Peter Burns MBA, BAppSci (Elect), FIRSE, CPEng, FIEAust

PYB Consulting

As signalling technology moves from the world of the fixed signal to the world of Communication Based systems, one major issue which arises is how to deal with the legacy unfitted train.
Traditionally, the available answers to that issue have been:
    •    Don’t allow non-fitted trains to run on the relevant part of the network (the captive fleet option); or 

    •    Build the Communications based System as an overlay on traditional signalling infrastructure including its 
fixed signals. 
This second option in particular denies the railway any of the cost benefits associated with the new technology and acts as a barrier to its use. 
This paper will explore the alternative – to make the signalling for the unfitted train an overlay on the underlying Communication Based Signalling, rather than the other way around. 
The method for doing this will be explored via the example of the Electronic Virtual Trainstop. We do not have one of these right now, but we are in a position to develop its specification.


In a world where the signal engineer has involvement in defining the train’s on-board systems, this paper will explore three specific subsystems and the interfaces between them needed to achieve operability. One subsystem is part of the infrastructure, associated with the communications based signalling itself. The second is conceptually portable, but operationally part of the equipment taken on board the train. The third is the electronic virtual trainstop itself – the core on-board system. 
The issue with defining an on-board system for an unfitted train seems apparent just looking at the terms. In reality, “lack of fitment” covers a range of possibilities, ranging from no fitment whatsoever, through a very basic system-independent facility (here we find the Electronic Virtual Trainstop) to a train fully fitted with somebody else’s Communication Based signalling. Each possibility will be discussed. 
By defining the intermediate system and some basic open interfaces, the paper will show how the issue of interoperability can be managed for the full range of possible trains.

Somnath Banerjee B. Tech, FIRSE, MIEEE, MIRSTE, RPEQ

The history of “Byte by Byte” Railway signalling is also the history of new technology for Railway Signalling.  Any discussion on this subject will remain incomplete unless we know how to manage new technology bite by bite.

The introduction of new technology in Railway Signalling systems, more often than not, is a challenging exercise. This assumes significant importance because compared to the investment and its physical visibility its impact is very high. This paper discusses how the challenges can be managed in a structured manner.

Some important steps can help reduce the labour pains of introduction of new technology in a Railway signalling system.
    .    a)  Clear understanding of the operator’s need for the new technology. 

    .    b)  Choosing the right technology to match the operator’s expectations . 

    .    c)  Structuring the development to match the operator requirements using several independent blocks. This is 
again an important step and if not thought out properly, it can make changes to the design difficult and costly. 

    .    d)  Designing the sub-systems with enough resilience to allow with minimum effects to other sub-systems. 

    .    e)  A strategy for testing the sub-systems to ensure minimum changes to it once the sub-systems are integrated into a single system

Brett Baker BE, MBA, MIRSE, MRTSA

Queensland Rail

The principle form of train protection for the metropolitan rail region of Queensland has been the Automatic Warning system. In 1988 the ERICAB 700 Automatic Train Control system was introduced onto the regional North Coast Line of the Queensland Rail network. It was followed in 1994 by the WESTECT Automatic Train Protection system, which now provides train protection for over 2500 route kilometres on the regional rail network within Queensland. The Automatic Warning System remains the train protection system stalwart for the metropolitan rail network, ERICAB is no longer in use and the WESTECT Automatic Train Protection system is all but life-expired, so Queensland Rail now looks beyond these systems for the future application of train protection for the rail network – European Train Control System.

Federico Nardi BCompE (Hons), RE(OIGenova)

Ansaldo STS Australia Pty Ltd

Howard Revell BA, CEng, RPE (Elec), RPEQ (Elec), HonFIRSE MIEEE


Ansaldo STS Australia Pty Ltd

This paper focuses on the differing aspects of the migration processes and methods involved in transforming existing legacy metro and mainline signalling systems over to CBTC or ERTMS based systems. Three of Ansaldo STS’s current European brownfield projects have been selected to provide scenarios, with each scenario offering a specific approach to a migration methodology that satisfies the particular nature of the project and the needs of the customer organisation funding the project.

