Origins and Current Status of the Different Communications-Based Train Control Products

2020 ◽  
Author(s):  
Kenneth Diemunsch ◽  
Nagaratnam Rabindran
Keyword(s):  
Traffic Control ◽  
Access Point ◽  
Current Status ◽  
Maintenance Cost ◽  
Signaling System ◽  
Large Cities ◽  
Signaling Systems ◽  
Train Control ◽  
Transit Agencies ◽  
Diagnostic Capabilities

Abstract Communications-Based Train Control (CBTC) technology is used by transit agencies in large cities to maximize the use of their infrastructure. In comparison with conventional block signal system and cab signaling system, CBTC provides the most efficient capabilities with respect to headway and throughput while being the most economical in terms of maintenance cost [1]. CBTC also provides better diagnostic capabilities compared to traditional signaling systems. It uses limited number of equipment on the trackside compared to traditional signaling systems and allows either a centralized architecture or distributed architecture. For these reasons, CBTC is now the favored system for new lines as well as most signaling system renewals.[1] Despite widely used CBTC standards, the signaling industry is not in agreement regarding what qualifies as a CBTC system and which projects are the first “real” CBTC projects. This work describes the different CBTC vendors, their genesis, when access point based radio was first introduced (access point based radio is also referred by signaling engineers as free space propagation radio), the different consolidations with other CBTC companies, and their major projects. From the authors’ viewpoint, it is appropriate to present the CBTC vendors by geographical areas, for instance in North America: Bombardier Transportation, Thales Rail Signaling Solutions, in Europe: Alstom Transport, Hitachi Rail, Siemens Mobility, in Asia: Beijing Traffic Control Technology, China Railway Signal and Communications, Mitsubishi Electric Corporation, and Nippon Signals.

Manage Successful Brownfield Applications

2018 ◽  
Author(s):  
Jian Sun ◽  
Kevin Blostic
Keyword(s):  
Mixed Mode ◽  
System Capacity ◽  
Signaling System ◽  
Maintenance Costs ◽  
Signaling Systems ◽  
Train Control ◽  
Operation And Maintenance ◽  
Track Circuit ◽  
Railroad Applications ◽  
New System

This paper provides a unique perspective on successful brownfield railroad applications. It presents realistic challenges and solutions when applying a turnkey solution with a replacement or an overlay system. Brownfield commissioning takes place when an existing infrastructure is to upgrade to a new system with a different technology than the incumbent one. As signaling systems are getting more and more complex, it is extremely important to maintain robustness in the system design as well as project execution, such as logistics, documentation, and issue reporting. Many transportation authorities are moving from their current train control signaling system to a new system to combat obsolescence issues, to gain better system capacity, and to lower operation and maintenance costs. This paper discusses brownfield commissioning in general, and also presents specific cases in migration from a track circuit interlocking system to a Communications Based Train Control (CBTC) system. These two systems have distinct characteristics that provide opportunities of coexistence, but also introduce difficulties in mixed-mode operations.

The Creation of Cab Signaling

2019 ◽  
Author(s):  
John Hofbauer
Keyword(s):  
The United States ◽  
Light Rail ◽  
Signaling System ◽  
Signaling Systems ◽  
Train Control ◽  
North East ◽  
The North ◽  
Rail Systems ◽  
The Us ◽  
Pennsylvania Railroad

Cab signaling enforces the separation between trains as well as enforcing trains to reduce speed as the train approaches signals displaying STOP. Cab signaling allow for and provides a safe way to eliminate the number of wayside automatic signals while the number of controlled speeds can be increased. Light Rail Transit (LRT) systems today are built completely with cab signaling and only fixed wayside signals are placed at interlockings for routing information. Experimental cab signaling systems began in the United States in the 1920s, kicked off by the Interstate Commerce Commission (ICC) ruling that required some form of Automatic Train Control (ATC) be installed on one passenger division by 1925. This paper will begin with examining the initial ATC designs (intermediate and continuous), the first experimental installations, the testing challenges and the overall enhancements that pioneered cab signaling systems in the US. The focus will include the teaming of the Pennsylvania Railroad with Union Switch and Signal (US&S) to develop, build and successfully test the continuous cab signaling system which later became the de facto standard. The early systems implemented used two (2) speeds, methods on adding a third speed and how the system became integrated with the existing automatic block signaling. How Pennsylvania Railroad (currently Amtrak) is still using the technology that started 100 years ago on the North East Corridor. It will also introduce how Light Rail systems operate on speed commands using cab codes.

