Why SkyTrain technology is taken for granted

Dec 20 2017, 2:48 am

The state of public transit in the Metro Vancouver remains a forefront issue in local politics. In the aftermath of the failed transit plebiscite, planners and local officials are struggling to find the funding to support much-needed expansion projects to ensure present and future transit demands.

And at the centre of some recent discussions is increasingly the usage of “SkyTrain technology” as the backbone for rail rapid transit in the region, particularly after a number of major service disruptions since 2013.

The report suggested SkyTrain is past its prime, but that’s anything but the case – it’s the technology of the future and there are clear benefits and advantages of the system over conventional technologies.

Here is an explanation of how SkyTrain works and how it compares with other systems around the world:

1. There are already plans to fix the problems

Most of the identified issues that have been affecting SkyTrain’s operations in recent years are due to the need for wear-and-tear maintenance, particularly with the Expo Line as many of its components have passed their lifecycle and are in need of replacement.

But the replacement of these components, the replacement of the rail tracks or the electrified third rail, are not unique to SkyTrain. This is a necessary undertaking for every urban rail system in the world as parts wear out from heavy usage and weathering.

In fact, work is already being carried out to replace aging spans of the Expo Line’s rail tracks and electrified third rails, which is a $33-million project to replace 34 kilometres of power rails.

For the past few years, crews have been working on extensive replacements, usually during the late night operating hours and the early morning hours when no trains are running and the system is powered down.

Last week’s shutdown of SkyTrain service in downtown Vancouver was an exceptionally rare incident caused by the same rail track replacement project designed to make the system more reliable. Vibrations from passing trains caused a piece of replacement rail stored in a guideway packet to dislocate and move into the envelope of an incoming train. There is a “one-in-a-million” chance of this occurring, according to maintenance staff.

With the power rail replacement, work is nearing completion as crews are now completing the final replacements on the span from Stadium-Chinatown to Patterson stations. Work is already complete on the other sections of the Expo Line.


Other service shutdowns have been freak accidents, not flaws in design, like the May 22 disruption caused by a late-night fire that destroyed fibre optic communication cables. Crews were performing track grinding as part of regular maintenance work – sparks from the grinding ignited a birds nest underneath the elevated guideway. And on August 29, a fallen tree from the major windstorm caused a tree branch to topple over and hit a train on the Millennium Line.

As for the issues that caused other major disruptions, such as the series of shutdowns in the summer of 2014, an independent review by former Toronto GO Transit president Gary McNeil made 20 recommendations to increase the resiliency of the Expo and Millennium lines.

This includes the installation of a $5-million auto-restart component to the SELTRAC train control automation system. Without the auto-restart, it could take up to hours for trains to return to normal service following a service shutdown as control centre operators currently need to manually reintroduce trains into the system.

Another $6 million will be spent on separating vital systems so that if one system fails, the issues do not escalate and cause other systems to fail.

One of the most expensive recommendations will be the $10-million upgrade of the guideway intrusion system at the Expo Line’s station platforms. The original Expo Line station platform tracks will be upgraded with the latest laser detection intrusion systems, a component that the newer Millennium and Canada lines already have.

As SkyTrain is a driverless automated system, it relies on track intrusion systems at the station platforms to detect foreign objects as the train pulls into a station. If the track intrusion alarm is set off, the trains come to a complete halt to avoid hitting the object.

However, the Expo Line currently uses metal pressure plates for detecting track intrusions, but these plates have become less reliable in recent years due to age and weathering.

All track intrusion systems, both lasers and pressure plates, can easily be set off by objects such as fallen newspapers and pop cans. False alarms with the track intrusion system are the number one cause of short SkyTrain delays lasting between 10 to 15 minutes, and this is a daily occurrence. Any track intrusion situation requires a SkyTrain attendant’s physical presence to clear the tracks and provide control room operators with the green light to resume normal service.

The installation of glass sliding platform edge doors would provide a much more reliable solution, but this component is not compatible on the Expo and Millennium lines as the existing train fleet uses three generations of train models – each with different door spacings. The Canada Line is the only system that can accommodate platform edge doors with relative ease as it uses one model of train.

TransLink has stated that all of McNeil’s recommendations will be implemented over a five-year timeline.

2. The benefits and advantages are taken for granted

What exactly is “SkyTrain technology”? What makes the system unique?

