scholarly journals Alternate Double Single Track Lines

2016 ◽  
Author(s):  
Zacarias Grande Andrade ◽  
Paola Moraga Contreras ◽  
Enrique Castillo Ron
Keyword(s):  
Travel Time ◽  
High Speed ◽  
Time Increase ◽  
Single Track ◽  
Maintenance Costs ◽  
Railway Infrastructure ◽  
Double Track

The paper discusses the advantages and shortcomings of alternate double single track (ADST) lines with respect to double track lines for high speed lines. ADST lines consists of sequences of double and single track segments optimally selected in order to reduce the construction and maintenance costs of railway lines and to optimize the timetables used to satisfy a given demand. The single tracks are selected to coincide with expensive segments (tunnels and viaducts) and the double tracks are chosen to coincide with flat areas and only where they are necessary. At the same time, departure times are adjusted for trains to cross at the cheap double track segments. This alternative can be used for new lines and also for existing conventional lines where some new tracks are to be constructed to reduce travel time (increase speed). The ADST proposal is illustrated with some examples of both types (new lines and where conventional lines exist), including the Palencia-Santander, the Santiago-Valparaíso-Viña del Mar and the Dublin-Belfast lines, where very important reductions (90 %) are obtained, especially where a railway infrastructure already exist.DOI: http://dx.doi.org/10.4995/CIT2016.2016.3426

scholarly journals Identification of Precast Parapet Work Activities in Elevated Railway Construction

2021 ◽  
Vol 2 (02) ◽  
pp. 52-61
Author(s):  
Pungky Dharma Saputra
Keyword(s):  
High Speed ◽  
Descriptive Analysis ◽  
Light Rail ◽  
Infrastructure Development ◽  
High Speed Rail ◽  
Work Activities ◽  
Railway Construction ◽  
Railway Infrastructure ◽  
Concrete Casting ◽  
Double Track

Railway infrastructure development is very massive in Indonesia. Many projects have been constructing since 2013, such as the Mass Rapid Transit (MRT), Light Rail Transit (LRT), Double-Double Track (DDT), and High-Speed Rail (HSR). And all of these projects were design with elevated structures. When applying precast parapet panel technology in the MRT project elevated section, the contractor didn’t have a reference for precast parapet work activities. Hence, it required new planning for its construction and took time. The project sample of this research was MRT Jakarta CP 103 Project. There were three stages in this research starting from documentation analysis, expert judgment, and respondent survey. There were 5 bridge construction experts and 30 respondents which were professional engineers asked for their recommendations and opinions. Descriptive analysis was applied to know the percentage of opinions. This research focuses on identifying precast parapet activities in elevated railway construction project. There are 14 activities that had been identified in this research, namely preparation, position survey, adjustment material installation, precast parapet panel shifting from trailer to the top of deck slab, precast parapet panel distribution, precast parapet panel installation, rebar parapet installation for concrete stitch, sealing work, concrete casting, formwork dismantling, and finishing. These activities will be very useful for similar precast parapet works in a future project.

scholarly journals Estimation of conditions of using combined single-track and double-track railways at high-speed traffic

2018 ◽  
Vol 216 ◽  
pp. 02010 ◽  
Author(s):  
Alexei Dmitrenko ◽  
Sergei Karasev ◽  
Alexandra Kalidova ◽  
Dmitry Sivitsky
Keyword(s):  
Simulation Modeling ◽  
High Speed ◽  
Capital Investments ◽  
Single Track ◽  
Railway Transportation ◽  
Relevant Issue ◽  
Important Condition ◽  
High Speed Railway ◽  
Double Track ◽  
Track Line

