CBTC: Are you a visionary or a skeptic?

Dr. Alan F. Rumsey, P.Eng., FIRSE, has spent his entire career in railway signaling and communications, and is one of the driving forces behind CBTC (communications-based train control) for rail transit.

Recently retired from Parsons, Dr. Rumsey is an independent consultant (Rumsey Transit Systems Consulting, Kingston, Ontario). He is currently advising the Toronto Transit Commission on its CBTC program.

The following is an address Dr. Rumsey gave to an IRSE (Institution of Railway Signal Engineers) CBTC Seminar in Toronto on Dec. 1, 2016, entitled “Are you a visionary or a skeptic?”

Are you a person who embraces change, with original ideas about what the future will or could be like? Are you prepared to take risks to achieve this vision? Or are you a person who is cautious of change, questioning and skeptical of the presumed benefits of change? Are you reluctant to take on risks associated with change? Or perhaps you are a little of both, depending on the circumstances?

The reason for me asking these questions – and these are questions I am asking myself as well as all of you here – should hopefully become a little clearer later in my talk.

Let me start at the beginning, and go back 40 years to the early 1970s.

At that time I was pursuing an academic career at the University of Manchester Institute of Science & Technology (UMIST), in England and was completing a PhD research project into the “Application of Control Techniques to Transportation Systems.”.

I published my thesis in 1974 and in this thesis I included the following definition of an “ideal” transportation system:

An “ideal” transportation system should be capable of moving people safely and efficiently from any given origin to any given destination with minimum delay and at a reasonable cost. Vehicles should be available “on demand” and should be quiet, comfortable and pollution free. A direct origin-to-destination service implies a high-density network linking all major centres of activity with frequent access points. Such a network would almost certainly be on or above ground level because of the high cost of tunnelling, and therefore must be designed so as not to intrude on the urban environment. This suggests a system of relatively small vehicles travelling on lightweight guideways.” I also went on to say:

Any new transportation mode will undoubtedly be either partially or fully automatic since only by automation can full use be made of the system capacity. With a computer controlled system it is possible for vehicles to travel in safety at much shorted headways and they will no longer be required to operate on a fixed time-table since schedules can be continuously updated to suit fluctuating passenger demands.

What I was describing was in fact one vision for the future that back then was referred to as “Personal Rapid Transit” or PRT.

My research looked at methods of controlling such a high density, fully automated transit system, including something that at the time was referred to as “the synchronous moving-cell control philosophy” – not quite moving block or CBTC, but a step in that direction.

Interestingly, as part of my research I also looked at safe braking models which did not assume a brick-wall stop of the leading vehicle and noted that the smaller the safety factor, and hence the greater the capacity, the more information a vehicle would require about the preceding vehicles and hence the more complex the communication and control systems.

This vision for PRT never materialized – at least as it was envisaged at the time with automated transit vehicles running on a network of elevated guideways.

However, a future where we have autonomous road vehicles operating on our highway networks, with vehicles requested via our iPhones with an Uber-like app may not be that far away!

With respect to operating trains at less than safe braking distance to the train ahead, it is interesting to note that such a concept now features in national and international research agendas in Europe, such as the UK Railway Technical Strategy and the European Shift2Rail research initiative. There is an interesting article in the February edition of IRSE News on this topic.

In 1977, I emigrated to Canada.

At that time, the Ontario Provincial Government had invested in a company called the Urban Transit Development Corporation (UTDC) with a vision and a mandate to develop a new mode of urban transit that would fill the gap between high capacity (but expensive) subways and lower capacity (but cheaper) streetcars or light rail transit. They called this new mode an “Intermediate Capacity Transit System” or ICTS, and as a first step developed a Concept of Operations for such a system to meet typical urban transit needs.

This was a transit mode that ultimately was implemented in Vancouver in 1986 as the SkyTrain system. <

I do find it somewhat ironic that the subway versus LRT debate continues to this day in Toronto, and no one appears to remember that it was Ontario that actually developed a solution to this dilemma some 40 years ago, but failed to embrace the technology the way Vancouver (and other cities around the world) have.

It is interesting to note that there are now more route kilometers of Skytrain built in Vancouver over the last 30 years than route kilometers of subways built in Toronto over the last 60 years!