The three scenarios relate to three different customer organisations:

• Stockholm Metro Red Line - CBTC for Storstockholms Lokaltrafik (SL) 

• Haparandabanan, part of the ESTER Project - ERTMS L2 for Trafikverket 

• Florence – Rome HSL upgrade - ERTMS L2 for Rete Ferroviaria Italiana (RFI.


These scenarios provide a useful background concerning the need for effective system planning to support efficient design and implementation tasks, without causing disruption to revenue service traffic. However, despite this approach being very well established and practiced in our industry, it is very costly in terms of time, effort and funds and perhaps there is an alternative migration mitigation approach that could be investigated and adopted. These scenarios raise a number of points that may be usefully heeded by others involved in similar migration projects.

Introduction
 Level crossings represent high risk exposure for railway operators.
 Obligation for engineers and railway operators is to ensure level crossing risks are seen to be reduced So Far As Is Reasonably Practicable (SFAIRP).
 Grade separation is best solution but how can we ‘sweat’ level crossing assets?
 Once you have ‘lights, booms and gongs’ what then?
 Road complexity, number of cars, type of traffic, frequency of trains all increase risk
 What else can we do?

Assuming you get the job to implement or update a new level crossing: You will be confronted with lots of stakeholders,
influencers and legislative guidelines. The national regulator is giving you a certain framework. Investors, be it the
railway operator or the infrastructure owner usually limit your ambitions in terms of money. There is only a limited budget
available and it needs to be spent wisely. In contrast, other stakeholders such as end users or neighbours, living next to
a crossing, usually tell you exactly how things should work - or more often - how they shouldn’t.
This document addresses general areas of conflict. Furthermore, it shows how national regulator, infrastructure owner or
operator can influence the value for money proposition to achieve improved cost structures or whole of life costs as well
what suppliers can do in order to ensure lower cost and safe level crossings. The paper highlights cost savings due to
better selected requirements and provides a simple example.

Signal engineers and train operations staff often misunderstand each other when talking about headway.

When someone in the operations team refers to headway, they actually mean the interval between trains expressed in minutes. They assume that the interval between trains is enough to deliver a reliable on-time service.

Signal engineers however calculate headway as the absolute minimum time between following trains that will allow drivers to retain line speed without having to apply brakes due to passing yellow signals.

The signal design will generally try to space signals so that there is a fairly uniform headway across a section of line. The worst headway on the line sets the "ruling headway" for the line. This is sometimes called the theoretical signalling headway. Trains travelling closer than the ruling headway will meet at least one yellow signal and be forced to apply brakes, and will therefore lose time. This in turn will delay the following train and so on, causing cascading and compounding delays.

Several factors contribute to achieving reliable train frequencies, such as the permitted line speed, driver behaviour, train acceleration & braking rates, train length, signalling principles (such as overlap length), planned station dwell time, and most importantly, passenger behaviour.

This paper provides a brief background on classical headway theory; some insight on how track speed and station dwell time impact on achievable capacity; a case study to demonstrate that terminal stations may pose a greater constraint on capacity than the signalling; and a suggested method to allow quick assessment of achievable capacity on a new line.

Modern in-cab signalling can increase capacity beyond the limits of conventional legacy systems and also improve service punctuality. The present market for in-cab signalling is divided in two segments. For mainline railways on a national level, the European Train Control System (ETCS) is preferred by railway operators well beyond the reach of European legislation. For high performance metro-style city railways, Communications Based Train Control (CBTC) is the solution of choice. Both technologies have different purposes and histories and consequentially developed distinct strengths but also weaknesses.

The suburban railway systems in the major Australian cities appear in a transition from a mainline legacy to high capacity metro ambitions. The technology selection between ETCS and CBTC is therefore less straightforward with no clear "right" or "wrong" and examples for either system evolving in Australia. However, operators need to recognise and accept the consequences of selecting either technology.

