Singapore River to be diverted for MRT
tunnels
Published on Apr 28, 2012
Part of the Singapore River, the site of Singapore's earliest settlements, will be moved so that an MRT line can be built under
it. The construction site (above) is where the tunnel-boring machine will be launched. -- PHOTO: DESMOND LUI FOR
THE STRAITS TIMES
By Christopher Tan, Senior Correspondent
Part of the Singapore River, the site of Singapore's earliest settlements, will be moved so that an MRT line
can be built under it.
In the first undertaking of its kind, the Land Transport Authority (LTA) and Korean builder GS
Engineering & Construction will dig a bow-shaped canal to divert the river.
It will then clear the drained portion of age-old debris and fill it with a stabilising material before boring
two train tunnels under it.
RELATED LI NKS
Singapore River to be diverted for MRT tunnels -- ST ILLUSTRATION: LEE
The original path of the waterway will be reinstated after the tunnels are completed.
The nearby River Valley Road will also be moved temporarily to build the new Fort Canning station.
The project, which is part of the Downtown Line 3, is estimated to cost $255 million.
LTA senior project manager Chang Kin Boon said the site presented a unique challenge.
'The tunnels will be just 4m below the river bed, 5m away from the Central Expressway tunnels and right
in the middle of a heavily built-up area that is a tourist belt,' he said.
Although the LTA has diverted smaller waterways such as Kallang's Pelton Canal and the Rochor Canal,
these previous projects pale in comparison, it said.
LTA also said that it had considered many other alignments for the MRT tunnels before deciding on the
present one.
It had explored other methods of building the tunnels without having to divert the river. But these, LTA
said, proved to be too risky and environmentally unsafe.
LTA deputy director Indran Ratnam said the decision to reroute the river by building a canal was made
after'many, many meetings' with PUB.
PUB is the national water agency in charge of waterways.
Mr Chang said the river diversion will allow tour boats to carry on plying in the area during the three-year
construction period. 'It is the least disruptive method,' he noted.
Singapore River diversion a herculean task
Method the least risky one, with the least environmental impact
Published on Apr 28, 2012
The waterway diversion will see the Singapore River temporarily flowing through where the cranes now are, during works
for the Downtown Line project. -- PHOTO: DESMOND LUI FOR THE STRAITS TIMES
By Christopher Tan, Senior Correspondent
The plan to divert the Singapore River may be the most ambitious part of the MRT Downtown Line
project.
The herculean task, to begin by the end of the third quarter, will reroute part of the river next to Riverside
Point into a bow-shaped canal.
River Valley Road will also be altered to build the new Fort Canning station beneath it.
B ACKGROUND STORY
Other challenges of Downtown Line
CONSTRUCTION of the $12 billion, 42km Downtown Line is fraught with engineering challenges.
Besides the Fort Canning project, which involves moving part of the Singapore River, here are some other factors that keep
the project's engineers awake at night:
 Building the Telok Ayer station (Downtown Line 1) in a densely built-up part of the business district involved erecting a
two-lane, 400m viaduct to divert traffic from the construction site.
Downtown Line 1 is almost complete and the viaduct has been removed.
The Telok Ayer tunnels also crossed over the existing East-West Line tunnels. The space between them is only 70cm.
 Downtown Line 2, along the Bukit Timah corridor, runs through mixed soil conditions, which has slowed progress.
The top layer is mainly soil of varying thickness, and there are several huge boulders along the way. Blasting is required to
remove them to make excavation work easier. In rocky terrain, this can take twice as long as in pure soil.
The construction teams have had to use extra boring rigs, cutters and cranes to keep to schedule.
 Construction of Rochor and Little India stations (Downtown Line 2) involves going through a densely developed area with
heavy traffic and a canal.
The Land Transport Authority (LTA) has planned more than 20 stages of road diversions and six stages of canal diversions.
 Bencoolen station (Downtown Line 3) is the deepest of all the MRT stations, going 43m below ground. Again, the work is
done in a heavily built-up area.
To facilitate construction, a stretch of Bencoolen Street between Prinsep Link and Bras Basah Road is closed to traffic until
the end of next year. This is the first time a major arterial road has been closed for MRT works.
The river is being moved so that the Land Transport Authority (LTA) can bore two train tunnels under it
for the Downtown Line 3.
Although the transport agency has diverted smaller waterways before, this is the first time it will attempt to
change the course of a river for an MRT project.
The $255 million project will not be easy.
LTA senior project manager Chang Kin Boon told The Straits Times that the tunnels will be close to the
river bed, the Central Expressway (CTE), and 'right in the middle of a heavily built-up area that is a tourist
belt'.
To complicate matters, the river bed may be littered with debris such as timber beams and boat anchors.
Besides warehouses by the banks, the area, home to Singapore's earliest settlements, also had a boatbuilding trade.
It does not help that the 126-year-old Ord Bridge is just next to the site as well.
The river diversion will take the form of a canal 8m deep, 42m wide and about 150m long.
It will start near the Ord Bridge and end above a portion of the CTE tunnels.