An important condition when arranging high-speed railway transportation with insignificant traffic is saving of capital investments in construction of new lines or the reconstruction the existing ones. Development of methods for multi-criteria estimation of the possibility of using fully single-track blocks on a line with high-speed traffic, as well as single-track blocks with double-track inserts, is a relevant issue. The purpose of the study is to develop the criteria and the method for estimation of the feasibility of using single-track elements on a line with high-speed traffic. Methods of simulation modeling, mathematical statistics, regression analysis were used. A method that includes estimation of the technological conditions of using single-track elements on a line with high-speed traffic instead of double-track blocks was developed. The method can be used for multi-criteria optimization of the configuration of a combined single-track and a double-track line using single-track elements in high-cost areas.

scholarly journals Justification of a rational option of development of the highspeed railway according to technical, technological and economic criteria

2021 ◽  
pp. 129-135
Author(s):  
Anna Leonidovna Kravets ◽  
Arkadii Valerievich Chernolutskyi ◽  
Svyatoslav Vitalievich Serpokrylov
Keyword(s):  
Travel Time ◽  
Capital Investment ◽  
High Speed ◽  
Systemic Effect ◽  
Single Track ◽  
High Speed Railway ◽  
Passenger Traffic ◽  
First Case ◽  
Distribution Of Resources ◽  
Economic Criteria

When a new high-speed railway is designed on the routes with the existing mixed(freight and passenger) traffic, part of the trains can be relocated from the existing railway to thenew one. This will have an additional effect of the increasing current capacity of the existing railway. A method is proposed for justification of a rational option for the development of a high-speedrail on the basis of technical, technological and economic criteria. It is proposed to solve the problemof determining the rational option for the development of a high-speed railway as the problem ofoptimal distribution of resources among the components of the railway, taking into account technical,technological and economic criteria. The result is a set of solutions consisting of options for thedevelopment of each component of the railway, which will provide the maximum systemic effect forthe railway as a whole. Each jth option of the development of the ith component of a high-speed railwaycan be described by three main indicators: the travel time of a high-speed train; capital investmentsrequired to implement this option; and the available traffic capacity of the component. Depending onthe problem being solved, each of the listed parameters can act both as a criterion and as a limitation.Depending on the purposes of the design, it is proposed to consider the problem of determiningthe rational option for the railway development either in the direct or inverse setting. In the first case,the systemic effect is expressed by an objective function that minimizes the amount of necessarycapital investments in the railway infrastructure while ensuring the stipulated travel time of a highspeed train. In the second case, the purpose is to minimize the travel time of the train withoutexceeding the specified amount of capital investment in the development of all components of therailway.The results obtained can be used to justify decisions on the use of single-track components andto determine the rational configuration of single-track lines when high-speed traffic is organized.

scholarly journals Auxiliary Stopping Area Layout Method for High-Speed Maglev Operated Bidirectionally on Single Track

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yi Yu ◽  
Pengzi Chu ◽  
Danyang Dong ◽  
Xi Jiang ◽  
Huahua Zhao ◽  
...  
Keyword(s):  
High Speed ◽  
Construction Cost ◽  
Demand Characteristic ◽  
Single Track ◽  
Layout Problem ◽  
Layout Algorithm ◽  
Operation Efficiency ◽  
Safety Operation ◽  
Train Safety ◽  
Double Track

Auxiliary stopping area (ASA) is the necessary emergency facility for train safety of the normal high-speed maglev. The study addresses the ASA layout problem of the high-speed maglev operated bidirectionally on single track. First, an optimization model of the ASA layout for unidirectional double-track lines considering train safety, operation efficiency, and construction cost is established, and two basic methods of the ASA layout are investigated based on the distance demand characteristic of ASAs. Then, the ASA layout problem of bidirectional single-track lines is analyzed, and an ASA two-way coordination layout algorithm (ASA-TWCLA) is proposed. Finally, a numerical experiment is carried out. The results suggest that under the premise of train safety and operation efficiency, compared with using the basic methods separately on the two directions, adopting the ASA-TWCLA algorithm can obtain a more economical ASA layout scheme for the same scenario.

