Everyone should know about the fiasco going on about Communications-Based Train Control, or CBTC in short, that’s currently being on full-day trial on the North-South Line, and in normal operations on the Tuas West Extension.
On the Tuas West Extension, we couldn’t say much because it’s built with the new signalling equipment, without the old ones supplied by Westinghouse. (Which is basically now under Siemens.) However, we will talk about the Tuas West Extension later in the article. For now, let’s focus more on the North-South Line, as it serves basically more than 20% of the nation that’s living in the north (Yishun, Sembawang, Woodlands, Choa Chu Kang).
Thales SelTrac CBTC vs Westinghouse
What is the difference between CBTC and Westinghouse anyway?
The new CBTC signalling allows the trains to run at much shorter frequencies at 100 second intervals instead of 120 second intervals with the old Westinghouse signalling system.
It doesn’t sound as much when put into numbers, but it can greatly increase the amount of trains per hour by a significant amount. As the old system has been serving for over 30 years, a signalling change is required to replace the old system which could get more costly to maintain over time.
The two signalling systems operate quite differently as well. Imagine a straight one-lane road, with two traffic lights in-between.
Under Westinghouse, only one car can occupy a stretch of road between two traffic lights at any given time.
Whereas under CBTC, multiple cars can occupy that same stretch of road between the same two traffic lights at any given time.
The new system allows the Operations Control Centre (OCC) to identify the exact location of the train itself as well, whereas the old system only allowed them to know whether the stretch of tracks (usually between 800m to 1000m) is occupied, or not.
The North-South Line
Here’s a short timeline to recap about the commence of CBTC:
- 4 December 2015 – 91% of North-South Line Re-signalling Installed.
- 17 October 2016 – 98% of North-South Line Re-signalling Installed.
- 28 March 2017 – Last hour operations commenced.
- 16 April 2017 – Full Day operations during Sundays commenced.
- 29 May 2017 – Full Day operations commenced.
That’s the five main dates you’ll remember. In the chart in the first two links, you may be wondering why does it take 10+ months to complete just 7% of the re-signalling project?
My guess is probably just installation in Bishan Depot, and perhaps tests that were carried out as well. But you have to note that they are more dominantly occupied by the track sleeper replacement project that is prioritised over the re-signalling project. Why? Because residents kept complaining about the large amount of noise levels during late night.
However, another thing that baffles me is that they shifted from the last-hour operations to full Sunday operations in just 19 days of testing, which roughly equates to 19 hours or less of passenger hour testing. (They did not use the system when there’s train service extensions on public holiday eves.).
Alright, then let me list the incidents that occured between 28 Mar and 16 Apr along the North-South Line.
Alright, so neither of those two faults were related to the new signalling as both did not occur during CBTC operations.
So let us look to the next period: Full Day operations during Sundays.
Seems good, no major faults reported during CBTC operations. But little did they know…
Alright. Time for the finale: The Full Day Trial.
- 1 June 2017 – Signalling System Checks. – 1847hrs
- 2 June 2017 – Signalling Fault. – 1750hrs
- 12 June 2017 – Signalling System Fault. – 2110hrs
- 28 June 2017 – Signalling System Failure. – 1715hrs
- 29 June 2017 – Signalling Fault and Platform Door Fault. – 0640hrs & 0820hrs
Wow. What the heck happened?
Most people would’ve compared how terrible Land Transport Authority did to introduce the CBTC system to the grid as compared to how UK did it, with their Jubilee and Northern Lines both equipped with CBTC (TBTC on the Jubilee Line).
Admittedly…yes. I felt that Land Transport Authority did rush a bit, for a couple of reasons.
Here are some reasons why I think the faults were occurring on the North-South Line, and why LTA kept rushing the project.
- They already exceeded the deadline set back in 2012.
The original deadline for the new system to be fully implemented on the North-South Line is in 2016. However, sleeper replacement works took priority and hence the re-signalling project is delayed.
- They couldn’t wait to test the new C151B trains.
Dubbed the B-Trains, they came lavished in clean, white livery with 1 new feature which is STARiS v2.0, a.k.a. the TV screens you see on top of every door. Manufactured in China by Kawasaki and CRRC Qingdao Sifang Co, every aspect of the train is exactly the same as their C151A counterparts that were already in service in 2011. But what makes them different is that they do not come installed with the Westinghouse signalling equipment. That’s right. It means these pretty new trains has been sleeping in the train depot for nearly over a year, unable to be put on service (or even on testing!) as none of the train lines were using CBTC.
- The diversity of the trains on the North-South Line.