The vision for ICTS/SkyTrain embraced many of the earlier visions of PRT, with respect to fully automated (driverless), small, lightweight vehicles, operating on lightweight elevated guideways, with frequent stations, integrated into the urban environment.

The original Skytrain deployment on the Expo Line in Vancouver for example included:

• A new right-of-way (predominantly a lightweight, pre-cast elevated guideway structure).

• New vehicles (with steerable trucks capable of operating quietly around sharp curves).

• A new propulsion system (with linear motors capable of operating on steeper grades, independent of wheel/rail adhesion).

• A new train control system supporting short-headway, fully automated, moving-block operations (the first major CBTC application).

• A new control center.

• A new maintenance & storage facility (with a fully automated yard supporting driverless close-up and coupling of trains).

• A new Operations & Maintenance organization.

There was virtually nothing in the original SkyTrain implementation that was “off-the-shelf” and “service-proven.”

However, Skytrain had to be operational in time to support the 1986 World Exposition on Transportation and Communication in Vancouver, and it was!

This was my first experience of the benefits of “one team” approach to project delivery, with all parties working collaboratively to a common vision.

Also, as someone who grew up during, and was inspired by, the American Space Program in the 1960s, this was also a time where I embraced the concept of “Failure is not an Option.”

Going back to my original questions regarding Visionaries and Skeptics, not withstanding the successes of SkyTrain, there were many skeptics of CBTC in the early days who argued that CBTC technology was unproven, that the claims of CBTC were unrealistic, that conventional signalling systems could offer similar performance at less cost and less risk, and so on.

The industry was “comfortable” with fixed block, track circuit-based systems that had been around for many decades. For CBTC to become accepted as a the “next generation” of signalling technology, therefore took individuals with a vision to make it happen; individuals who were willing to embrace new technology systems as a means of making step-change improvements in the safety and operational efficiency of transportation systems. This included:

• The vision of the early promoters of PRT systems.

• The vision of the Ontario Provincial Government to invest in a new mode of transportation.

• The vision of Vancouver to embrace this new transportation mode and adopt a totally unproven system as the backbone to its rail transportation infrastructure.

• The vision of other major transit agencies around the world such as New York, London, Paris and Hong Kong, for example, who saw the benefits, accepted the implementation challenges, and were early adopters of this technology.

So, where are we now, and where do we go from here?

Today, I think we would all agree CBTC is a success story. And I would suggest that this is at least in part because a balance was ultimately achieved between the goal of the visionary and the often-legitimate questions raised by the skeptic.

By-and-large, the industry has now become “comfortable” with CBTC and moving block systems.

While the safety and operational performance benefits of CBTC are now well proven, the challenges of implementing CBTC on an operating transit system remain. As such, the current “mantra” in the CBTC-world is “use a service-proven CBTC product with minimum adaptation”. Indeed, as an independent consultant, now advising transit agencies as to the least risk approach to implementing CBTC on an operating railroad, this is a mantra I would aggressively promote.

But there is something we need to watch out for here. For those of us that have been associated with the development and deployment of CBTC over the past 40 years, we must be a little cautious.

As visionaries of the past, are we in danger of now becoming the skeptics of the future? Questioning and resisting further changes in the technology?

We live in an age where someone can spend their whole career engaged in a specific technology, only to find that at the end of their career that this technology has become obsolete and is no longer in demand. In my case, I have spent my whole career of some 40 years involved in one form or another with this technology called CBTC which is still very much in demand. While this is very satisfying, on reflection I do however have to ask the question, why is that? After all this time, why isn’t CBTC obsolete already? Indeed, why do we still need conferences and seminars to discuss and debate CBTC?

I would suggest that CBTC, as it exists today, is not the end of the line. Indeed, I would suggest it is just the tip of the iceberg as to what new technologies can deliver to rail transportation systems. (Just look at the technology advances over the past 40 years in the automobile industry!)

So, my message to you all today is, by all means listen to us grey-haired old-timers, learn from our experiences, and try to avoid the mistakes we have made in the past. But more important, have the courage to create and pursue your own visions for the future.

We are fortunate to live in a world where we are no longer constrained by technology. We are only constrained by our imagination and our vision.

Go out and exploit that!