The ideal medium-capacity train

From the Red Line
Published in
9 min readFeb 17, 2024


Futureproofing means throwing out everything we’re used to.

A while back, Taipei Metro revealed the Alstom train design that will be used on the next phases of their Circular Line. I can’t help but think that it may be overdue for us to review how we design our trains too, especially for the medium-capacity lines.

In fact, many of our rolling stock design challenges may be very similar to Taipei’s, with many (relatively) sharp curves along the Circle line alignment.

While it is too late for the C851E trains, I hope that the LTA can take these points into consideration when they start planning for the replacement of the Circle Line fleet. Of course, this could be a bit premature ourselves, considering that we are not likely to be buying those trains within the next 10 years, but it’s probably worth noting down for posterity anyway.

Some ideas can even be tried out at the SRTC, with plenty of time to go before the current CCL trains need to be retired. 10 years should be plenty of time for the LTA’s engineers to convince themselves if these solutions can work.

Problems needing solutions

I’ll probably want to start here because this is probably the most immediate issue. It’s not as crazy as it sounds.

A Zaobao article from not too long ago actually named the Circle and Downtown lines as some of the largest culprits of train noise.

While all still largely within the limit of 85dB, there are some parts that some might argue produce a noticeable difference compared to older lines. Especially on the Circle Line, which has an alignment that takes it under buildings and snaking through estates — an alignment impossible to build aboveground, and which has far more twists and turns than any MRT line before it.

Worse, some sections of track cause wheel wear, which eventually affects the whole line. This may well be the main issue with the TEL as it stands. No one wants to see trains slowed down, but if it has to be done, then it must be done. As I saw in Taiwan, the tunnels between Dongmen and Chiang Kai-shek Memorial Hall on Taipei Metro’s Xinyi Line do that, with a minimum of 200m radius in the Xinyi Line tunnels. Hear it for yourself below.

not my video

The sharpest curve in Singapore is even sharper than that, being the 140m radius curve that allows trains from the Dhoby Ghaut branch to access Promenade station. Well, one option is to find a way to get rid of that branch. But if we can’t do that, then we might have to mitigate its effect, both the sharp curves itself, as well as the excessive wear that it causes on train wheels that then wear down other parts of track along the line.

EDIT: Citation here (source: URA SPACE)

With a bogie wheelbase of 2.3m on Taipei’s C301 and C381 trains, their trains are easily more maneuverable and friendly to sharp curves than our MRT trains, which have a bogie wheelbase of 2.5m. The Toronto Rocket trains, which are only slightly narrower than our heavy-capacity MRT trains, also only have a bogie wheelbase of just under 2.1m, permitting them to take curves as small as 75 metres radius.

Likewise, one of the key changes needed to fit the JRL into the built-up Boon Lay and CCK areas is that they had to use smaller trains — 18.6m by 2.75m — and I won’t be surprised if the bogie wheelbase has to shrink accordingly, considering the tight 100m radius curves. Flexibility is key, that might be a thing. On the JRL there may be other track technologies that can help keep out external noise too.

But as my experience in Taipei shows, the fact that the JRL is elevated may complicate even further the LTA’s ability to keep wheel wear — and by extension noise — under control. Though I suppose that if the need ever comes to replace bogies before the train car body, the LTA can possibly consider this.

Tokyo Metro also uses steerable bogies on their Ginza Line 1000 series and Hibiya Line 13000 series trains — on the Ginza Line, to manage noise around curves; and on the Hibiya Line, to permit longer train cars to fit into the line. By reducing the angle of attack between the wheel and the rail, the trains can thus be quieter.

Another approach

I can’t help but wonder whether a more nimble train, along the lines of the JRL trains, can help to also improve curving performance along the rest of the line and potentially allow for some speed limits to be increased — decreasing journey times too.

screeeeeech (source: OneMap)

This can include areas such as those around Farrer Road or Serangoon on the Circle line, and around Mattar on the Downtown line. Many of these aren’t the end of the world per se — they may still be within the 300m radius allowed by the LTA’s engineering guidelines — but speed restrictions are generally imposed around such curves, perhaps which any OpenBVE player might be aware of. Many of these restrictions are part of why the Circle Line is the slowest MRT line.

Thus, apart from reviewing the design of the bogies, the LTA could well consider reviewing the entire parameters of the train itself. More, but shorter cars, could be one way to make the entire train more maneuverable, and perhaps help to counteract the impact of leaving so much space between cars for the gangways anyway. Perhaps gangways can also be shortened and car bodies expanded into the space; like how Taipei’s gangways are smaller than Singapore’s.

Shorter cars could also provide an opportunity to lengthen trains without extending platforms, by giving us space to extend the space between the ends of the train and the first/last doors. There may be some train control equipment modifications needed, like what Vancouver’s doing for their 5-car Mark V trains, but it’s still going to be lesser than the issue of hacking walls and installing more platform doors.

On the train, this may be similar to London’s deep level tube trains, or those used on Guangzhou Metro lines 18/22. More seating can then be installed in this area, much like the upper deck of a double decker bus, to compensate for seating removals near the middle of the train.

