Prevention of End-of-Track Collisions at Passenger Terminals via Positive Train Control

2019 ◽  
Vol 2673 (9) ◽  
pp. 471-479
Author(s):  
Zhipeng Zhang ◽  
Xiang Liu ◽  
Keith Holt
Keyword(s):  
Fault Tree Analysis ◽  
Contributing Factors ◽  
Train Control ◽  
Ongoing Work ◽  
Positive Train Control ◽  
Stub End ◽  
High Level ◽  
Operational Impacts ◽  
Speed Enforcement ◽  
Passenger Terminals

A series of end-of-track collisions occurred in passenger terminals because of noncompliant actions from disengaged or inattentive engineers, resulting in significant property damage and casualties. Compared with other types of accidents, end-of-track collision has received much less attention in the prior research. To narrow this knowledge gap, this paper firstly analyzes the safety statistics of end-of-track collisions, then develops a fault tree analysis to understand the causes and contributing factors of end-of-track collisions. With the objective of mitigating this type of risk, this paper discusses the potential implementation of Positive Train Control (PTC) for the passenger terminal. This paper primarily focuses on the enforcement of the two most widely implemented systems, the Advanced Civil Speed Enforcement System (ACSES) and the Interoperable Electronic Train Management System (I-ETMS). For each implementation scenario, the Concept of Operations (ConOps) is proposed that depicts high-level system characteristics for the proposed PTC system enforcement at stub-end terminals. Ongoing work is being carried out by the authors to fully evaluate the cost-effectiveness and operational impacts of enforcing PTC in terminating tracks to prevent end-of-track collisions.

Avoiding Increased Trip Times and Other Operational Impacts When Implementing Positive Train Control

2010 ◽  
Author(s):  
Davis Dure
Keyword(s):  
Speed Limits ◽  
Transit Systems ◽  
Speed Reduction ◽  
Train Control ◽  
Trip Time ◽  
Positive Train Control ◽  
Cab Signal ◽  
Operational Impacts ◽  
Speed Enforcement ◽  
Speed Restrictions

Implementing safety systems on railroads and transit systems to prevent collisions and the risks of excess speeds often come at the price of lengthened trip time, reduced capacity, or both. This paper will recommend a method for designing Positive Train Control (PTC) systems to avoid the degradation of operating speeds, trip times and line capacities which is a frequent by product of train-control systems. One of the more significant operational impacts of PTC is expected to be similar to the impacts of enforcing civil speed restrictions by cab signaling, which is that the safe-braking rate used for signal-system design and which is expected to be used for PTC is significantly more conservative than the service brake rate of the train equipment and the deceleration rate used by train operators. This means that the enforced braking and speed reduction for any given curve speed restriction is initiated sooner than it otherwise would be by a human train operator, resulting in trains beginning to slow and/or reaching the target speed well in advance of where they would absent enforcement. This results in increased trip time, which can decrease track capacity. Another impact of speed enforcement is that it often results in “underspeeding.” In a cab-signal (and manual-train-operation) environment, it has been well documented that train operators typically operate two or three mph below the nominal enforced speed to avoid the risk of penalty brake applications. Target and location speed enforcement under PTC is likely to foster the same behaviors unless the design is prepared to mitigate this phenomenon. While the trip-time and capacity impacts of earlier braking and train-operator underspeeding are generally marginal, that margin can be very significant in terms of incremental capacity and/or resource for recovery from minor perturbations (aka system reliability). The operational and design methodology that is discussed in this paper involves the use of a higher unbalance (cant deficiency) for calculating the safety speed of each curve that is to be enforced by PTC, while retaining the existing maximum unbalance standard and existing speed limits as “timetable speed restrictions”. Train operators will continue to be held responsible for observing the timetable speed limits, while the PTC system would stand ready to enforce the higher safety speeds and unbalance should the train operator fail to properly control his or her train. The paper will present a potential methodology for calculating safety speeds that are in excess of the normal operating speeds. The paper will also calculate using TPC software the trip-time tradeoffs for using or not using this potential concept, for which there are some significant precedents. Other operational impacts, and proposed remedies, will be discussed as well. These will include the issues of total speed enforcement versus safety-speed enforcement, the ability of a railroad’s management to perform the speed checks required by the FRA regulations under normal conditions, and the operation of trains under occasional but expected PTC failures.

