Mainline Railway Research Articles

Experimental bases for the rail track surface damage detection system

A diagnosis of rail surface is generally based on the classical method of direct assessment and track geometry measurements. Identification and qualification of inequality and damage on the surface rails is depend on the skills and experience person who conducting inspection. In times of increasing exploitation of railways, infrastructure managers decide to use systems supporting the assessment of technical condition of the railways. In order to improve efficiency of detecting and maintaining uniform assessment criteria developed systems for detecting and monitoring inequalities damage on the surface rails. This article presents the assumption being the basis of the experimental monitoring system dedicated to the Polish railway infrastructure manager. The foundation of the research will be measurement and analysis of the dynamic response of the selected railway vehicle. The functional requirements and the actual research methodology on selected section of the main railwayline have been discussed. The paper presents architecture of measurement subsystem installed on typical type passenger electric locomotive. The implementation of a method for assessing in existing monitoring system has been proposed.

Energy-Efficient Locomotive Operation for Chinese Mainline Railways by Fuzzy Predictive Control

With the increasing energy consumption in Chinese mainline railways amid the worldwide carbon emission concerns, the need for energy-efficient locomotive operation becomes urgent. Locomotive operation is directly linked to speed limits imposed by the train ahead through signaling. In China's mainline railways, speed limits for locomotive operation change frequently because of relatively short headways in a highly congested network. Whenever the speed limit changes, the locomotive operation must be determined again quickly to adapt to the new speed limit. As a result, the energy-efficient locomotive operation is a real-time optimization problem with time-varying constraints, in which the tradeoff between solution optimality and computational time is essential, but it has not been considered adequately in previous studies. This study develops a fuzzy predictive control approach, continuously providing locomotive operation instructions, with respect to the prevailing speed limits, to reduce energy consumption of train movement. The proposed approach is implemented in an onboard decision support system to assist drivers. The system is tested on the Ning'xi line in China. The results indicate that energy consumption on train operations is reduced by 4%, without increasing the runtime between stations, while the computational requirement satisfies the demand of real-time solutions. Extensive simulations show that the proposed approach is able to provide sufficient solution optimality in reasonable computational time under different operation settings.

Geomorphotechnical Map for Railway Mainline Infrastructure Improvement. A case study from Romania

Railway mainline improvement along critical sectors with high gradients and affected by natural hazards is a tough objective to be achieved by engineering projects. The present paper analyses a typical section of the Romanian railway network, where an old technical solution (within 8 km of rail there are eight curve sectors, 170-250 m in radius each and with gradients as high as 25-27‰.) limited the efficiency of rail traffic. The main cause for accident instances and increased maintenance costs over this section used to be line configuration but, recently, landslide occurrences definitely became a factor worth weighting upon in infrastructure planning as they are known to have interrupted the traffic for months. The geomorphotechnical map (focuses on engineering works as an indicator of major geomorphic limitations) was validated with the help of field data and the geotechnical diagram analysis. The objective is mapping and analysis of the relationship between railway infrastructure and morphodynamic features in order to obtain a map of a practical significance. Our study concludes by proposing new solutions for traffic improvement considering that this section will be a section of the Southern Branch of the IV-th Pan European Corridor, connecting Central Europe to Turkey and Greece.

Experimental assessment of the energy consumption of urban rail vehicles during stabling hours: Influence of ambient temperature

Urban rail has widely recognised potential to reduce congestion and air pollution in metropolitan areas, given its high capacity and environmental performance. Nevertheless, growing capacity demands and rising energy costs may call for significant energy efficiency improvements in such systems. Energy consumed by stabled rolling stock has been traditionally overlooked in the scientific literature in favour of analysing traction loads, which generally account for the largest share of this consumption. Thus, this paper presents the methodology and results of an experimental investigation that aimed to assess the energy use of stabled vehicles in the Tyne and Wear Metro system (UK). It is revealed that approximately 11% of the rolling stock's total energy consumption is due to the operation of on-board auxiliaries when stabled, and investigation of these loads is therefore a worthwhile exercise. Heating is responsible for the greatest portion of this energy, and an empirical correlation between ambient temperature and power drawn is given. This could prove useful for a preliminary evaluation of further energy saving measures in this area. Even though this investigation focused on a particular metro system in a relatively cold region, its methodology may also be valid for other urban and main line railways operating in different climate conditions.