The paper concludes with an outlook on further development of both technologies, which concentrates on addressing the individual shortcomings while maintaining existing advantages. The evolving subject of "convergence" between ETCS and CBTC will be discussed to assess whether there will be only one "best" signalling technology in the future.

This paper describes components and processes to re-engineering level crossing safety by controlling the movement over level crossings for both road and rail vehicles. This is primarily aimed at highway crossings and in particular remotely located crossings on heavy haulage rail lines.

The rail corridor has always been designated as a permanent way with the train driver as the only stopping control to avoid collisions with obstructions. With the introduction of new technologies and driverless train projects the need to detect obstructions and control the passage of trains across conflict zones such as level crossings has become vital.

These new technologies must be introduced with strict operational guidelines that are fit for purpose. Technology that increases train delays due to false or unreliable alarms is not an acceptable solution.

System components for this design will include

 Duplicated Flashing Lights

 Duplicated Half Boom Gates

 Barrier protection around level crossing equipment locations

 CCTV with integrated crossing state logging

 Obstruction Detection in the crossing zone

 Duplicated Advance Warning Lights

 Road Speed Reduction

 Rumble Strips

 Full Road Pavement Markings and duplicated road signage

 Vital Communications to stop the train

All components play an important role in level crossing protection.

Modern communications based signalling places improved signalling functionality on board the train.

This can be used to enforce conventional temporary speed restrictions using location based authorities. With these the train ensures its speed is maintained below the temporary maximum between two defined points.

In a related class are time based authorities. A time based authority commences at a specified time and continue to a specified event (which is not necessarily time based). Two examples are presented.

The first relates to a requirement to restrict passing speeds within a long tunnel to below a specified maximum (as is the case for the Seikan tunnel in northern Japan).

In this case the signalling system is aware of the location and authorized speed of the two passing trains in advance. With this knowledge a passing point can be predicted in terms of location. However, a speed restriction based on this criterion can be shown to be unsound as a provider of safety. Thus a safety benefit is obtained by defining the passing point in terms of time; a time based authority emerges.

The second relates to level crossing protection.

It is conventional in a class of signalling to require a train to obtain an authority to cross a protected level crossing.

Communications base signalling allows a train to communicate its arrival time to the level crossing as part of the process for obtaining that authority. This is another class of time based authority – the train obtains authority to cross at a specified time.

Once communicated, the train is able to regulate its progress safely to ensure it does not arrive prior to the specified time. The crossing is able to ensure that the standard warning is provided prior to the authorised arrival time.

The paper explores the characteristics of, and requirements for time based authorities.

Anjum Naweed BSc (Hons), MSc, PhD, CPE

Central Queensland University

Jeanette Aitken BE (Hons), MEngSc, Dip VET, MIEEE, AMIRSE

Competency Australia

Trains are the fastest and heaviest of land vehicles and the intent of railway systems design is to transport them safely and efficiently from one location to another. Track workers and maintainers are the unsung heroes of rail safety but are often placed in dynamic and hazardous situations, rendering them vulnerable to the very things they work to protect. The dramatic irony inherent in their work is addressed by the “Lookout working’ concept of safeworking where a range of technologies are used to assist in the provision of acceptable margins of personal safety from approaching trains.

This technical paper aims to conceptualise the degrees of control and types of technologies used to protect the safety of track workers and maintain the security of their work sites. Presented from a human factors perspective using a systems thinking approach, the paper articulates key lessons that can be drawn from previous accidents and “near-misses” associated with failures in track worker protection, which have been investigated in the context of railways in the UK and Australasia. The objective of the paper is to evaluate the viability of utilising smarter technologies to achieve improvements in maintenance track worker safety within the Australian railway environment.

Thomas McPeake  MIET  AMIRSE

Arcadis

Axle counter technology is a proven, reliable method of track vacancy detection suited for a variety of installations. But despite the many advantages this technology can offer it has not rivalled conventional track circuits as a form of track vacancy detection within single line sections in Australia. This perhaps can be attributed to a number of inherent issues that impeded the effectiveness of axle counters system when configured to transmit data over long distances. However, in recent years there have been a number of advancements in both axle counter and telecommunications technology which have overcome some of these inherent issues. This paper investigates whether axle counter technology is now a smarter solution for single line sections, or if conventional track circuits still provide the best solution.

