From the Red Line
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From the Red Line

The CRL is genuinely hard

But can we get it done in just under 10 years?

I’ve spilled a lot of ink on how we should try to get back on track with our political targets of 360km of rail by 2030. The CRL will be playing a very large role in that.

At the same time, though, I have to recognize that building the CRL is going to be a complex undertaking. At best, one may be able to wring out only a few months of acceleration at most, even though one might have to find ways to save years with the least charitable interpretation of “early 2030s” being the end of 2033. With the CRL not yet under construction, there’s still a real risk of some surprises during the construction phase which could lead to us missing that goal, too.

In my opinion, if we’re going to spend money on acceleration works, we might as well see how much more benefit we can extract from the line to make that additional investment worth it. The Arup Journal 2006/3, detailing the construction of the KCR West Rail Line, may be a good reference, even though its main focus is on noise abatement issues and so potentially more relevant for the JRL.

Follow the money

The recent Budget announcement that the government is once again willing to take out infrastructure loans may solve the foremost problem; a lack of money that requires projects to be broken up into phases as well, in order to smoothen the curve and manage the amount of money that has to be paid out every year.

It’s easy to fall into the trap of whether this means faster completion time for projects. Yes, $90 billion is a lot of money. But there are other things fighting for a share of the pie as well, such as housing, the Tuas Port, and airport expansion. Sure, it might make it more plausible to ask for more money in order to throw more people at the works and rush our railway development, and that’s a promising development. But I’m me; I like to see the negatives in everything.

So the construction of new lines is not the only issue. We also need to take care of our existing network as well, which while may not necessarily qualify for loans, it will take up time and attention as well. It would not make sense to repeat the mistakes of the 2000s with LTA distracted with system expansion and allowing the existing network to decay because operators have other concerns to worry about.

Thus, while the ability to take loans will help and possibly get us a year or two back, it’s not something that we might be able to use for its full potential even if rail expansion is given priority access to such funds. Of course, this may be the start of a larger debate about the LTA’s role and to what degree of involvement it has in operating lines, but that’s probably for another day.

A further concern might be the time needed for land acquisition. On state land, the bulldozers can move in pretty quickly (such as with the RTS), but you need time to buy out private property owners and/or arrange compensation. Such processes take time, and while it would be fair to presume that care is taken to minimize land acquisition, it not only poses a financial cost, but also a time cost.

The great reset

We also should firstly consider the strategic goals of the CRL and how well it’s meeting them. If not, it may be a good idea to take advantage of the current situation not merely to sit on our hands, but to revisit the CRL plans and see how they can be improved.

The CRL has three major stretches of long tunnel — under Changi Airport, under Paya Lebar Air Base, and under the CCNR, with the last also being the most controversial. We’ll just look at the last one since there’s some math to back up our numbers there.

Under the direct alignment, the CCNR tunnel is expected to be around 4km long; while it’s 9km long under the skirting alignment. This additional 5km will supposedly take 6 minutes to traverse, a speed which I would put on par with the existing NSL between Yio Chu Kang and Khatib where trains travel at 80kph. At the end of the day, compared to the former KCR lines or the Taoyuan Airport MRT, both of which have long segments in the middle of nowhere as well where speeds of 100kph or greater are achieved, this isn’t a very good look for us, and a very big missed opportunity to significantly improve the transportation landscape — even if the high speeds are only achieved in the long tunnels and not on AMK Avenue 3.

Would it be a good idea to make the CRL trains even faster? I don’t know. On one hand, faster trains produce more vibration, which is a concern for the wildlife and biodiversity within the CCNR; even if this may apply less to the fast stretches under the airport and perhaps PLAB; even so, there are always ways to mitigate this. On the other hand, the travel time improvements from faster trains on long nonstop stretches would result in both productivity improvements by people spending less time travelling, as well as a higher pull factor to take the CRL over existing lines for long cross country trips.

I get that this last bit might regress into some scary short term thinking and ignore the potentially different environments around quite a few stations that may exist when the line opens in the early 2030s. It’s also something that might not appear immediately relevant, seeing as the CRL runs through areas that already have some form of train service, with 6 out of 15 CRL1/Punggol branch stations being interchanges and there possibly being at least 3 more interchanges between Bright Hill and Jurong Gateway.