‘And one fine morning -’: reflections on a double centenary

... the green light, the orgastic future that year by year recedes before us. It eluded us then, but that's no matter - tomorrow we will run faster, stretch out our arms farther... And one fine morning -So we beat on, boats against the current, borne back ceaselessly into the past.(The Great Gatsby, F. Scott Fitzgerald)In 2014, we have celebrated two momentous centenaries: that of the Royal Town Planning Institute (RTPI), and that of the University College London (UCL) Bartlett School of Planning - the UK's second planning department, coming hard on the heels of Liverpool in 1909 and the historic 1909 Housing, Town Planning, c the department a kind of glorified trade school. Michael Collins records that, as late as the mid-1920s, election to the TPI was based on 'merit'. Membership increased slowly from ninety-seven in 1914 to 438 in 1927; very few local authorities had the resources to secure the services of a professional town planner, had they desired to do so (Collins, 2014). The system was designed to 'be operated by local authorities with limited resources and little, if any, knowledge of town planning. This task was made difficult by the fact that regional and town planning were in their infancy, both as academic disciplines and fields of professional activity' (Collins, 2014). Planning did not play an important role in the government's approach to post-war reconstruction, which gave priority to the preparation of local authority housing schemes to meet a predicted national need for some 400,000 additional houses. Collins concludes that: 'the plan making system was tightly constrained, cumbersome and time-consuming. The issues that local authorities were expected to address were local, narrowly defined and subject to criticism' (Collins, 2014).At Liverpool and UCL, Adshead and Abercrombie both combined major profes- sional practices with part-time involvement in teaching and administration, as did their post-World War II successor, William Holford. Only in 1960, when Richard Llewelyn Davies was appointed first to the Bartlett Chair of Architecture and then in 1970 to the Chair of Planning, did research became at all significant. In his 1960 inaugural lecture, Llewelyn Davies argued that the architectural curriculum needed to be reshaped to incorporate a much wider range of essential knowledge, including 'the sciences which deal with the human being - both as an individual and as a member of a group' (Llewelyn Davies, 1960, 9; Hall, 2014b, 215). He concluded: 'The idea that these sciences are related to architecture is fairly new and we have still to work out how best to teach them. In doing so we shall be greatly helped by the development of research' (Llewelyn Davies, 1960, 10; Hall, 2014b, 217).The descent from the summitSoon after Llewelyn Davies took charge at UCL, the year after the Institute received its Royal Charter, planning in the UK reached some kind of apogee. By the late 1960s there was a national plan, regional strategic plans and a second generation of new towns, including Milton Keynes, Northampton and Peterborough. Every region had a Regional Economic Planning Council; the South East strategy proposed to link London to these new towns, and to other major developments at the edge of the region, by discontinuous growth corridors along main railway lines and the motorway network, then in mid-construction. …

Station Stopping of Freight Trains with Pneumatic Braking

In Chinese mainline railway, freight trains need to stop within passenger stations at times because of the delayed passenger trains. Without any decision-support system, it is very difficult for drivers to stop trains within stations with consistency in one braking action. The reasons are that braking performance of train changes with the conditions of braking equipment and the drivers’ subjective evaluations of track profiles and braking distance are vague and imprecise. This paper presents a fuzzy neural network (FNN), which is based on the historical datasets of train stops, to model the latest condition of train braking equipment and to attain the braking distance under a predefined braking rate, track profiles, and initial braking speed. The braking distance is used to find the initial braking position to advise the drivers on commencing braking action. Case studies confirm that it is feasible to stop trains within stations in one braking action by applying the proposed approach. Furthermore, the runtime and energy consumption of train movement are both reduced in comparison to the practical two-step action train stopping (TATS); that is, drivers stop trains before entering stations and remotor at a low speed before slowly stopping within stations.