This is more of a theory than something factual, I may be completely wrong, but I remembered LTA mentioned it somewhere. As the North-South Line have many different types of trains, and each train using a different (or same) traction motor, it requires time for the system to time the time required for that particular train to stop nicely in the station.
- The old Singaporean enemy: Rain.
In the UK, you don’t get as much rain as here in Singapore. When it rains, it pours here. The tracks get very slippery and as the system is fully automatic in the rain as well, something is bound to go wrong. I’ve heard many, MANY incidents of trains overrunning stations by a few doors during rainy weather. When a train overruns, it needs to reverse back into the station, costing precious time. The train frequencies therefore got bad (really, really bad) when the back trains begin to bunch. Take a look at this visualisation to how bunching can occur even with a small delay. Even though it’s about buses, the trains travel at the same speed and several factors such as passengers rushing last-minute into trains could potentially cause a ripple effect and cause a massive train bunch up.
- There are many bugs with the new system that are not fixed.
I have noticed several of these as well, and some goes from minor to even perhaps able to disrupt services. The most minor bug would be that the train doors and the Platform-Screen Doors would close simultaneously without any announcement. It may seem minor, but it could delay the train if there is… let’s say, a human sandwich, with the bread being the doors and the human being the meat. The doors are fully automatically controlled as well. The more breaking bug would be at Jurong East. I’ve seen it before, where the train would just casually coast over the crossover while the front train is still inside the station. The result is that the train need to reverse out of the crossover to allow the front train out of Jurong East. It becomes total gridlock if there’s massive bunching behind.
- It’s the holidays.
They could either wait until December or… June! Admittedly, they wanted to avoid having the system still be in testing phase when school reopens. However, implementing the new signalling system didn’t sound as good as it went, and the testing phase went right over the school opening. People were complaining, asking SMRT and LTA to conduct tests at night. However, residents would complain of loud noises and being unable to sleep at night, which already happened many times before. That is why they didn’t conduct intensive testing during off service hours. The trains need to undergo maintenance as well during non-revenue hours as well. Track maintenance is at high priority as well. They can’t keep testing the new signalling system to have you all complaining again because of track fault. The UK had a luxury of a period of time with reduced frequency train services, Singapore don’t.
- They could have needed Tuas Depot to free up space for more maintenance work on trains.
Tuas Depot is probably filled with more than 20 B-Trains when they were all delivered to Singapore. Most of the parking space is probably taken up by these dust-pickers which probably just slept inside the depot for nearly a year. Tuas Depot is said to be a major depot which maintenance and overhaul can be carried out in, aside from Bishan Depot. Freeing up a depot for more maintenance work could allow Bishan Depot to have lesser workload on maintenance and to focus more on Signalling checks, and fixing critical issues with the B-Trains, if one were to appear.
What could have been done better?
Well, as another 19-year-old had pointed out, make full use of shadow mode like what the Tube did with the Jubilee Line.
However, I am actually unsure if LTA/SMRT did perform a shadow mode with CBTC on the North-South Line. But looking at how bad things are going, either they tested it too little, or they did not test at all.
One key difference between Singapore and UK is that the CBTC in Singapore is 100% automatic – including door operations; whereas in the Tube, it’s manual even in Automatic. Hence the notices you see on the platforms regarding the automatic doors.
Some did point out they could have performed the signalling upgrade to the short Changi Airport Extension, but unfortunately as the 19-year-old (damn it!) had already pointed out, the depot is going to move to a newer facility, it is just a waste of money to install the new signalling inside the entire Changi Depot as well. Furthermore, delaying people on the way to catch their flights isn’t the best idea either.
Testing in phases really did seem to be the best choice in theory, however it would mean that the new B-Trains can’t be put on service. It’s very difficult to perform phase testing for North-South Line either as passenger demand for the entire line is quite high.
Hence that’s maybe the reason why LTA dove straight for full-line testing. I don’t really blame them either, just that they are too rushed and failed to properly educate the public.
Honestly, I don’t feel like being treated as a guinea pig, contrary to what people have been saying in various social medias. Not that I support LTA, but I just felt that suffering for this period of time may prove to be a huge improvement to the big latter part of your life.
One contingency plan they could have made in place is to deploy more Service Ambassadors at high-flow stations, and prepare buses and maybe ask SBS Transit to assist them to provide a train shuttle if the train line were to completely fail.
I felt like LTA could have done better in terms of communicating the possible train delays. Explaining to the public about the rush for new train system, DOs and DON’Ts need to be emphasised as well.
When there is a delay or fault, the issue needs to be immediately conveyed to all passengers and platform staff, and the general public as fast as possible.
If you can’t prevent an incident from occurring, make yourself shine by being the best at solving them.