Bruno Lambla

Product Manager, TTG Transportation Technology, Australia

This paper first focuses on DAS technology insertion into the reality of the legacy of complex railway assets and provides one of TTG’s return on experience on DAS deployment.

In a second stage, we focus on steps for integration of DAS with other railway signalling systems. Integration is inevitable and will add value and capability to the DAS offer. Dynamic optimisation of standalone DAS can deliver energy savings of around 5 to 18% to train operating companies. Integration with traffic management systems (Connected DAS) will allow DAS to dynamically take into account other trains’ trajectory. This will allow to optimise the network capacity.

DAS remains a SIL 0 (SIL 1 in the case of C-DAS) system but can operate with Safety Systems such as ETCS. Integration with ETCS will require ETCS display to be modified so that the DAS graphical interface can be represented on the ETCS screen. This integration to a single visual display will ensure the driver can’t get any conflicting advice between DAS and ETCS. The conflicts will be managed through ETCS accepting or ignoring advice coming from DAS.
Integration has started and will continue so that information can be shared improving situation awareness. The value of the DAS advice will be increased. This integration will be made possible by deployment of traffic management systems, new telecommunications allowing constant and secure information flow, ETCS implementation.

Paul Gray B.Eng., M.Eng., Ph.D. Cohda Wireless
Paul Alexander B.Eng., M.Eng., PhD. Cohda Wireless

In 2010 Cohda Wireless conducted a feasibility study for the use of Dedicated Short Range Communications (DSRC) for improving rail level crossing safety.

DSRC is the globally coordinated standard for Cooperative Intelligent Transportation Systems (ITS). It combines GPS and wireless communication in dedicated spectrum at 5.9GHz. Safety-of-life applications, such as cooperative collision avoidance are the key feature of DSRC, and the 5.9GHz spectrum includes a communications channel dedicated to cooperative safety applications.

Vehicles use DSRC to share information by continually broadcasting their location, speed, direction, vehicle type and size, and additional status information. The DSRC system also includes a processor that uses local position information, and information received from other vehicles, to accurately detect potential collisions and activate driver warnings. DSRC Roadside Equipment (RSE) allows communications between vehicles and infrastructure, such as railway warning systems.

Peter Burns MBA, BAppSci (Elect), MIRSE, CPEng, MIEAust

PYB Consulting

This paper on Movement Authorities is one of a series on the various elements of the Generic Systems Framework (see figure 1). The issuing of Movement Authorities is distinguished from the setting of a route and the general pre-conditions for the issuing of a Movement Authority stated.

Movement Authorities are shown to be found in all safeworking systems and having characteristics which are common to all of them. The process for issuing a Movement Authority may be characterised as the formation of a contract between the train and the interlocking.

Looking at fixed signal systems, the signal is found to fill three distinct functions, one of which is the communicating of movement authorities.

Turning to ERTMS and CBTC systems, it is shown that their central functionality is of a nature that does not require treatment as a movement authority. Benefits can be obtained by recognising the different natures of the three distinct
functions which are replaced when ERTMS and CBTC systems requirements around those distinct functions appropriately.

Brenton Atchison PhD, BSc, RENG
Michael Bruce BSc Eng, MIRSE

Siemens Ltd. Mobility Division, Australia

This paper describes the experience of implementing the European Train Control System (ETCS) Level One on the Adelaide Metropolitan Passenger Rail Network (AMPRN). The ETCS implementation was part of the broader signalling and communications contract associated with network rail electrification program.

The project commenced in October 2012 and an independently assessed safety case for ETCS was completed September 2015 with first passenger service in November 2016. It is the first operational ETCS system deployed in Australia.

This paper discusses the challenges associated with ETCS trackside engineering and implementation. It describes the key choices in operating principles, contrasts trackside application for the re-signalled and overlay lines, describes rolling stock installation considerations, and system integration methodology.