Management of mine subsidence impact upon mainline railway infrastructure – the continued flirtation of underground mining with the brick arch culvert at Myrtle Creek, Tahmoor

Longwall mining within the Bulli Seam has been conducted beneath the Main Southern Railway (Sydney–Melbourne). The railway track subsided 0⋅6 m during Longwall LW25, and the same again during LW26 (though at a different location). While limited mining has been permitted previously under Main Railway Lines, for the first time longwall mining (LW25) has been conducted beneath a Main Line without constraint to the rail traffic and without constraint upon the mining. This paper presents the response of a 4⋅6 m diameter inverted horseshoe-shaped brick arch culvert, supporting the line, during the undermining by LW25 and subsequently by the retreat of LW26.

Future projections of temperature-related climate change impacts on the railway network of Great Britain

Great Britain’s main line railway network is known to experience various temperature-related impacts, e.g. track buckling and overhead power line sag at high ambient temperatures. Climate change could alter the frequency of occurrence of these impacts. We have therefore investigated the climate change impact on various temperature-related issues, identified during workshops with rail industry specialists, using a perturbed physics ensemble (PPE) of the Met Office’s regional climate model (RCM), HadRM3. We have developed novel approaches to combine RCM data with railway industry knowledge, typically by identifying key meteorological thresholds of interest and analysing exceedance of these out to the 2040s. We performed a statistical analysis of the projected changes for each issue, via bootstrapping of the unperturbed PPE member. Although neither the PPE nor the bootstrapping analysis samples the full range of uncertainty in the projections, they nonetheless provide complementary perspectives on the suitability of the projections for use in decision-making. Our main findings include projected increases in the summertime occurrence of temperature conditions associated with (i) track buckling, (ii) overhead power line sag, (iii) exposure of outdoor workers to heat stress, and (iv) heat-related delays to track maintenance; and (v) projected decreases in the wintertime occurrence of temperatures conditions associated with freight train failure owing to brake problems. For (i), the statistical significance varied with track condition and location; for (ii) and (iii), with location; and for (iv) and (v), projected changes were significant across Great Britain. As well as assessing the changes in climate-related hazard, information about the vulnerability of the network to past temperature-related incidents has been summarised. Combining the hazard and vulnerability elements will eventually support a climate risk assessment for the industry.

Influence of executive imperfections of railway steel bridges construction on operational capacity and fatigue capacity

In recent years, in our country are modernized and rebuilt several sections of railway lines, mainly main lines. The greater part is adapted to increased speeds. However, such an adaptation involve the reconstruction or construction of new bridges including steel ones. The paper concerns the executive imperfections of constructions of steel bridges which in recent years have been built in the modernized main railway lines. These imperfections consist of, among others, the geometric imperfections from the assumed construction project. This also applies to defects in welds of various types that occur in critical elements of bridge structure. The aim of this paper is to demonstrate the influence of imperfections on the load carrying capacity and fatigue of these structures. Author showed that the observed imperfections have a significant impact on the fatigue life - especially for weld defects, in the case of load carrying capacity their importance is much smaller. These analyses are performed by using the theoretical methods developed in previous reports. In the analysis new standards for the design of steel structures from Eurocodes group were used.

