Fun Fact Friday: Asymmetrical Half-Height Platform Screen Doors

Did you notice that the first and last half-height platform screen doors are different?

The half-height Platform Screen Doors (PSDs) were installed onto elevated MRT stations along the North-South Line (NSL) and East-West Line (EWL) between August 2009 and June 2012. All of the 24 doors along the platform might look the same, but the first and last doors are a wee bit different – one side of the door is smaller than the other.

Design Considerations

This design is to prevent the door nearest to the headwall and tailwall to protrude out excessively from the panel when the door is opened.

If the doors were of the same width, it would prevent staff from accessing the staff-only areas of the platform through the train cab door when the train doors are opened.

Aboveground PSDs vs Underground PSDs

This is an issue that is only present for half-height platform screen doors as the drive mechanism is located at the bottom panel next to each door.

The drive mechanism needs to be in contact with a portion of the door for it to control the door movement, and this portion of the door will protrude into the access area if the doors are of the same width.

The drive mechanism for full height platform screen doors at underground stations are located above the doors and hence, there is no need for the asymmetrical first/last platform doors.

Fun Fact Friday Series

Fun Fact Friday: Portable Fare Collection Gates

Fun Fact Friday: CC18 Station

Related Links
Platform Screen Doors – SGTrains
North-South Line – SGTrains
East-West Line – SGTrains

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Matthew Ng

An avid train enthusiast since 2009, he designs graphics and infographics to promote the little known facts about Singapore's train network.