Application of Fault Tree Analysis and Swiss Cheese Model to the Overspeed Derailment of Puyuma Train in Yilan, Taiwan

2020 ◽  
Vol 2674 (5) ◽  
pp. 33-46
Author(s):  
Jyh-Cherng Jong ◽  
Yung-Cheng (Rex) Lai ◽  
Cheng-Chung Young ◽  
Yu-Fu Chen
Keyword(s):  
Process Analysis ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Swiss Cheese ◽  
Contributing Factors ◽  
Tree Analysis ◽  
Train Control ◽  
Swiss Cheese Model ◽  
Express Train ◽  
Cheese Model

On October 21, 2018, a Puyuma express train went overspeed through a sharp curve and derailed in Yilan, Taiwan. This accident resulted in 18 fatalities and 267 injuries. Although such accidents occur once in a while worldwide, this case of an overspeed derailment from a train-set equipped with an automatic train protection (ATP) system (similar to the function of Positive Train Control (PTC) in the U.S.) is rare. A temporary investigation team was appointed by the Executive Yuan, the highest administrative organ in Taiwan, and the investigation was completed within 2 months. This paper presents the process, analysis, findings, and recommendations from the accident investigation. The accident was first analyzed using fault tree analysis to identify potential causes and contributing factors of this derailment. The results were then categorized into layers of defenses by using a Swiss cheese model. We further extended the original Swiss cheese model to a “time-dependent Swiss cheese model” to demonstrate how the barriers were penetrated at different times by incorporating the timestamps of important events. Another modified Swiss cheese model called “causal relationship Swiss cheese model” was presented to further demonstrate the causal relationships. With the proposed process and models, the immediate causes and contributing factors were quickly identified and presented in a way that could be easily understood by the general public. The results showed that the ATP system (or the PTC) cannot guarantee 100% safety. A review of the safety culture and corresponding procedures is important to ensure the safety of railway operations.

Field Testing Plan for Positive Train Control Enforcement in Passenger Terminals

2020 ◽  
Author(s):  
Zhipeng Zhang ◽  
Xiang Liu ◽  
Keith Holt
Keyword(s):  
United States ◽  
Field Tests ◽  
Field Testing ◽  
The United States ◽  
Test Sequence ◽  
Benefit Cost Analysis ◽  
Stub End ◽  
Speed Enforcement ◽  
Passenger Terminals ◽  
Operational Impact

Abstract In the United States, a train moving onto a terminating track at a passenger terminal relies on the train engineer’s operation. Currently, there are no mechanisms installed at the U.S. passenger terminals that are able to automatically stop a train before reaching the end of the track if an engineer fails to do so. The engineer’s actions determine whether the train will safely stop before the end of the terminating track. Thus, incapacitated or inattentive engineer operation would result in end-of-track collisions, such as the New Jersey Transit train accident at Hoboken Terminal in 2016. Currently, PTC enforcement is not required in passenger terminals. In an ongoing project tasked by the Federal Railroad Administration, we study the cost-effectiveness and operational impact of possible PTC enforcement to prevent end-of-track collisions. Specifically, a Concept of Operations (ConOps) was developed to outline the proposed plans to implement two of the most widely used PTC types, namely the Advanced Civil Speed Enforcement System (ACSES) and Interoperable Electronic Train Management System (I-ETMS). This paper describes in-field testing of the ConOps in ACSES-type terminal. In the planned field test, a train equipped with one locomotive and at least one passenger coach would be tested on platform tracks in a selected passenger terminal. These are three major testing components, which are test equipment, test track, and recorded information for each test sequence. Firstly, in terms of equipment, a traffic cone will be placed on the track to simulate a bumping post. In ACSES system, two sets of transponders are programmed to require a positive stop within a specified distance and mounted to the cross ties at specified positions. Secondly, a yard track will be used to test the feasibility of this exercise at the beginning. Upon successfully completing the test multiple times, a series of tests will also be made on the studied platform track. Thirdly, each test run should record the distance from the head end of the test train and the traffic cone for each test run. In addition, ACSES system should also record the information on the ACSES display as it passes the first and second transponder set, respectively. Overall, the field tests presented in this paper, along with previous work in benefit-cost analysis and operational impact assessment, can contribute to an assessment of the proposed PTC implementation at stub-end terminals in the United States in order to effectively and efficiently prevent end-of-track collisions.