The method of the correlation and dispersion defining of the total power components in the electric transport devices

Purpose. Development and theoretical ground of the analytical method for the calculation of the active, reactive and total powers in the electric traction devices, taking into consideration the non-stationary character of the stochastic processes change of the voltage and current in the elements of these systems. Methodology. The mathematical methods of the random processes theory and the “discrete electrical engineering” methods are used for solving the main problem of this paper. Findings. The Method of the Correlation and Dispersion is developed for definition of the active power, the reactive power by Fryse and the total power of the devices in the elements of the electric traction system of the main-line railways. The method is based on the well-known concepts of auto- and inter-correlation functions of the random processes which govern the feeder voltages and the currents in the traction power supply subsystem as well as the currents and voltages of the electric rolling stock. The method developed in this paper allows estimating the powers of both stationary and non-stationary processes. This method can be used for the analysis of both the traction mode and the regenerative braking mode of the electric rolling stock. The total power components were calculated for the one of the feeder areas of the Prydniprovsk railway using this method. The results show the significant flow of the reactive power in the traction power supply system. This fact is also confirmed by the high values of the reactive power coefficient. Originality. Scientific novelty of the research is consisted in the following. Firstly, for defining the active and reactive powers in elements of the traction power supply system the new method (the Method of Correlation and Dispersion) is created and grounded. This method is different from other existing methods because it takes into consideration the varying non-stationary character of the chance processes of the feeder and substation voltages and currents. Secondly, in the DC traction power supply system the large values of the exchange reactive power by Fryze were created for the first time. Practical value.The method and its technique allow calculating the main energy coefficients for the traction power systems such are the reactive power coefficient, the main and additional active power losses in the power circuit of the electric rolling stockand the traction power supply system.

Numerical modelling of shallow abandoned mine working subsidence affecting transport infrastructure

This work presents details of a shallow mining subsidence event that occurred in the summer of 2001 causing the formation of crown-holes at the surface which affected the East Coast Main Railway line in the UK. This subsidence event caused significant disruption and the remediation effort required the construction of a 1.8km long diversion built on a piled, reinforced concrete raft. Details of the ground investigation are summarised along with a large parametric numerical modelling study undertaken in FLAC 3D into the potential causes of the instability, including the role of variations of the level of the groundwater table, the influence of the structure of the rock mass and also the potential geometry of the abandoned workings. Ultimately the modelling allowed constraints to be placed on the likely excavation width of the workings at the site along with bedding spacing and strength of the overlying rock mass. The modelling also suggests that the increase in the ground water table may also have been a factor in the occurrence of instability on the site.

저상 및 고상 철도 승강장 겸용 승강문 스텝 개념설계

일반 간선열차에서 주로 사용하는 저상승강장과 수도권 전동차에서 주로 사용하는 고상승강장을 동시에 안전운행하기 위한 니즈기술로서, 저상/고상 승강장에 상관없이 승하차할 수 있는 철도차량 승강문 스텝장치가 필요하다. 본 연구에서는 이를 대비하여 저상/고상 승강장 겸용 승강문 스탭의 기능 및 제작 요구사항을 검토하였다. 세밀히 검토한 결과, 합리적 설계안은 자체 언더프레임의 손상 및 철도승강장의 이격거리 변동성을 최소화 할 수 있는 텔레스코픽 슬라이딩 스텝방식이라고 판단된다. 또한 다양한 요구조건을 고려하여 각 단계별 스텝 동작 과정 및 제어 흐름도를 제시하였다. In order to operate trains both mainline railroad platform and metropolitan subway line platform, it is necessary to develop the doorstep equipment of the rolling stock regardless of low(500mm, mainline) and high level platforms(1,135mm, metropolitan subway line) because of the requisite door safety system. In this study, two different types of platforms were examined. On closer examination, it seems that the conceptual design is suitable for telescopic sliding type doorstep equipment to minimize damage to the carbody underframe of railway vehicles and can also minimize the variation of the distance between the railway platform. Furthermore, the operation process and control flowchart of doorstep equipments by stages are proposed by various performance requirements.