Consequences of Failed Track Circuits on Conventional Signaling System in CBTC Projects

2013 ◽  
Author(s):  
Kenneth M. Diemunsch ◽  
Daniel J. Reitz
Keyword(s):  
Signaling System ◽  
Train Control ◽  
Backup System ◽  
Train Operation ◽  
Track Circuits ◽  
Track Circuit ◽  
Transit Agencies ◽  
The Relationship ◽  
Multiple Scenarios ◽  
Rapid Mass

In recent years, many rapid mass transit agencies have chosen Communication Based Train Control (CBTC) technology to refurbish their signaling system or to equip a new line. CBTC technology is a type of Automatic Train Control (ATC) that allows transit agencies to increase nominal throughput and to improve safety. The main functions of CBTC are described in [1.] and [2.]. This technology can operate without fixed wayside track detectors such as track circuits. However, track circuit equipment continues to be implemented on the tracks and in the equipment rooms. For authorities under the Federal Railroad Administration, current regulations require use of track circuit but the main functional reason is to have a backup system in case of CBTC failure. Most transit agencies decide to include track circuit occupied and vacant status into the CBTC system in order to enhance safety. How to enhance safety and keep train operation efficient during track circuit failure is a challenge for CBTC projects. This paper discusses the relationship between the CBTC and the conventional interlocking system when track circuit failure occurs. The analysis in this paper applies to both relay and solid state interlocking systems as both technologies have to deal with the same impact under this scenario. The method of detection of track circuit failure by the CBTC system and the possible restrictions on CBTC train operation are not presented. The paper focuses on the interface between the CBTC and the signaling system. It begins by introducing the different types of track circuit failures and their consequences on conventional signaling system to address and compare multiple scenarios. Then, the paper discusses how the CBTC system can affect the conventional signaling system equipment, such as signals and train stops, once it has detected a track circuit failure. Transit agencies’ different possible approaches to manage track circuits failures within the context of an operating CBTC system are explained.

The specificities of train control system at Moscow-Kazan-Yekaterinburg high-speed network

2017 ◽  
pp. 47-56
Author(s):  
Alexander Nikityn
Keyword(s):  
Control System ◽  
Collision Avoidance ◽  
Traffic Control ◽  
High Speed ◽  
Radio Channel ◽  
Signaling System ◽  
Train Control ◽  
Train Control System ◽  
High Speed Network ◽  
Computer Based

Objective: To consider the requirements for the train control system (SUDP) at “Moscow-Kazan-Yekaterinburg” high-speed network (VSM). To develop system-wide requirements for SUDP, including the selection of the structure and composition of subsystems. Methods: Computer-based interlocking with contactless control of vehicles should be applied at the stations as the main means for train traffic control. Vocal frequency track circuits were determined as the major means for free and busy status control of track at stations and blocks, an information channel giving an update of a track ahead, and the means for a rail integrity test. Stationary equipment for train collision avoidance via radio channel is to provide train traffic with speeds up to 400 km/h, multiple-aspect ALS-YEN (integrated continuous automatic cab signaling system), depending on control technology with speeds up to 250 km/h and ALS (automatic locomotive signaling system) – up to 160 km/h. Results: The issues of providing reliable and safe functioning of SUDP were considered, as well as liveness and interoperability. Practical importance: Control system realization in the suggested configuration with combined data communication via radio channel and conventional ALS and ALS-YEN facilities will make it possible to provide train traffic collision avoidance backup, as well as interoperability with high-speed transport lines. Keywords: High-speed network, train control system, centralized traffic control, computer- based interlocking, train traffic collision avoidance, radio-block center.

Evolutions in Railway Signaling: A “New Age” of Control?