Once the river is diverted, LTA - with its Korean builder GS Engineering & Construction - will first fill the
drained portion with soil.
The project team will then clear the path of all obstructions.
This involves digging some 830 bore holes each measuring 1.8m wide.
After the obstructions are cleared, the area is filled with a stabilising material, before tunnelling.
The tunnelling is expected to start in the middle of next year, and finish by end-2014.
After the tunnels are done, the river will be put back on its original path.
LTA has previously diverted smaller waterways such as Kallang's Pelton Canal for the Kallang-Paya Lebar
Expressway, and Rochor Canal for another portion of the Downtown Line. But none has been as large as
the Singapore River.
LTA deputy director Indran Ratnam said: 'Those were canals, this is a river. And it's a reservoir.'
Mr Ratnam revealed that the LTA had considered 20 other alignments for the MRT tunnels, which would
link the Chinatown and Bencoolen stations in the Central Business District.
It had also explored other methods to avoid moving the river, such as using liquid nitrogen to freeze the
wet soil below the river bed to stabilise it before tunnelling, said Mr Ratnam.
Another was the more conventional way of damming up a section of the river before excavating across it the way the CTE tunnels were built.
Although the latter method would be more straightforward, Mr Ratnam said that the final decision came
down to which approach would be the least risky, and have the least environmental impact.
He added that because of the historical significance of the site, the project will account for archaeological
artefacts found in the excavation process.
'If the contractor unearths anything of value, it has to hand it over to us,' he said.
The diversion of River Valley Road will see traffic being detoured to the fringe of Fort Canning Park from
the end of this year. The road will be reinstated to its original alignment by end-2014.
The 21km Downtown Line 3 has 16 stations stretching from Fort Canning in the south to Expo station in
the north-east.
It has interchanges at MacPherson, Tampines and Expo stations and is scheduled for completion in 2017.
Train commuters waited 2 hours for shuttle
buses
Some buses went to wrong bus stop and some skipped stations
Published on MRT BREAKDOWNS COI
SMRT service operations manager Anbazagan Manickam said at one point on Dec 15, almost 700 people were waiting at the
bus stop for the free buses. -- ST PHOTOS: WONG KWAI CHOW
By Maria Almenoar & Royston Sim
When the train service broke down last December, some commuters waited for almost two hours before
the first of the free shuttle buses arrived.
Even then, it was far from smooth sailing. Some buses went to the wrong bus stop while others skipped
stations.
The bus bridging service to ferry commuters during MRT disruptions came under the spotlight on Friday,
when four service operations managers gave their accounts of what happened on Dec 15.
It was Day 10 of the public inquiry into the train disruptions on Dec 15 and 17 that affected more than
220,000 commuters on the North-South Line.
The Committee of Inquiry (COI) heard that some vehicles from the SMRT bus division were nowhere in
sight for almost two hours despite station staff being told by the Operations Control Centre (OCC) that
they had been activated.
Mr Anbazagan Manickam, 49, a service operations manager recalled for duty at Bishan station, said that at
one point, almost 700 people were waiting at the bus stop.
People were spilling onto the bus bays and, at times, onto the road. Police officers and SMRT staff had to
direct them back onto the pavement.
He added that when the first bus arrived, it came in a convoy of 10.
His counterpart at Novena station, Mr Chia Pen Chuen, 52, faced a similarly disorganised situation.
He said the buses initially drove past his station.
The swelling crowd spilled onto the bus bay and filled the spaces outside restaurants along the street.
He called for more shuttle buses while urging commuters to take the southbound line which had resumed
operations an hour and 45 minutes after the breakdown.
The buses finally arrived at the Novena bus bridging point after 9pm, about two hours after the first train
broke down.
Mr Chia told Chief District Judge Tan Siong Thye, who heads the three-man COI, that the station staff did
not have direct contact with SMRT's bus operations division. They went through deputy director of station
operations Teo Wee Kiat to inform the bus operations division that the buses were late.
Mr Lee Wan Seng, also a service operations manager, was asked by Judge Tan if it would be useful for
them to have direct contact with the division.
Mr Lee, 56, said: 'In this case, with so many stations involved, I think if everyone calls the person in
charge, it might be quite messy.'
At Orchard station, three to four buses at one point were waiting at the wrong bus stop, said service
operations manager Tan Pheng Foong, 51.
He directed a colleague to tell the bus drivers to stay put while he took commuters to the buses.
The committee asked the service operations managers if they knew what caused the delay in bus arrivals.
The managers replied that bus operations were under the purview of the bus division.
Train service controller Yong Pui Ng, 56, tasked with taking charge of disseminating information on Dec
15, said the Urgent Messaging System broke down when he was sending his third message.
The system allows the control centre to send messages to computers at the train stations.
In the past two weeks, the issue of staff training at SMRT has been raised.
And on Friday, its lawyer, Senior Counsel Cavinder Bull, submitted six bundles of documents to the
committee. These were on the type and frequency of training that station and train officers go through. He
said SMRT had a 'proper and thorough' training programme for staff but it 'can always be improved'.