철도차량의 저상 및 고상 승강장 겸용 승강문 스텝에 대한 내구성 평가

국내 여객을 취급하는 철도역사의 승강장은 간선철도노선의 저상승강장(500mm)과 광역전철구간의 고상승강장(1135mm)으로 구분 운용되고 있다. 저상승강장 전용 중 고속 열차가 수도권 전철구간(고상승강장)과 본선구간(저상승강장)에서 혼용 운영될 경우를 대비하고 안전운전 및 승객편의를 함께 고려하기 위해 저상 고상 승강장 겸용 승강시스템의 개발은 필수적이다. 한편 현재 개발 중인 시스템(스텝)에 대한 국내의 내구성 및 신뢰성 시험 기준은 존재하지 않는다. 따라서 본 연구에서는 저상/고상 승강장 겸용 텔레스코픽 슬라이드방식 승강문 스텝의 개발을 위한 연구 일환으로서, VPD관점에서 내구성 해석을 수행하고 신뢰성 보증시험에 준한 무고장 시험시간동안 실물 리그시험을 통하여 이의 내구성 기준 및 보증수명을 검토하였다. The platform of railroad station for domestic passenger train has been operated at two categories like the platforms if low level(500mm, mainline) and high level(1,135mm, metropolitan subway line). To operate both metropolitan subway line and mainline railroad safely, it is essential to develop the doorstep equipment of railway vehicle regardless of low and high level platforms. On the other hand, the domestic test standard at durability and reliability of doorstep equipment has not been existed until now. This study aims at the development on doorstep equipment of telescopic sliding type for low and high level platforms. Durability analysis with VPD(Virtual Product Development) techniques are performed and the durability standard & qualification life through the rig test during no failure test time is examined in accordance with reliability qualification test.

Feasibility of discontinuous electrification on the Great Western Main Line determined by train simulation

The UK has a number of main line railway routes that are not yet electrified. Some of these routes are under active consideration for electrification and the UK Government has recently announced the electrification of the Great Western Main Line (GWML). Railway electrification requires a large capital investment in infrastructure. Areas with limited clearance, such as tunnels and sections through overbridges, are particularly expensive to electrify. In this paper, train performance on the GWML, from London Paddington to Cardiff and vice versa, is modelled for three cases: no electrification; full electrification; and electrification that does not include tunnels, most notably the Severn Tunnel. The modelled trains were: the High Speed Train hauled by pairs of Class 43 diesel-electric locomotives; the nine-car Class 390; and Intercity Express Programme (IEP) trains formed as straight electric or bi-mode multiple units. Bi-mode trains combine electric and diesel traction in the same train. The considered IEP trains included both five-car and eight-car bi-mode options. Journey time, energy consumption and CO2 emissions were determined in each case. Electrification of the route will result in a reduction in energy consumption, carbon emissions and journey time, with the longest trains offering the greatest benefit. Under normal conditions, all modelled trains were able to complete the journey under discontinuous electrification. However, a small reduction in entry speed into the Severn Tunnel resulted in stalling of the exclusively electric trains. Bi-mode rail vehicles completed the journey in all cases and, as to be expected, also when tunnel entry speed is reduced; journey time, energy consumption and carbon emissions are not majorly impacted compared to exclusively electric operation.

철도차량 슬라이드식(텔레스코픽) 승강문 스텝의 강도평가

국내 여객열차 전용 승강장은 높이에 따라 두 가지 종류로서, 일반 간선열차에서 주로 사용하는 저상 승강장과 수도권 전동차에서 주로 사용하는 고상승강장으로 구분된다. 중 고속 열차가 수도권 전철구간과 본 선구간에서 혼용할 경우에 안전운전 및 승객편의를 함께 고려하기 위해서는 저상/고상 승강장에 상관없이 승하차할 수 있는 승강문 스텝장치가 필요하다. 본 연구에서는 전철역사 및 일반 철도역사에서 모두 승하차가 가능한 저상/고상 승강장 겸용 승강문 스텝 개념설계(안)의 구조해석 및 강도시험을 수행하고 이의 안전성을 검토하였다. Heights of a platform above the rail for the passenger train in the country are classified into two categories such as the low level (500mm; mainline) and the high level (1,135mm; metropolitan subway line) platforms. In order to operate similarly both a mainline railroad and a metropolitan subway line, as the requisite door safety system, it is necessary to develop the doorstep equipment of the rolling stock regardless of both the low and high level platforms. In this study, Structural analysis and mechanical strength test of doorstep equipments used for two types of platforms are performed on the supposition that the train only for the low level platform could stop in the both low and high level platforms.