2009 ◽  
Author(s):  
Cameron Fraser
Keyword(s):  
New Age ◽  
Safe Distance ◽  
Signaling Systems ◽  
Train Control ◽  
Train Routing

The development of railroad signaling systems evolved with the need to provide interlocking between points and signals, and block working to keep trains a safe distance apart. Accordingly, the archetypal behavior of train control is summed up as providing (1) safe and efficient train movement by (2) the management of train routing and separation. This has been rudimentary since the advent of railway signaling and propagated in even the most contemporary of technologies today.

scholarly journals Impact Analysis of Interference Sources on Data Communication System for CBTC Application

2012 ◽  
Vol 6-7 ◽  
pp. 356-360
Author(s):  
Shao Yin Wang ◽  
Yi Yu ◽  
Guo Xin Zheng ◽  
Qing Feng Ding
Keyword(s):  
Communication System ◽  
Impact Analysis ◽  
Data Communication ◽  
Access Point ◽  
Outdoor Environment ◽  
Test Bed ◽  
Communication Performance ◽  
Train Control ◽  
Data Throughput ◽  
Lab Test

We study the anti-interference performance of the 802.11 system when it works as Data Communication System (DCS) in Communication Based Train Control (CBTC). We first conduct extensive experiments on a 802.11b network to assess the ability on a lab test bed, then the outdoor experiments are also conducted. In the presence of jammer, we find that in each case of interference model, there exists a C/I threshold which determine the DCS-Access Point (DCS-AP) and DCS-Station Adapter (DCS-STA) communication performance. In the outdoor environment, different interference sources are adopted to investigate the data throughput value and other parameters of the DCS system under the critical state.

Communications-Based Train Control: Test Program Challenges

2018 ◽  
Author(s):  
Kenneth Diemunsch ◽  
Keith Altamirano
Keyword(s):  
Field Tests ◽  
Field Testing ◽  
Smooth Transition ◽  
Testing Time ◽  
Acceptance Test ◽  
Test Program ◽  
Root Cause ◽  
Train Control ◽  
Transit Agencies ◽  
Program Challenges

This paper discusses two real-world challenges faced by Communications-Based Train Control (CBTC) testing programs. a) Why is it that even after a successful complete system Factory Acceptance Test (FAT), the performance of the CBTC system during the first few months of field tests is prone to frequent failures? On some projects, it may be months between a successful FAT and the first operation in CBTC mode. b) How accurately and efficiently can the root cause of failures during the field tests be identified and how could a test program be improved to have a smooth transition from field testing to revenue service. Unlike commissioning a conventional signaling system, where after circuit break down and operation testing are completed, the system works well during revenue service, CBTC projects experience an additional round of ‘surprises’ when the system is put in service after months or years of testing [1]. This comment is valid for both new lines and signaling upgrade projects, it should be noted that signaling upgrade projects are more prone to ‘surprises’ due to the limited track access which reduces testing time. Even though the final test results prior to revenue service indicate no ‘showstoppers’, once system is placed in service, it is common to unearth major issues that impact sustainable revenue operation. Though, as it should, this often comes as a surprise to transit agencies installing CBTC for the first time, it is almost accepted as fate by most of the experienced CBTC engineers. This paper describes the tests performed prior to placing system in revenue service and analyzes some of the issues experienced. Detailed information regarding the field tests can be found in [2]. Description of possible mitigations used by CBTC suppliers and transit agencies are included, as well as likely reasons for such a predictable pattern on CBTC projects. Finally, ideas about how to continue improving the mitigation to minimize the risk of major system issues are presented.