Saskatchewan Highways and Transportation Reduced Tire Pressure Initiative

1997 ◽  
Vol 1589 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Thomas L. Davies ◽  
Tami F. Wall ◽  
Allan Carpentier
Keyword(s):  
High Speed ◽  
Membrane Surface ◽  
Vehicle Stability ◽  
Road Maintenance ◽  
Long Term Effects ◽  
Tire Pressure ◽  
Reduced Pressure ◽  
Maintenance Costs ◽  
Short And Long Term

After examination of the research carried out by other agencies, Saskatchewan Highways and Transportation (SHT) embarked on an initiative to adapt low tire pressure technologies to the province's needs and environment. The focus of the initiative was to explore several technical questions from SHT's perspective: (a) Can low tire pressures be used to increase truck weights from secondary to primary without increasing road maintenance costs on thin membrane surface roads? (b) What are the short- and long-term effects of tire heating under high-speed/high-deflection constant reduced pressure (CRP) operations in a Saskatchewan environment? (c) What effects do lower tire pressures have on vehicle stability at highway speeds? To date, significant opportunities have been noted on local hauls (less than 30 min loaded at highway speeds) for CRP operation and long primary highway hauls that begin or end in relatively short secondary highway sections that limit vehicle weight allowed for the whole trip for central tire inflation technology. The background and environment for the initiative and the investigations and demonstrations envisioned and undertaken are briefly outlined.

scholarly journals Process characterization and analysis of ceramic powder bed fusion

2021 ◽  
Author(s):  
Kevin Florio ◽  
Dario Puccio ◽  
Giorgio Viganò ◽  
Stefan Pfeiffer ◽  
Fabrizio Verga ◽  
...  
Keyword(s):  
High Speed ◽  
Ceramic Powder ◽  
Integrating Sphere ◽  
Alumina Powder ◽  
Powder Bed Fusion ◽  
Single Track ◽  
Ceramic Powders ◽  
Pure Alumina ◽  
Powder Bed ◽  
Melt Pool

AbstractPowder bed fusion (PBF) of ceramics is often limited because of the low absorptance of ceramic powders and lack of process understanding. These challenges have been addressed through a co-development of customized ceramic powders and laser process capabilities. The starting powder is made of a mix of pure alumina powder and alumina granules, to which a metal oxide dopant is added to increase absorptance. The performance of different granules and process parameters depends on a large number of influencing factors. In this study, two methods for characterizing and analyzing the PBF process are presented and used to assess which dopant is the most suitable for the process. The first method allows one to analyze the absorptance of the laser during the melting of a single track using an integrating sphere. The second one relies on in-situ video imaging using a high-speed camera and an external laser illumination. The absorption behavior of the laser power during the melting of both single tracks and full layers is proven to be a non-linear and extremely dynamic process. While for a single track, the manganese oxide doped powder delivers higher and more stable absorptance. When a full layer is analyzed, iron oxide-doped powder is leading to higher absorptance and a larger melt pool. Both dopants allow the generation of a stable melt-pool, which would be impossible with granules made of pure alumina. In addition, the present study sheds light on several phenomena related to powder and melt-pool dynamics, such as the change of melt-pool shape and dimension over time and powder denudation effects.

scholarly journals The Impacts of High-Speed Rail on Regional Accessibility and Spatial Development—Updated Evidence from China’s Mid-Yangtze River City-Cluster Region

2021 ◽  
Vol 13 (8) ◽  
pp. 4227
Author(s):  
Liwen Liu ◽  
Ming Zhang
Keyword(s):  
Travel Time ◽  
Yangtze River ◽  
High Speed ◽  
Spatial Development ◽  
Spatial Inequality ◽  
County Level ◽  
High Speed Rail ◽  
Cluster Region ◽  
River City ◽  
City Cluster