영주지역 압쇄암의 공학적 특성 연구

본 연구의 대상지역은 영주댐 건설로 인해 이설되는 중앙선 철도 건설 예정지로 수 km에 걸쳐 연성전단작용에 의한 습곡과 압쇄암이 분포한다. 연성전단대는 지질시대 동안 작용한 단층작용으로 변형되어 복잡한 지질구조를 보인다. 연성전단대는 고온고압의 지하십부(>8km)에서 작용한 변형에 의한 광물의 재결정 작용으로 엽편상의 유동조직을 가지는 압쇄암이 발달하며, 이로 인해 지표부근(<2km)의 변형으로 형성된 단층대와 구별되는 공학적 특성을 가진다. 압쇄암의 특성을 파악하기 위해 시편으로 제작된 암석을 대상으로 변형률과 변형에 수반된 압축구조의 모양을 분석하였다. 단층대의 변형된 모양은 엽리상의 편원(oblate)한 모양이 우세한 반면 압쇄대는 광물의 신장에 의한 편장(prolate)한 형태가 우세하다. 변형률은 변형이전 상태를 기준으로 단층대가 1.2배미만의 변형을 보이는 것에 비해 압쇄대는 최대 2.5배의 변형을 나타내는 것으로 분석되었다. 불연속면을 기준으로 적용한 암반분류에서 경암의 일축압축강도는 연암정도의 강도를 보였으며, 일정 시간 수침 후에 강도의 변화가 관찰 되었다. 본 연구결과 조사된 암석들의 공학적 특성은 광물조성과 화학 조성에 기초한 풍화저항력이 비교적 높은 것을 고려할 때 압쇄작용에 수반된 미세균열구조에 의한 것으로 판단되었다. 따라서 압쇄암이 넓게 분포하는 지역에서 터널굴착을 하는 경우, 미세균열에 의한 팽창과 지하수 유입에 의한 강도저하가 발생할 수 있으므로 시공시 각별한 주의가 필요한 것으로 판단되었다. The area to be studied is the place where the main line rail way will be constructed in accordance with the scheduled construction project of Yeongju dam, and is a fold and mylonite zone over several km that is formed by ductile-shearing effect. The ductile shear zone, which has been transformed by faulting for long geological time, shows a complicated geological structure. Due to the recrystallization of mineral caused by transformation in deep underground (>8km), a mylonite zone with lamellar structure has properties distinguished from other fault zones formed by transformation near earth surface <2km). To see the properties of mylonite, this study analyzed the transformation rate of sample rocks and the shape of constriction structure accompanied with transformation. While the transformation of fault zone shows a round oblate, the mylonite zone shows a prolate form. Transformation rate in fault zone was measured to be less than 1.2 compared to the state before transformation while the measured rate in mylonite zone was 2.5 at most. Setting the surface of discontinuity as the base, the unconfined compressive strength of slickenside can be categorized in sedimentary rocks, and a change of strength was observed after water soaking over certain time. Taking into account that the weathering resistance of the rock based on mineral and chemical organization is relatively higher, its engineering properties seems to result from the shattered crack structure by crushing effect. When undertaking tunnel construction in mylonite zone, there should be a special care for the expansion of shattered cracks or the fall of strength by influx of ground water.