Water in Cities

2005 ◽  
Author(s):  
Goh Kim Chuan ◽  
Avijit Gupta
Keyword(s):  
Water Supply ◽  
Southeast Asia ◽  
Distribution System ◽  
Significant Proportion ◽  
Water Shortage ◽  
Current Status ◽  
Annual Rainfall ◽  
Large Cities ◽  
Success Stories ◽  
Urban Settlements

Southeast Asia, with most of its area receiving an annual rainfall of more than 2000 mm, is a region of positive water balance. It is also an area where unfulfilled demand for water is not unknown. Such a contradiction happens at times in its towns and cities. Several Malaysian urban settlements, for example, suffer occasionally from water shortage in a country with an average annual rainfall of about 3000 mm. Kuala Lumpur went through a prolonged period of water shortage in 1998 (Hamirdin 1998) in spite of large allocations made earlier in various five-year plans towards developing water supply infrastructure. Such shortages are common during long dry periods associated with El Niño. Regional water shortages may become more common in future, especially with the rising population and economic expansion. The shortages are the result of an inability to meet the rising demand of water in cities driven by both increasing population and progressive prosperity. Serious shortage occurs in large cities such as Jakarta, Bangkok, and Manila where a significant proportion of their population has no immediate access to municipal potable water. Even where piped connection exists, supplies are not available round the clock and often do not meet the required water quality standards. In many cities the local sources are inadequate and water has to be brought in from rural areas. The demand for water in a city has to be met on both quantitative and qualitative terms. For example, drinking water supplied to households by a municipal administration has to meet a given standard (WHO 1993). Ideally a city should have enough water to drink, to meet industrial demand, and to be able to store an adequate volume under pressure for firefighting and street cleansing. Supplying a city with water requires water sources, a treatment system, a distribution system, and arrangements for treating waste water and its disposal. In this chapter we review the current status of water supply in urban Southeast Asia and the sources that are available, concentrating on the major cities. We indicate the success stories as well as the shortcomings.

Best Practices in Operating High Frequency Metro Services

2019 ◽  
Vol 2673 (9) ◽  
pp. 491-501 ◽  
Author(s):  
Shane Canavan ◽  
Alexander Barron ◽  
Judith Cohen ◽  
Daniel J. Graham ◽  
Richard J. Anderson
Keyword(s):  
High Frequency ◽  
Holistic Approach ◽  
Very High Frequency ◽  
Train Control ◽  
Rail Systems ◽  
Metro Systems ◽  
Increasing Demand ◽  
Total Capacity ◽  
Transit Agencies ◽  
Very High

Most metro rail systems worldwide are facing increasing demand and the need to deliver additional capacity in key corridors. Although total capacity reflects the combination of train capacity and frequency, increasing frequency is the primary strategy to increase capacity on existing lines where infrastructure is fixed. Higher frequencies also increase efficiency, by attracting more passengers and making existing journeys faster, thereby making better use of expensive rail infrastructure and increasing both metro revenues and wider economics benefits to the cities they serve. This paper is based on a study conducted for the Community of Metros, a worldwide group of metro systems, which surveyed 17 high frequency lines. The paper first documents the characteristics of high frequency lines [with 25 trains per hour (tph) or more defined as “high frequency” and 30 tph or more as “very high frequency”] and presents the various constraints to higher frequency operations, including how they interact and the various possible solutions. Five main categories of constraints were identified, relating to signaling and train control, station and train crowding, fleet, terminal turnarounds, and service complexity. To achieve the highest frequencies, it is essential for metro systems to take a holistic approach and identify not only the immediate constraints but also secondary and tertiary constraints that may prevent the full benefits of improvements from being realized. This paper provides guidance to those operating, funding, planning, and designing metro systems in how to maximize frequency and thereby deliver greater benefits to riders, transit agencies, and stakeholders.

scholarly journals Lessons from Photoreceptors: Turning Off G-Protein Signaling in Living Cells

Physiology ◽  
2010 ◽  
Vol 25 (2) ◽  
pp. 72-84 ◽  
Author(s):  
Marie E. Burns ◽  
Edward N. Pugh
Keyword(s):  
G Protein ◽  
Living Cells ◽  
G Protein Signaling ◽  
Protein Signaling ◽  
Signaling System ◽  
Signaling Systems ◽  
Recent Advances ◽  
Retinal Rods

Phototransduction in retinal rods is one of the most extensively studied G-protein signaling systems. In recent years, our understanding of the biochemical steps that regulate the deactivation of the rod's response to light has greatly improved. Here, we summarize recent advances and highlight some of the remaining puzzles in this model signaling system.

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