Positive Train Control System Testing

2014 ◽  
Author(s):  
Scott Gage ◽  
Alan Polivka ◽  
Shad Pate ◽  
W. David Mauger
Keyword(s):  
Control System ◽  
Test Bed ◽  
Radio Communications ◽  
Railroad Industry ◽  
Technology Center ◽  
Train Control ◽  
Train Control System ◽  
Positive Train Control ◽  
And Performance ◽  
Speed Enforcement

For the last several years, the railroad industry has been developing various elements for typical Positive Train Control (PTC) systems and has been demonstrating their functionality. In order to test the capabilities of these systems, Transportation Technology Center, Inc. (TTCI), the industry, and Federal Railroad Administration (FRA) have guided and funded the development of the PTC Test Bed located at the Transportation Technology Center (TTC) in Pueblo, Colorado. Recent upgrades to the PTC Test Bed at TTC have enhanced the capabilities to support on-track testing of Interoperable Train Control (ITC aka I-ETMS®) system/subsystem functionality (including radio communications), interoperability, and performance/stress characterization. Now, onboard, wayside, and office additions have been made for the PTC Test Bed to support testing associated with Advanced Civil Speed Enforcement System (ACSES) II systems and equipment. In support of train control objectives, TTCI has also implemented a broken rail detection test bed, which has produced some interesting results.

Prevention of End-of-Track Collisions in Passenger Terminals via Positive Train Control: Benefit-Cost Analysis and Operational Impact Assessment

2020 ◽  
Vol 2674 (7) ◽  
pp. 16-28
Author(s):  
Zhipeng Zhang ◽  
Xiang Liu ◽  
Keith Holt
Keyword(s):  
Cost Analysis ◽  
Impact Assessment ◽  
Rolling Stock ◽  
Second Phase ◽  
Benefit Cost Analysis ◽  
Train Control ◽  
Positive Train Control ◽  
Benefit Cost ◽  
Passenger Terminals ◽  
Operational Impact

End-of-track collisions at passenger terminals have raised safety concerns because of their potentially severe consequences such as infrastructure and rolling stock damage, service disruption, and even casualties. As introduced in the previous study sponsored by the U.S. Federal Railroad Administration, the implementation of Positive Train Control (PTC) systems at passenger terminal stations could potentially prevent end-of-track collisions. As the second phase of that project, this paper aims to provide a comprehensive evaluation of the proposed concept of operation via quantitatively identifying the safety benefits, incremental costs, and operational impacts associated with PTC enforcement on terminating tracks. The benefit-cost analysis indicates that the safety benefits may exceed the incremental costs over a 20-year period under specified circumstances and assumptions. In addition, the preliminary results disclose that the operational impact in PTC enforcement should be negligible, except for the rare occurrence of wayside interface unit (WIU) failure or radio failure in the Interoperable Electronic Train Management System (I-ETMS)-type PTC system that would result in a stop well short of the targeted point and potentially delay both onboard passengers and inbound/outbound trains. Both benefit-cost analysis and operational impact assessment methodologies are implemented in a decision tool that can be customized for different terminals with heterogeneous infrastructure and operational characteristics and be adapted to other transportation modes.