First of all, SkyTrain is a fully-grade separated driverless automated system controlled by the SELTRAC moving-block railway signalling system by Thales, a Toronto-based rail signalling company. The SELTRAC system allows trains to run very closely together in a safe manner.

Full automation of the train system eliminates the costly need for drivers, which greatly increases operational costs and substantially decreases the flexibility of train deployment. With automation, trains can be deployed with ease from the control centre to respond to surge demand from events and service disruptions.

Transit users in the Metro Vancouver region enjoy highly frequent train service that arrives every three minutes or less during peak and midday hours on weekdays.

With some modest improvements and the expansion and lengthening of the train fleet, in the future both the Expo and Millennium lines could each ultimately have a capacity of 25,700 passengers per hour per direction (pphpd) – similar to Toronto’s Yonge Subway current capacity of 28,000 pphpd, which will increase to 36,000 pphpd in the future largely from the switch to automation. Currently, the peak hour capacity of the Expo Line is 15,400 pphpd.

The Canada Line also uses SELTRAC but has a substantially limited capacity of 15,000 pphpd due to the usage of exceptionally short platforms and trains that are half the length of the other two lines.


Relatively short trains and platforms, which initially cost less to obtain and construct, can be optimally utilized with full automation technology. For example, instead of a 12-car manually driven train coming every nine minutes a four-car driverless train arrives every three minutes.

While high frequencies can also be achieved for systems that require drivers, the main difference revolves around automation’s relatively low operating cost.

Contrast this with the frequency levels of Seattle’s manually driven Central Link Light Rail, which operates at frequencies of no greater than six minutes during the morning and evening rush hour periods and 10 to 15 minutes during the rest of the day.

In Melbourne, trains on most lines arrive every 10 minutes during peak hours and nearly half of the lines see frequencies of 15 to 20 minutes on weekday off-peak periods. On weekends, trains arrive once every 30 to 40 minutes.

Automation technology allows SkyTrain to operate with the same high frequencies experienced in big metropolitan areas like Hong Kong and London, major cities that rely on population density and critical mass to support the frequent operation of major transit services.

Secondly, the Expo and Millennium lines utilize linear propulsion technology. A continuous rail strip of magnets are installed in the middle of the guideway of both lines between the rail tracks. The linear induction motors on the underside of each train use the magnets to propel the train, thereby significantly reducing the amount of moving parts found inside a train and the regular maintenance required.

Linear propulsion differs from conventional motors, the technology the Canada Line and most rail systems use – the same systems found in an electric automobile. Although the Canada Line is a part of TransLink’s SkyTrain system, the usage of conventional motors is the main technological difference with “SkyTrain technology”.

As well, linear propulsion offers superior acceleration and deceleration and can climb steeper slopes than conventional motors. Linear induction motors can climb grades of up to five per cent whereas conventional motors can climb grades of up to three per cent.

Overall, SkyTrain has an impressive on-time reliability performance of 95 per cent – a level that is higher that most systems of comparable size.

3. The technology’s future is not ‘up in the air’

Automation and linear induction motor technologies are the future of public transit, and Vancouver’s system is the pioneer of its application for an entire major regional rail transit system.

Other extensive systems that use full driverless automation technology include (this list does not include partial automation systems):

  • Barcelona Metro Lines 9 and 10
  • Beijing Line 4 Subway and Yanfang Line
  • Brescia Metro
  • Budapest Metro Line 4
  • Busan Subway Line 4
  • Copenhagen Metro Lines 1 and 2
  • Daegu Metro Line 3
  • Dubai Metro
  • Hong Kong MTR Disneyland Resort Line
  • Hyderabad Metro Rail
  • Incheon Line 2 Subway
  • Istanbul Metro Line M4
  • Kuala Lumpur Rapid Rail
  • Las Vegas Monorail
  • Lausanne Metro Line M2
  • Lille Metro
  • London Docklands Railway
  • Lyon Metro Line D
  • Milan Metro Line 5
  • Nagoya Linimo
  • New York City IRT Flushing Line and BMT Canarsie Line
  • Nuremburg U-Bahn Line’s U2, U3 and U21
  • Paris Metro Lines 1, 14 and 15
  • Rennes Metro
  • Rome Metro Line C
  • Sao Paulo Metro
  • Seoul Shinbundang Line
  • Shanghai Metro Line 10
  • Singapore MRT and LRT
  • Tokyo Yurikamome and Nippori-Toneri Liner
  • Toulouse Metro
  • Turin Metro Line 1
  • Uijeongbu Line
  • Yokohama Kanazawa Seaside Line