With the recent furore around Clementi Forest calling for the preservation of the forest, and similar calls for the area around Dover station, it makes one wonder more about the likelihood of a potential CRL station in the area. The same may be said about PLAB and the Lorong Halus stretch between Elias and Riviera too, but we know that for now, there’s only plain tunnel through those areas — stations, if any, will probably only come much later.

Perhaps one could also apply such thinking to Turf City, but considering the principle of first do no harm, there’s not a lot more harm one could do given how most of the land is already cleared. Sure, you could allow it to return to wilderness, but what’s the point when the land is going to be cleared again in 20 years anyway? In short, putting some stations on hold and tweaking the design to allow higher speeds to be achieved in the absence of said stations may help, if you ask me, but the need to develop the land (and justify stations) will need to be weighed.

As always, read the fine print

I’m no geotechnical expert, but that said, I’d think that the tunnels really can’t be built any faster. Due to environmental concerns — all the more relevant these days with society somehow having a renewed interest in ecological preservation — launch shafts in the middle of these tunnels are out of the question, so we work on the assumption that one machine would have to drive all the way.

As the CRL is widely expected to cross the DTL in the area of King Albert Park station, perhaps a comparative example could be used in the form of the construction of the DTL2 tunnels. Even after subtracting away a few months of doing nothing while the Alpine bankruptcy was dealt with, it still took around a year to dig the 1.3km of tunnels from King Albert Park to 6th Avenue. 4km of tunnels could be three times that, so three years but that’s with significant margins of error due to varying ground conditions that could permit high speed one day and bog down the TBM the next. This, I guess, also lines up with the SMART tunnel in KL, of similar specifications.

While a single large TBM could start digging within three months after contract award, made possible by having the TBM launch shaft be built by the the contractor building CRL Bright Hill station, this may be an unrealistic expectation given the need to actually manufacture the TBM, a process which could take at least a year.

So even if further details of the project are announced in 2022 (and also already assuming the contract can be awarded within the year), and the TBM is launched in 2023, we’re still talking about the TBM finishing its work only in 2026 or 2027 at the earliest —and thus, systems installation and testing works would make the end of 2030 a very optimistic deadline. (EDIT: I found a number to back up my claims — the CCNR EIA states that it would probably take 5.5 years just to construct the tunnel — starting next year, the tunnel would probably only be ready in 2027 at the earliest)

Another time issue may be deep stations, with possibly at least one at Hougang and maybe another at Clementi in order to allow the tunnels to go under the HDB blocks adjacent to the stations. Deep stations pose a fair bit of problems related to transfers — I’d expect the latter to look like Jingan station in Taipei, with at least 10 floors between the Circular and Orange line platforms. Yet, moving them is out of the question given the strategic connections offered with the NEL and EWL respectively.

Even if effort is made to reduce the footprint of the stations by using vertical space that would be dug out anyway for cut and cover excavation, there would still be significant actual volume to be dug, which is always going to be a problem time-wise unless some hyper-efficient excavation technique can be developed in order to make the station faster to build. Though that still doesn’t answer the question of other support activities, such as truck movement to remove the excavated material from the site, which will also need to be arranged such that disruption to the area is inconvenienced.

Left out of the fun?

One thing is for sure — there are several large groups of Circle Line passengers who will still continue to take the Circle Line even after the full completion of the CRL, such as those working in the industrial estates in the MacPherson area which the CRL completely bypasses.

Under the old regime where each line is evaluated by itself without thought for the network effect, it would have been quite difficult to justify building a line like the CRL, which already functionally acts like an express service. The only confirmed new growth areas it connects are in the areas of Tampines North and Turf City. While sure, the AMK Avenue 3 stretch could see some densification, there’s not a lot one might be able to do given the height limits posed by aerodromes in the area.

But some haste with the CRL can still help these people — by taking away a majority of the passengers who would need to travel relatively long distances along the EWL and CCL, we can hope, possibly, to reduce the demand along those lines early enough before it builds back up. We may have bought ourselves some time with the cancellation of the HSR and subsequently, some of the assumptions behind JLD no longer holding true, but an alternative that’s substantially compelling time-wise, apart from getting downstream passengers may even inspire reverse-commutes of some form, where passengers go against the generally accepted peak flow.

I say this, though, but it may be difficult to predict exactly what will happen. It may just so happen that in the new world, with workplaces scattered all over, people just do that anyway, in which case we’d still need that additional capacity.



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