Damaged rail on EWL replaced, endurance tests ongoing
All affected rail segments between Clementi and Ulu Pandan Depot have been replaced as work to resume service along a four-station stretch of the East-West MRT Line continues, the Land Transport Authority (LTA) said.
In a Facebook post on the morning of Sept 30, the authority added that the third rail, which supplies power to trains, has also been reinstated.
A series of tests have also been completed. These include a stress test using a locomotive, which ensures that all affected rails are sturdy and welded well, before an endurance test begins on Sept 30. This test involves running a train fully loaded with sandbags across the tracks to simulate a packed train.
An “electric meggering” test has also been completed. This test confirms that the third rail as well as the rail on which trains run are electrically insulated, to allow the engineers to switch on the traction power supply safely.
Train services between Jurong East and Buona Vista have been disrupted since Sept 25, with about 2.1 million passengers affected so far.
Rail operator SMRT and LTA are aiming to restore services on Oct 1, subject to weather conditions and after thorough testing is done for passenger safety.
SMRT had earlier aimed to restart services on Sept 30, but stress tests on Sept 28 found 12 cracks that were previously not visible on unreplaced segments of rail. This meant that engineers had to replace another 10 segments of rail along the westbound track from Clementi to Ulu Pandan Depot.
On Sept 25, a faulty train had severely damaged the tracks and trackside equipment while being withdrawn from service to the Ulu Pandan Depot.
It caused 46 rail fractures – such as cracks or chips – across 2.55km of tracks.
In a separate Facebook post on the morning of Sept 30, SMRT said that its engineers have also completed ultrasonic testing of welds, the inspection of welding by measuring the reflection of high-frequency sound waves.
The operator added that the train endurance tests are under way.
The faulty first-generation Kawasaki Heavy Industries train, which has been in service for more than 35 years, was travelling eastwards when it encountered a fault near Clementi station at about 9am on Sept 25.
It was later turned around near Queenstown station onto the westbound track, bound for Ulu Pandan Depot.
As it was being withdrawn, a defective component on the train’s undercarriage – known as an axle box – dropped onto the tracks near Dover station, and this caused the wheels of the undercarriage to run off the rail.
This wrought extensive damage to the tracks and trackside equipment as it was being taken to the depot.
The damage triggered a power trip that stalled other trains and crippled services. The train also damaged three point machines, stretches of the third rail, as well as power cables and rail fasteners.
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