Other extensive systems that use linear propulsion technology include:

  • Guangzhou Metro Lines 4, 5, and 6
  • Osaka Imazatosuji Line and Nagahori Tsurumi-ryokuchi Line
  • Sendai Subway Tozai Line
  • Tokyo Toei Oedo Line
  • Yokohama Green Line

Other extensive systems that use both fully automated and linear propulsion technologies include:

  • Beijing Airport Express
  • Fukuoka Nanakuma Line
  • Kuala Lumpur Kelana Jaya Line
  • New York Air Train JFK
  • Scarborough RT
  • Yongin Everline

Many of these systems were built over the last ten years, and several are under construction.

Various companies offer automatic train control systems and the same can be said for trains with linear induction motors, namely Bombardier and Japan’s Kawasaki Heavy Industries.


But Bombardier is of course the preferred supplier for TransLink and other Canadian transit operators due to senior government pressures, sometimes through incentives and funding stipulations, to invest in the national economy and keep jobs in Canada.

A recent local report highlighted the woes with the Scarborough RT system, which uses the same linear propulsion system with Bombardier/ICTS Mark I trains and is built with fully driverless automatic control.

But local critics of SkyTrain did not acknowledge that the Scarborough RT’s full automation potential is crippled by the usage of drivers due to union labour regulations. The Toronto Transit Commission (TTC) is also not able to order new and larger replacement trains – the Mark II and Mark III trains – due to a tight section of the elevated guideway that can only accommodate the turning radius of the shorter Mark I  trains.

Since it opened in 1985, the Scarborough RT has operated exclusively on the original Mark I  trains and little has changed to the system. The cost to upgrades the line to accommodate new generation trains was pegged at $360 million in 2006 dollars.

Despite the neglect, the Scarborough RT is the TTC’s best performing transit service.

“Notwithstanding criticisms and misinformation over the years, the Scarborough RT has been the single most-reliable service operated by the TTC,” reads a January 2013 report by the TTC. “The service has been very successful at attracting ridership and has been operating over-capacity for a decade.”

4. The alternatives aren’t pretty

While there are some corridors where ground-level light rail is suitable, in most proposed applications light rail options are inferior to SkyTrain when a cost-benefit analysis is presented.

Fully-grade separated systems, like an extension of SkyTrain, are needed for the Broadway Corridor and Surrey in order for transit to meet the present and future ridership and capacity needs of the region’s vital corridors and population centres.

Surface light rail is generally slower than SkyTrain given that it is usually manually driven and requires long interrupted stretches to achieve its maximum design speeds and capacity. While this is possible for the Arbutus Corridor, the same cannot be said for Broadway.

A light rail line running on the street level on Broadway would essentially create a physical barrier in the city while significantly reducing the capacity of one of Vancouver’s main east-west arterial streets.

For light rail to achieve a 30-minute travel time from the SkyTrain terminus to UBC, 62 of the 67 intersections along Broadway would have turn restrictions resulting in diverted traffic. On the other hand, an underground SkyTrain will achieve the same route within 20 minutes.


For the same reasons, the provincial government axed a light rail plan for the Evergreen Line and resurrected the original SkyTrain extension plan for the route. A business case report revealed SkyTrain would cost $1.4 billion, just $150 million more than light rail while also providing a far greater capacity, a higher service frequency, lower operational costs, and a convenient, transferless “one-train ride” to Vancouver.

The Evergreen Line’s light rail option uses the same route used by the SkyTrain option, including the need for the same 2.2-kilometre bored tunnel. Light rail would take 25 minutes, but SkyTrain gets there in 15 minutes.

As well, light rail systems that run through streets and intersections are prone to collisions with vehicles. And when this occurs, it cuts down service reliability significantly.

A business case on Surrey light rail transit could have similar findings that recommend SkyTrain over surface light rail.

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5. Synergies and economies of scale

There are major operational savings by building a seamless network that utilizes the same train fleet, infrastructure and personnel. At the same time, the limitation of ‘unnecessary’ transfers reduces travel time and in turn attracts greater ridership.

When the Millennium Line is extended to UBC, transit users will be able to take a seamless one-train ride from the Point Grey campus to Coquitlam Centre in under one hour.

DH Vancouver StaffDH Vancouver Staff

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