There has been long and ongoing interest in the impacts of high-speed rail (HSR) on regional spatial development. Most existing studies, however, reported findings at relatively coarse geographic scales, i.e., at the prefecture-city or above level in the Chinese context. This paper presents the empirical evidence of HSR impacts from the county-level cities in China’s Mid-Yangtze River City-Cluster Region (MYRCCR). The study utilized rail time data and the socio-economic data for MYRCCR’s 185 county-level cities in the years of 2006 (without HSR) and 2014 (with HSR) and analyzed the impacts of HSR on inter-city travel times, accessibility, spatial inequality, and regional economic linkages among the MYRCCR cities. The results show that, from 2006 to 2014, HSR reduced city-to-city average travel time by 34.5% or 124 min and improved accessibility to all cities in the MYRCCR. HSR’s impacts on accessibility and spatial equality exhibited a scale-differentiated pattern. MYRCCR-wide, HSR transformed a pattern of spatial polarization towards the one of corridorization. Cities located on major HSR corridors became more balanced in 2014 than in 2006. Nevertheless, at the county-city level, the gap between cities with the most and the least accessibility gains was much greater than the gap between those with the largest and the smallest travel time savings. Attributable to HSR services, the intensity of economic linkage increased between MYRCCR cities, especially between the provincial capital cities and those on the major lines of the national HSR grid, which implies an emerging process towards territorial cohesion in MYRCCR. National, provincial, and local governments should consider transportation as well as non-transportation policies and measures to direct HSR impacts towards further enhanced spatial development and regional equality.

Inter-city transport infrastructure and intra-city housing markets: Estimating the redistribution effect of high-speed rail in Shenzhen, China

Urban Studies ◽  
2021 ◽  
pp. 004209802110178 ◽  
Author(s):  
Zheng Chang ◽  
Mi Diao
Keyword(s):  
Travel Time ◽  
High Speed ◽  
Local Effect ◽  
Transport Infrastructure ◽  
Network Effect ◽  
Housing Values ◽  
High Speed Rail ◽  
The City ◽  
Redistribution Effect ◽  
Metro Network

This study analyses the changes in intra-city housing values in response to improved inter-city connection brought by high-speed rail (HSR), using the opening of the Hangzhou–Fuzhou–Shenzhen Passenger Dedicated Line (HFSL) in Shenzhen, China, as an example. The opening of the HFSL and its integration into the local metro network at Shenzhen North Station provide exogenous intra-city variations in access to the surrounding economic mass. With a difference-in-differences approach, we find that the HFSL showed a negative local effect as housing values declined by 11.5%–13.3% in the proximity of Shenzhen North Station relative to areas further from the station after the opening, possibly due to the negative externalities of the HFSL. The HFSL effect can spread along the metro network and lead to, on average, a 7% appreciation of housing values around metro stations (network effect). The direction and strength of the network effect vary by metro travel time between Shenzhen North Station and metro stations. Housing values decreased by 7.7% around metro stations within 5–15 minutes of metro travel time but increased by 63.6%, 16.6% and 29.2% around metro stations within 15–25, 25–35 and 35–45 minutes of metro travel time to Shenzhen North Station, respectively. The HFSL effect on housing values diminishes when the rail travel time is above 45 minutes. We interpret these findings as evidence of the redistribution effect in the city related to HSR connection.

Current Design Activities on British Railways

1969 ◽  
Vol 184 (4) ◽  
pp. 5-14
Author(s):  
J. F. Thring
Keyword(s):  
High Speed ◽  
Design Review ◽  
New Developments ◽  
Maintenance Costs ◽  
Current Design ◽  
Design Activities ◽  
Selection Of ◽  
Freight Vehicles

With the identification of profitable freight areas and the selection of growth traffics for development has come the need to review in detail the running gear and, in particular, the suspensions of both 4-wheeled and bogie vehicles. This design review has been aimed at ensuring a high-speed capability for all new freight vehicles coupled with safety at all times, low maintenance costs, and maximum availability. After reviewing traditional suspensions, in wide use, with reference to their known strengths and weaknesses, the paper discusses in some detail the philosophy now being applied in B.R. design offices to new freight running gear, for both 4-wheeled and bogie vehicles, to ensure satisfactory achievement of technical objectives. Examples of new developments are provided, together with comments on progress to date.

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