Rail claws on older MRT lines likely to be
replaced
All 30,000 metal claws holding the power-supplying 'third rail'
on the North-South and East-West MRT lines are likely to be
replaced, in what appears to be a further step to prevent
breakdowns in train services.
The Straits Times understands that rail operator SMRT has
started sourcing for new-generation 'positive lock' claws. These
can be bolted onto the rail sleepers - structures that support the
track - and are far less likely to be undone by vibration over
time.
Currently, the claws on the two ageing lines are not bolted but
are merely held in place by the weight of the 'third rail', which
supplies electricity to power the trains.
In the major breakdowns last December when more than 220,000
commuters were affected by service disruptions lasting five to
seven hours, 21 of these claws along a stretch of the North-South
Line were found to have been dislodged.
This caused a misalignment of the 'third rail' that, in turn,
interrupted the power supply to the trains.
Since the breakdowns, SMRT has used plastic cable ties to fasten
all the claws, which are spaced about 6m apart along each direction
of the 90km network.
SMRT would not comment on the possibility of replacing the old
claws with the new ones, which are already used in its newer lines
such as the Circle Line and Changi Airport Extension of the
East-West Line.
A company spokesman said the government-appointed inquiry that
starts next week will be looking into the issues connected with the
breakdown.
'It is best that all findings and recommendations be revealed
through the Committee of Inquiry proceedings,' the spokesman
said.
But sources said the claw replacement move is highly probable as
the cable ties are only an interim measure.
The replacement exercise is estimated to cost between $5 million
and $15 million, excluding labour.
As to who pays for this, urban transport expert Park Byung Joon
said the answer is not straightforward in this case.
He noted that under an old financial arrangement, the Government
pays for the rail infrastructure and SMRT owns, runs and maintains
the system.
In 2010, a new financial regime was put in place. In it, the
Government assumes ownership of operating assets, leasing them to
the operator for a fee that will eventually fund asset replacement.
SBS Transit's operating contract for the upcoming Downtown Line
falls under this new arrangement.
'It is an interesting question, and I don't know if there is a
right answer to that,' said Dr Park, who reckons replacement of the
claws falls in a grey area between maintenance and an
infrastructural upgrade.
'Should it be funded by taxpayers, or profits that the company
had accumulated over the years?' asked Dr Park, who is programme
head of the Master of Science programme in urban transport
management at SIM University.
'Ultimately, there has to be consensus among all the interested
parties.'
But Dr Lee Der-Horng, a transport researcher at the National
University of Singapore, said the Government should pay, 'as this
is an infrastructural work'.
However, what is of greater concern to him is whether the claws
are the only problem.
He called for investigations to go deeper to find the root
causes of the breakdowns, like vibration.
Preliminary findings by SMRT indicate that strong vibration
along the city stretch of the North-South Line may have contributed
to the claw dislodgement.
Tracks in the area are built on so-called 'floating slabs',
designed to insulate nearby high-rise buildings from the vibration
of passing trains.
CHRISTOPHER TAN
