Understanding of systems and operations crucial in finding out reason for Monday’s unprecedented incident
MONDAY’S incident involving the collision of two light rail transit (LRT) trains is unprecedented in almost 30 years of the system’s operation. A whopping 213 passengers were injured in that incident with 64 of them needing hospitalisation.
As with any accident of this magnitudeinvolving the carriage and injury of passengers, it will attract much attention and countless opinions and speculation.
It is, therefore, the responsibility of the investigators to detach themselves from the flow of speculative information and focus on the evidence and facts at hand, delving deep into the incident, inclusive of the history of the system and the competencies of the people who operate and maintain it.
Unfortunately, in cases such as this, the blame is pointed squarely at the driver as being the party at fault and therefore, he/she is guilty until proven innocent.
In reality, this is rarely the case that a single individual or event would have caused this type of accident.
To understand what went wrong, one must first understand the system, specifically the operational and safety aspects.
True driverless metro operations are defined as being GoA4 (Grade of Automation 4) systems, in which trains can operate fully automatically, including door closing, detecting obstacles, and responding correctly to emergencies etc.
There tends to be a public belief that driverless trains are a very recent development, but they were introduced in the 1980s. Since then, there has been an increasing public awareness of autonomous train operations, as a growing number of city networks embrace true driverless systems, with trains that run automatically with no need for any on-board staff.
In Malaysia, the Kelana Jaya LRT and MRT lines 1 and 2 are automatic systems that are managed from a control centre using remote technologies, such as CCTV cameras and on-board sensor technology.
The benefits of a driverless system are numerous. Where the significant benefits are is in its ability to provide increased line capacity. Driverless systems optimise the running time of trains and increase the average speed of the system, allowing trains to run more frequently. At the same time, reducing operation costs by controlled energy consumption, and allowing operators to optimise deployment of their resources.
Understandably, one key barrier to public acceptance is the perception that a train without a human driver is less safe.
Isolated cases have occurred in various places where the intervention of a human driver has prevented an accident, but on metro networks that have been specifically designed to host driverless trains, the evidence suggests that safety records are excellent.
Using a driverless signalling Communication-Based Train Control (CBTC) system, as well as a secure communication network for security and other subsystems, including public address and passenger information equipment, can fulfil the highest security and safety standards.
So, therefore, with a system that is specifically designed, tested and proven to avoid two trains coming into close proximity of each other, how was it possible to have the incident witnessed on the Kelana Jaya LRT line?
As with any incident, the chronology of events needs to be broken down into bite-sized fragments to enable one to start piecing together the events that led up to the two trains colliding. For ease of understanding, let’s look at the three primary facts that we know.
1. For one reason or another, one of the trains was being operated manually, either for fault recovery or testing (or for reasons unknown at this stage).
2. The other trains on the system were in normal operational mode, meaning these trains were operating automatically.
3. The two trains collided at speed, meaning the two trains were operating/moving in the same section of track.
From these facts, one can then ask the following questions, which should in part, or full, lead to an understanding of what contributed to this accident.
1. With a system designed to avoid trains to run in close proximity, why were there two trains on the same section of track? Knowing that the system was in normal operational mode (train carrying passengers), one can only assume that the system could not detect the manual driven train, thus being what’s called a “ghost train”, and so permitted the passenger train to enter the same section of track.
2. If the manual-driven train was indeed a ghost train, why was this the case? For a train to be undetected on a system designed to detect all trains, there are only two possibilities: 1) a system error and/or 2) the detection of the manual train was purposely (or intentionally) turned off.
3. The whole system, although automatic, is controlled and monitored by staff located in an Operations Control Centre (OCC). All changes, overrides and emergencies etc on the system are controlled and authorised by the OCC. One must then assume that the OCC had authorised the manual train driver to be in the system undetected.
Did the OCC approve this movement? Was the OCC monitoring the movement of the manual train? Were the OCC and driver of the manual train in communication with each other?
As can be determined, by just touching on the primary facts, it is clear that more than a single factor contributed to the incident, and while the blame points toward the driver, he/she maybe a victim to shortcomings of the operational procedures and/or technical systems that led to this unfortunate incident.
While the public and industry await the report from the investigation committee, we should all spare a thought for the innocent passengers, the real victims, and wish them a speedy and full recovery.
By : Mark Staib (Executive director of PETRA Transit Systems Sdn Bhd. He has more than 25 years of experience in the railway industry encompassing manufacturing, integration, and commissioning of all types of rolling stock and rail systems. Some of his noteworthy projects include the LRT (Malaysia, Ampang Line), EMU (Australia, Brisbane & Perth), and Monorail Projects including Kuala Lumpur (Malaysia), Mumbai (India), Sao Paulo (Brazil) and Manaus (Brazil) – THE VIBES