철도에서의 물류공동화 적용 방안에 관한 연구

물류공동화는 운송부분에서의 공동화로 시작되어 최근에는 배송과 보관 등 물류의 전 분야에서 도입되고 있으며, 물류공동화에 의한 효율성은 여러 형태로 입증되고 있어 많은 부분에서 물류공동화를 적극적으로 도입하고 있다. 그러나 현재 추진 또는 시행되고 있는 물류공동화는 도로를 중심으로 공동간선수송, 공동배송, 공동보관 등이 시행되고 있는 실정이다. 또한 국가주도의 물류단지에서의 공동화와 민간부분에서의 공동화가 활발히 시행되고 있는 실정이다. 이에 본 논문에서는 환경 친화적인 수송수단으로 부각되고 있는 철도부분에서의 물류공동화 도입방안에 대하여 검토하였다. 기존 철도분야에서의 물류공동화 사례 분석 등을 시행하고, 향후 철도에서 물류공동화 도입이 가능한 분야들 중 간선수송에서의 공동화뿐만 아니라 철도역에서의 보관, 배송부문에서의 물류공동화 도입 방안 등에 대하여 검토를 시행하고 도입방안을 제시하였다. The logistics collaboration is begun in the transport part and introducing it in all fields of the distribution including delivery and the storage in these days. The effectiveness by the logistics collaboration is proved in many forms and adopted in many parts positively. However, logistics collaboration are enforced around road transport now. In this paper, it is examined for logistics collaboration introduction plan in the railroad part which is outstanding in environmental. The logistics collaboration are examined for transport and storage in not only the Railway main line transport but also the railroad station.

Real-Time Database System Implementation of Railway Signal Power Source Remote Monitoring

Railway signal is a key technology for high-speed railway，which is the foundation to keep the high-speed train line. Railway signal power is the automatic blocking of railway lines and 10kV lines transform into 380V power through after the power supply for railway signals. Signal power as the railway traffic signal of the power supply, it belongs to the first level of power system load. Its 10kV high voltage side stik up by the major of electric, 380V low voltage side maintenance by the signal major. When the signal power failure, often occur shirk responsibilities between the different majors, in order to define the responsibilities of the accident better, which need automation remote monitoring for main railway lines of the railway signal power and scheduling control as soon as possible[1-3].

철도 고속화에 따른 단계별 신호시스템 구축방안 연구

Studies suggested an increase in the competitiveness and roles of mainline railways like speed and accessibility improvement, as a fundamental direction of the National Transport Network Plan. At this point, topics presented especially for strengthening the role of human and environment centered transportation: as to the greatly improved speed competitiveness, there are an operational speed above 180㎞/h ∼ 200㎞/h and traveling within 2 ∼ 3 hours among big cities. As to accessibility improvement, there are accessibility to main railway stations within 30 minutes, and the improvement of accessibility, safety, eco-friendliness, amenity etc. As a part of these suggestions, field specific plans were proposed for the establishment of expressed mainline railway network in Korea such as train’s, civil structures, trolley lines etc. In this paper we analyzed the conventional lines and systems to figure out whether to change details in terms of H/W of signaling system. Additionally, we reviewed the compatibility or difference of signalling system depending on train’s speed. With this result, we deduced the number of virtual blocks specific to the speed of 180㎞/h, 200㎞/h and 230㎞/h, which were showed for the speed improvement considering each variable like blocks, braking distance etc. In this way, we suggested the railway signal system establishment plan considering safety operation.

Superstructure Stabilization of Ballast Bedded Railway Tracks with Geogrids

The paper deals with the research and development of the authors related to investigation of geogrid railway ballast reinforcement. It summarizes the theory of the geometrical deterioration of railway tracks, as well as the advantages of the use of geogrid reinforced ballast in railway superstructure. This article summarizes the results of the field tests with five different geogrid types on a Hungarian main railway line and laboratory multi-level shear box tests. It points out to future research possibilities, for example the modelling of laboratory multi-level shear box tests with discrete element method that may certify their results.