Balancing the Service Benefits and Mainline Delay Disbenefits of Operating Shorter Freight Trains

2021 ◽  
pp. 036119812110114
Author(s):  
Adrian Diaz de Rivera ◽  
C. Tyler Dick ◽  
Matthew M. Parkes
Keyword(s):  
Service Quality ◽  
Control Systems ◽  
Transit Time ◽  
Capital Investment ◽  
Time Estimation ◽  
Simulation Software ◽  
Fixed Costs ◽  
Train Control ◽  
Operating Strategies ◽  
High Traffic Volume

Advanced train control systems enabling single-person crews or driverless trains promise to significantly reduce the fixed costs of operating a train, removing a strong incentive for longer trains. For carload freight traffic, operating a given number of railcars in shorter trains enables railroads to improve service quality and revenue through increased train frequencies or more direct trains bypassing intermediate classification yards. However, operating shorter trains increases the total number of trains on existing rail corridors, exacerbating congestion and decreasing network fluidity. Rail Traffic Controller simulation software is used to quantify the potential mainline delay impacts and relative capacity consumption of shorter trains. Different combinations of train length and train type heterogeneity are tested on representative single-track freight corridors. Results indicate that train control systems with moving blocks can mitigate some of the mainline delay impacts of shorter trains, particularly at a high traffic volume, with a mix of train types and a greater proportion of railcars traveling on short trains. Mid-siding crossovers can further boost the effectiveness of moving blocks in managing complex train conflicts caused by train type heterogeneity. Simulation results are used to perform an example railcar transit time estimation illustrating the trade-off between yard connection time benefits and mainline delay disbenefits, and the thresholds at which different operating strategies produce a net transit time benefit. Understanding the mainline delay impacts of shorter trains can assist railroad practitioners formulating long-term capital investment plans, developing future operating strategies, and improving service quality and market share through a short train philosophy.

Increase of Efficiency in Wireless Train Control Systems (ETCS Level 2) by the Use of Actual Packet-Oriented Transmission Concepts

2008 ◽  
Author(s):  
Klaus Jobmann ◽  
Simon F. Ruesche ◽  
Jan Steuer
Keyword(s):  
Control Systems ◽  
Capital Investment ◽  
Rail Transport ◽  
The European Union ◽  
Radio System ◽  
Train Control ◽  
Essential Components ◽  
Expansion Stage ◽  
Level 2 ◽  
Transport Management

The European Rail Transport Management System (ERTMS) was introduced by the European Union (EU) to harmonize the nearly 18 different national train control systems which are currently in use, to accelerate the interoperability of the passenger- and freight-transport and, finally, to increase the utilization of tracks by dynamic train control. The essential components of ERTMS are the train-specific, cellular, professional mobile radio system GSM-R (GSM-Railway) and the so-called European Train Control System (ETCS) which provides, by its second expansion stage (ETCS Level 2), the control- and signalling-information between the train and the related control location via GSM-R in a connection-oriented and wireless way. This wireless and connection-oriented approach will be the bottleneck of the system, which considerably limits the possible number of voice- and data-connections in each cell at the same time and will cause a deadlock of the system, if the number of users will rapidly increase (e.g. accidents, freight depots, lines with a high and dynamic volume of traffic). Within this paper the first part of a packet-switched approach is presented to counteract this expected deadlock by taking into account that the GSM-R infrastructure, which is often already installed by the national railroad operators, also should be used to save the high capital investment of those companies.

scholarly journals The Study of Interoperability Test for Onboard Control System in Railway Condition

2011 ◽  
Vol 2-3 ◽  
pp. 785-790
Author(s):  
Jong Hyen Baek ◽  
Yong Kyu Kim ◽  
Jae Ho Lee ◽  
Hyen Jung Jo
Keyword(s):  
Control System ◽  
Control Systems ◽  
Data Systems ◽  
Test Results ◽  
Simulation Environment ◽  
Train Control ◽  
Interoperability Test ◽  
Critical Characteristics ◽  
Site Test ◽  
Onboard Equipment

For the purpose of improving the future domestic train control systems and securing interoperability, according to the global development trends of train control systems, it is presented that the test results of interoperability between wayside train control systems installed in existed line, and the onboard train control system. Due to the safety-critical characteristics of train systems, the site test in the section where the wayside equipment is installed may lead to a danger against safety. Therefore, by way of constructing a simulation environment of train control systems, the T/R data systems of the equipment for interoperability are confirmed and the interoperability test are obtained by applying these systems to onboard equipment.

Statistical Safe Braking Analysis

2011 ◽  
Author(s):  
David F. Thurston
Keyword(s):  
Control Systems ◽  
System Capacity ◽  
Worst Case ◽  
Stopping Distance ◽  
Train Control ◽  
Classic Theory ◽  
Braking Distance ◽  
Prime Determinant ◽  
Worst Case Approach

The main objective in optimizing train control is to eliminate the waist associated with classical design where train separation is determined through the use of “worst case” assumptions that are invariant to the system. In fact, the worst case approach has been in place since the beginning of train control systems. Worst case takes the most conservative approach to the determination of train stopping distance, which is the basis for design of virtually all train control. This leads to stopping distances that could be far more that actually required under the circumstances at the time the train is attempting to brake. Modern train control systems are designed to separate trains in order to provide safety of operation while increasing throughput. Calculations for the minimum distance that separates trains have traditionally been based on the sum of a series of worst case scenarios. The implication was that no train could ever exceed this distance in stopping. This distance is called Safe Braking Distance (SBD). SBD has always been calculated by static parameters that were assumed to be invariant. This is, however, not the case. Parameters such as adhesion, acceleration, weight, and reaction vary over time, location or velocity. Since the worst case is always used in the calculation, inefficiencies result in this methodology which causes degradation in capacity and throughput. This is also true when mixed traffic with different stopping characteristics are present at the same time. The classic theory in train control utilizes a SBD model to describe the characteristics of a stopping train. Since knowledge of these conditions is not known, poor conditions are assumed. A new concept in train control utilizes statistical analysis and estimation to provide knowledge of the conditions. Trains operating along the line utilize these techniques to understand inputs into their SBD calculation. This provides for a SBD calculation on board the train that is the shortest possible that maintains the required level of safety. The new SBD is a prime determinant in systems capacity. Therefore by optimizing SBD as describes, system capacity is also optimized. The system continuously adjusts to changing conditions.

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