John Aitken BE SMIEEE MIRSE

Aitken & Partners

Simplifying assumptions are a key to understanding many problems and can be very helpful. Thin, inextensible strings and ideal capacitors make for simple analysis but neither is available for purchase, so their practical usefulness is limited.
Sometimes, simplifying assumptions conceal an underlying problem or distort our understanding. This tutorial paper discusses some situations where assumptions may lead to undesirable outcomes and provides some gentle reminders to exercise caution and be thorough in design, implementation and testing.

Paul Tipper BSc

P.R.Tipper Pty Ltd

The conventional practice of placing signals onto a track layout to meet operational requirements often fails to achieve the aim of the operator. This is because track layouts are developed primarily around geographical constraints and do not consider the dynamics of the operational railway. Equally, signalling which is not shaped by the behaviour it imposes on the train is likely to fail in meeting the operational requirements for the same reasons.

In developing concepts for the Sydney network Sydney Trains has turned the conventional process on its head. The new process started with an analysis of the operational needs to determine the type of train and driver behaviour required to achieve them. This behaviour was then further analysed to determine the likely signalling arrangements which would facilitate that behaviour. Finally, track layouts were devised that were compatible with the signalling arrangements. These layouts were then passed on to the track team to develop into alignments compatible with the geography.

Bill Palazzi B.Eng (Elec.) MIRSE

palazzirail

The layout and configuration of a signalling is a key factor in defining the capacity of a railway. However, the signalling system is not the only factor influencing capacity, and in fact many of the other issues can compromise the capacity delivered by the signalling system.

Capacity on any given infrastructure is partially about what is designed, but is also about how it is operated and what external influences there are. In this way, a railway is less like a measuring tape which provides a consistent and repeatable outcome, but is more like a tool where the quality of the outcome can be poor, acceptable or outstanding depending on the skill of the craftsperson.

To assist the understanding of railway capacity, this paper has outlined a hierarchy of influences on capacity which progressively constrain what is achievable in operation. The hierarchy incudes four levels of influence, as below:

• Tier 1 Influences - Inherent factors; baseline infrastructure configuration
• Tier 2 Influences - Design factors; signalling theoretical capacity
• Tier 3 Influences - Achievable capacity: what can be timetabled
• Tier 4 Influences - Delivered capacity; day of operation impacts.

The four tiers of influence help define how the various elements that make up capacity relate to each other, including the relationship between the signalling design and other influences. The tiers also help to clarify where signalling can help, but also the areas where signalling has little or no influence.

Finally, whilst optimising train throughput might be valuable, it is not the only consideration. Attributes such as safety, availability, reliability and quality of service are also important customer expectations; these are reflected in the need to find the most appropriate capacity balance for each railway operation.

Trevor Moore  BEng, MBA, FIRSE, FIE Aust 

Australian Rail Track Corporation

The Australian Rail Track Corporation was established in 1998 to manage the below rail assets from the devolution of Australian National Railways. It subsequently set up leases for the interstate rail network in Victoria and New South Wales. It now covers 5 states in Australia. It manages track and access for trains from Kalgoorlie in Western Australia through Adelaide, South Australia to Melbourne, Victoria and on to Sydney, New South Wales and finishing just outside of Brisbane, Queensland. It is an accredited rail organisation and manages rail operations, signalling, track and civil infrastructure.

The signalling principles are represented in signalling standards and in the network operating rules. The Rules detail how the train drivers and the network controllers/signallers view and operate on the rail network.

The signalling principles of a railway cover design, construction, testing, maintenance and operation. All of the System Life Cycle elements incorporate principles that govern the manner in which the signalling system operates.

ARTC has inherited the rail networks, signalling infrastructure and signalling principles of the long standing railways in South Australia, Victoria and New South Wales. For the past ten years these inherited signalling standards have been reviewed and merged. This is an ongoing task and will continue as the railway adapts and grows and new technology is introduced.