-ranging vehicular track networks exist in ecologically sensitive environments across the British uplands, with implications for the integrity of sensitive habitats and soils. Land use and management activities that are not facilitating ecological improvement or conservation appear to be driving the presence of surfaced tracks in ‘protected’ areas. The findings suggest that: a) urgent review and revision of upland track legislation is required in Great Britain; and b) wider assessment of upland tracks should be undertaken to inform global conservation strategies for these environments.

Risk of increasing temperature due to climate change on high-speed rail network in Spain

With more than 3,200 km of track, the Spanish high-speed rail network is the longest network in Europe and the second largest in the world after China. Due to its geographical location in southern Europe, the entire network is exposed to periods of elevated temperatures that can cause disturbances and severe disruptions such as rail deformation, or in the worst case, lateral track buckling. In this study, the vulnerability of the current Spanish high-speed rail network is analysed in terms of track buckling failures with a Monte Carlo simulation. Downscaled temperature projections from a range of Global Climate Models (GCMs), under three Representative Concentration Pathways (RCP4.5, RCP6.0 and RCP8.5), were forced in a buckling model and particularized for different segments of the network. With that, the proposed methodology provides the number of rail buckles expected per year by assuming current maintenance standards and procedures. The result reveals significant increase in the occurrence of buckling events for future years, mainly in the central and southern areas of mainland Spain. However, relevant variations are found in different climates and time horizon scenarios in Spain. The anticipated buckling occurrences highlight the vulnerability of the Spanish rail network in the context of global warming scenarios. Overall, the proposed methodology is designed to be applicable in large-scale railway networks to identify potential buckling sites for the purpose of understanding and predicting their behaviour.

Preparing Track Geometry Data for Automated Maintenance Planning

Research on track quality behavior has been extensively published, and many different approaches have been presented to describe the process of track quality. The research goal of this paper is to form a basis for a data-driven tamping prediction based on track quality analyses over time. A research database containing asset information, executed maintenance tasks, and measuring data of some 4,400 km of track of the Austrian rail network in a time sequence of 16 years is available. The modified standard deviation of vertical track geometry is identified as an ideal track quality indicator for planning and predicting tamping tasks in Austria in the context of this research. Further analyses show that a linear regression function is best suited for describing track quality between two tamping tasks and shows the best accuracy for predicting track quality in the future. An algorithm was developed by means of the linear regression function that enables analyses of track quality behavior over time for long time series and the whole network. This includes track quality before and after tamping tasks as well as deterioration rates. In the future, these basics have to be combined with further technical evaluations to detect an optimal intervention limit. Furthermore, economical and operational considerations must be incorporated to find the optimal tamping strategy under the given conditions.

Classification and Analysis of Elements of Railway Infrastructure Maintenance in Order to Minimize Costs

Maintaining the railway infrastructure in a condition ensuring safe railway traffic is the basic responsibility of railway infrastructure managers resulting from the Rail Transport Act. Elements of the railway infrastructure are subject to difficult atmospheric conditions as well as changing dynamic loads resulting from the operation of a given part of the infrastructure. The lack of proper maintenance of tracks adversely affects their operation: lowering the permissible speed, reducing driving calm, decreasing the safety of railway traffic, increasing the degradation of aggregate and railway subgrade, as well as increasing the influence of dynamic impacts on the surrounding buildings. The following article presents an analysis of maintenance tasks performed at 5 different locations. For the purposes of the article, data were collected in 2016−2018 on 100 km of track from daily reports performed by qualified supervisors managing maintenance brigades. The aim of the article is to present the results of the collected data, to analyze the most common maintenance tasks, to determine the root causes that result in the need to perform specific tasks and to propose remedies. The aim of the research was to achieve market competitiveness by minimizing costs because today’s performance of duties related to the maintenance of railway infrastructure is characterized by very high costs associated with high workload, repair technology, the need to use specialized equipment, and temporarily exclude a part of the line from traffic. The research was carried out in a company which is a manager of railway infrastructure. Keywords: maintenance, railway infrastructure, railway infrastructure manager, costs

Establishing relationships between fuel economy and gear ratios of bus transmission units

The engineers of the GAZ Group developed the GAZ Vector Next 10 family of buses on the basis of the GAZon Next 10 truck. The parameters of the engine, transmission units and wheels of the new family of buses undergone significant changes, which inevitably affected their fuel economy. In this regard, the objectives of this work were formulated as the development of a methodology for determining the fuel economy of a bus and establishing relationships between these indicators and the gear ratios of transmission units. The base model of a family of buses designed for intercity passenger transportation was selected as the object of study. To assess the fuel economy of the bus, single indicators were selected: fuel consumption at given speeds and operating fuel consumption at operating speed. These indicators are determined by the graphs of the fuel and economic characteristics of the bus. The article sets out the methods for constructing the named graphs and determining the indicators of the fuel economy of the bus. The effect on the fuel consumption at given speeds of 60 and 80 km / h of gear ratios of the highest stage of five - and six-speed gearboxes and final drive with gear ratios of 3.9 and 4.55 is established. The gear ratios of the gearbox and final drive at which the bus consumes the largest and least amount of fuel per 100 km of track are determined. It is shown that a change in the gear ratios of the transmission units does not significantly affect the operational fuel consumption of the bus. The results of studies performed by the authors of the article can be used by the developer to optimize the gear ratios of the modernized GAZ family of buses Vector Next 10.