Crack in MRT rail 'no risk to safety'
SINGAPORE - SMRT is still investigating the cause of a rail crack that delayed services on the North-South Line on Monday evening, but said the damage was rare and posed no risk to safety.
The Land Transport Authority (LTA) said it too has launched an investigation into the incident. It added: "SMRT needs to further improve on incident management, especially in providing more accurate and timely information... so that commuters can make alternative travel arrangements."
In a statement issued 20 hours after the incident, SMRT said the reason for the rail crack is still being investigated, although at its financial results briefing on Tuesday, the company said the crack was likely to have been caused by "heavy wear and tear".
SMRT executive vice-president for trains Khoo Hean Siang said cracks do not happen often. "We see them maybe once a year, or none at all," he said. "However, the trains are safe because they will slow down to 4-5kmh."
This drop in speed delayed travel times and caused overcrowding at several stations on Monday.
In its statement, SMRT said the crack was located in a welded area between two rails. Its engineers temporarily installed G-clamps to secure the section, it added, but trains had to travel slowly so as not to put pressure on the clamps.
Engineers have since replaced the damaged rail and services returned to normal speeds of up to 80kmh on Tuesday morning.
Northbound trains were running at one to three-minute intervals during the morning peak, while commuter traffic at stations like Dhoby Ghaut, City Hall, Raffles Place and Marina Bay was normal - a stark contrast to Monday evening, when queues spilled onto platform stairs.
SMRT said it will step up measures to ensure that rail cracks do not disrupt services.
It said that it conducts ultra- sonic tests to detect cracks every four months, and the affected stretch was inspected just last Thursday. In addition, visual inspections are carried out weekly.
Rail cracks are often caused by fatigue and can lead to derailments. They may not be completely avoidable, especially in older systems.
The Washington Metro had 49 reports of cracked rails in 2011, up from 33 in 2010 and 19 in 2009. Experts quoted by The Washington Post said the causes include the use of longer and heavier trains, the age of the system, water leaks and poor maintenance. Bosses of Hong Kong's MTR say fewer than 10 cracks are found a year.
SMRT refused to give information on the number of cracks found on its tracks in the past.
It also declined to provide photos of the incident site, saying it was a matter of "transport and national security".
Additional reporting by Jermyn Chow
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