Troubleshooting and Performing Diagnostics on Amtrak’s ACSES System Using PHW’s Inc. ACSESView Software

2009 ◽  
Author(s):  
Lamont B. Ward
Keyword(s):  
Control System ◽  
Train Control ◽  
North East ◽  
Train Control System ◽  
Positive Train Control ◽  
Maintenance Activities ◽  
Speed Enforcement ◽  
Maintenance Personnel

The Advanced Civil Speed Enforcement System (ACSES) is a positive train control system used on Amtrak’s North East Corridor (NEC) developed by PHW, Inc. To perform maintenance activities, the system can be downloaded from the On Board Computer (OBC) and the events can be displayed on a laptop using the ACSESView software. This paper will present how the software is used by maintenance personnel and engineers to troubleshoot and maintain the system.

scholarly journals Implementation of and experiences with new automation

2000 ◽  
Vol 22 (6) ◽  
pp. 199-202 ◽  
Author(s):  
Ifte Mahmud ◽  
David Kim
Keyword(s):  
Quality Assurance ◽  
Implementation Process ◽  
Regulatory Compliance ◽  
Contributing Factors ◽  
The Future ◽  
Industry Automation ◽  
High Level ◽  
Automation Technology ◽  
And Robotics ◽  
Testing Group

In an environment where cost, timeliness, and quality drives the business, it is essential to look for answers in technology where these challenges can be met. In the Novartis Pharmaceutical Quality Assurance Department, automation and robotics have become just the tools to meet these challenges. Although automation is a relatively new concept in our department, we have fully embraced it within just a few years. As our company went through a merger, there was a significant reduction in the workforce within the Quality Assurance Department through voluntary and involuntary separations. However the workload remained constant or in some cases actually increased. So even with reduction in laboratory personnel, we were challenged internally and from the headquarters in Basle to improve productivity while maintaining integrity in quality testing. Benchmark studies indicated the Suffern site to be the choice manufacturing site above other facilities. This is attributed to the Suffern facility employees' commitment to reduce cycle time, improve efficiency, and maintain high level of regulatory compliance. One of the stronger contributing factors was automation technology in the laboratoriess, and this technology will continue to help the site's status in the future. The Automation Group was originally formed about 2 years ago to meet the demands of high quality assurance testing throughput needs and to bring our testing group up to standard with the industry. Automation began with only two people in the group and now we have three people who are the next generation automation scientists. Even with such a small staff,we have made great strides in laboratory automation as we have worked extensively with each piece of equipment brought in. The implementation process of each project was often difficult because the second generation automation group came from the laboratory and without much automation experience. However, with the involvement from the users at ‘get-go’, we were able to successfully bring in many automation technologies. Our first experience with automation was SFA/SDAS, and then Zymark TPWII followed by Zymark Multi-dose. The future of product testing lies in automation, and we shall continue to explore the possibilities of improving the testing methodologies so that the chemists will be less burdened with repetitive and mundane daily tasks and be more focused on bringing quality into our products.

FOOD SAFETY KNOWLEDGE, ATTITUDES AND PRACTICES AMONG FEDERAL UNIVERSITY OF AGRICULTURE STUDENTS IN ABEOKUTA

2017 ◽  
Vol 15 (1) ◽  
pp. 94-107
Author(s):  
M O ADEGUNWA ◽  
M I SANUSI ◽  
H A BAKARE ◽  
A M OMEMU
Keyword(s):  
Food Safety ◽  
Contributing Factors ◽  
Safety Attitudes ◽  
Attitudes And Practices ◽  
Handling Practices ◽  
High Level ◽  
Almost All ◽  
The University ◽  
Safety Knowledge ◽  
Safety Attitude

Improper practices, poor attitudes and lack of knowledge by food handlers are contributing factors for the spread of foodborne diseases. Food safety knowledge is an important factor in improving food safety practices and subsequently food safety attitude. This study is aimed at exploring the food safety knowledge, practice and attitude of FUNAAB students. A self completed questionnaire was answered by randomly selected 270 students from each of the nine (9) colleges in the university and analyzed using SPSS software. The study revealed that almost all of the students had a high level of food safety awareness but the knowledge was not to large extent translated into practice. Majority of the students also had good food safety attitudes as many of them are willing to change their food handling behav-iour when they know they are incorrect (94.8%). The study further revealed similar level of food safety knowledge between the male and female. Despite the level of students’ knowledge, their choice of eating place on campus was determined by the price of the food. This study therefore concluded that good knowledge of food safety does not determine students’ safe handling practices and choice of eating place.Keywords: Food safety

Sign in / Sign up

Export Citation Format

Share Document