Rail systems undergo tests after accidents

The operators of both the Yellow and Pink lines are currently testing redesigned guide wheel and conductor rail systems in a bid to prevent repeat malfunctions.
The roll-out follows recent incidents in which a guide wheel fell from a running Yellow Line train, damaging vehicles below, while a long section of the Pink Line’s conductor rail also fell causing similar damage.
Following these incidents, the Eastern Bangkok Monorail Co (EBM) and Northern Bangkok Monorail Co (NBM), concessionaires of the Yellow and Pink Lines respectively, have been working together with Alstom, the French producer of the monorail guide wheel and conductor rail systems.
They want to prevent any recurrences of these faults, Surapong Laoha-Unya, executive director of BTS Group Holdings Plc, told the media on Saturday. He was speaking in his capacity as a director of both EBM and NBM.
Alstom has tested the redesigned guide wheel system in-house and has now fitted it on one Yellow Line train and one Pink Line train for further testing, a process which requires about three months to finish, he said.
EBM and NBM will then begin replacing all the guide wheels on their 42 Pink Line trains and 30 Yellow Line trains early next year, he said.
Currently, the Yellow Line trains are using an unchanged guide wheel design after a safety inspection, he said, adding the frequency of inspections has been raised following the accidents.
Alstom has also redesigned the conductor rail system for both monorail lines, but it is still assessing the pros and cons of the new design, he said.
EBM and NBM have both asked that each section of the conductor rail, which is now about 5–6 kilometres long, be spilt into shorter sections to lessen the damage in case any section encounters a problem in future, he said.