Guangzhou Line 18 train — extra window spacing between cab and first passenger doors (source: TONY LU, Wikimedia Commons)

I will take a while here to explain why the typical opinion of “just add one more car lmao” will not work. Hong Kong already does that, when it runs extra trains using the Tung Chung Line fleet to quickly get passengers out of AsiaWorld-Expo station on the Airport Express. Since the 8th car aligns with the loading doors for the Airport Express’ baggage cars, all doors on that car are locked, and passengers alighting must head back to the 7th car.

This adds time, and thus, there are stickers in the train tell people going to Hong Kong station to move to the 8th car, so they don’t have to fight their way out at Kowloon or Tsing Yi. It appears to have mixed results, where passengers appear to prefer to remain in the more accessible 7th car. A few metres and a few rows of seats may still be acceptable, but a whole car worth would take far too long to load and unload, and may actually be more counterproductive than just running more trains to make up for the missing car.

It’s also useful to note that London also tried this briefly on the Northern Line before the Second World War, but abandoned the practice during the war. Today, instead of trying the idea again, the Northern Line tries to squeeze as many trains as possible, using the same Seltrac system as us, to transport as many passengers as possible.

Either way, if changes are made to the train configuration, depots must be upgraded. How this can be done without affecting service capability or reliability, remains to be seen.

The things that don’t need to be said

Of course, these trains should also be including features that come as standard on almost all new trains, such as LCD displays showing the next station and the route the train is taking — all the more important on the Circle line. In fact, it may even be necessary on the Punggol LRT too.

A particularly silly thing that has been done on the shuttle service between Labrador Park and HarbourFront has been the use of hard signage, flipped by the crowd control people on site to show the direction of the next train. Another thing worth learning from Taipei is to install outward-facing indicators on the sides of the train to show the destination of the train. It would have been useful for this case, but even after CCL6 is complete, it can still be useful to show passengers on the platform where the next train is going, in addition to the arrival screens.

Wider doors should also come as standard. At the very least, I would expect the 1.5m wide doors as used on the JRL. But there could be space for going even wider —it appears that the Kelana Jaya Line trains in Kuala Lumpur have a train door width of 1.6m; their platform doors only 1.8m wide, same as us. The Paris Metro has even wider train doors — at up to 1.65m for the MP 05.

However, it goes to say that the Mark III and Paris Metro trains are likely able to stop more accurately, and control systems improvements may need to be pursued here in order to achieve the same level of accuracy. This was a challenge for MTR in installing half-height gates on the Ma On Shan line back in 2017. But today, advancements in control systems should make this possible, though even if it isn’t, there may be a possibility to accept the reduced effective door width, depending on the system performance.

It can also be considered to reconfigure trains to maximise the amount of overall space that will be used by passengers, and considering that a majority of Singaporeans don’t move to the center of the train car anyway. Taipei Metro trains already provide some bus-like cross seating between train doors.

And on one of their new train cars, BART went from this to this, with a similar amount of space available between doors as us, at around 17 feet 5 inches (around 5.3m).

If lesser people want to stand in the area between train doors, might as well let them sit.

And of course, I can’t help but notice that equipment lockers on trains are getting bigger. On older trains, the lockers were only deep enough to house a fire extinguisher. Even on the DTL trains, they may have been able to place the 2-seaters back, since the wheelchair space is located on the car end. But on newer R151 trains, it’s easily much wider than that; a larger fire extinguisher and then some. The wheelchair space has also been moved next to the windows probably because of this lack of space, much like on Alstom Metropolis trains. Doing something about that to reclaim passenger space may be necessary.

What can be done now

It does also make me wonder whether a different wheel profile could already also help to reduce wheel wear across the twists and turns of the Circle Line and perhaps the TEL too, compared to the relatively straight 6-car lines that came before it. This can perhaps be a quicker move compared to having to design a totally new train or replace bogies at great cost; while not a final solution, it can be a quick win.

I would not be surprised if wheel wear was the root cause of the cracked rail at the Promenade junction on the 29th of September 2023, which resulted in what may easily be one of the longest disruptions in MRT history; the Circle Line having to single-track from Dhoby Ghaut to Stadium for 17 (seventeen) hours while the cracked junction rail was repaired.

In BART’s case, wheel profiles are also the cause of why the Transbay Tube is so noisy, and an adjustment by Bombardier allowed noise levels to drop drastically even on the older trains. Similarly, for what cannot be prevented, BART has micro-plug doors to mitigate their effects; so do the CRRC-built Ampang/Sri Petaling AMY sets in KL. These are examples of what might be worth studying.

The $600 million SRTC can be used to evaluate engineering changes that ultimately benefit commuters by improving capacity and comfort. Whilst we may not be able to invent many new rail innovations, the onus is on the LTA to be able to integrate ideas from the worldwide rail industry at large and convince themselves that these ideas can be applied in the Singapore environment.

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From the Red Line

Sometimes I am who I am, but sometimes I am not who I am not.