Wednesday, March 13, 2013

Slip'n'slide on the Cleveland Line

The preliminary Australia Transport Safety Bureau (ATSB) report into the Cleveland train crash has now been released. The cause of the crash was not a total brake failure as the "hysterical" unionists claimed, but due to poor rail adhesion from leaf fall and light rain. Multiple trains had experienced adhesion issues around Ormiston station that morning. When the driver of train T842 came to brake at Cleveland, the train failed to sufficiently slow down, sliding through Cleveland station and into the mens toilets at 31kph, injuring many passengers.

Poor rail adhesion is a known issue in many temperate climates (such as the UK), particularly during the leaf fall season, which is not an issue in Queensland where deciduous trees are rare. However, Queensland does have a storm season where leaves and other vegetation can fall onto the tracks as occurred just before the Cleveland crash. Blossom falls could also potentially cause issues from Autumn through to Spring. Even migrating caterpillars have been reported to cause rail adhesion issues in Australia.

Also, most new trains (including Queensland Rail's class 160 and 260 trains) have brakes on disks on the side of the wheel, instead of tread brakes on the actual wheel tread. This means that the wheel tread is not cleaned (or partially cleaned) of slippery substances during each braking cycle.

So what can be learnt from UK rail operators who appear to survive the leaf fall season with no crashes?

  • Water jets - These clean the rails of material that may cause poor rail adhesion. Usually on special vehicles, which also have sandite equipment. 
  • Sandite trains - These deposit a sand paste onto the rails, either fitted to normal trains or special vehicles. 
  • Driving adjustment - UK train operating companies usually modify timetables during the leaf fall season to allow for more cautious driving. Given by how much QR pad out their timetables, this could probably be done at any time there is a rail adhesion risk on tracks without causing considerable delays. 
  • Reduce line-side vegetation - This is already being done by QR after various storm season line shutdowns and a stray bouganvilla that caused rail chaos. 
The ATSB report concluded "Queensland Rail’s risk management procedures did not sufficiently mitigate risk to the safe operation of trains in circumstances when local environmental conditions result in contaminated rail running surfaces and reduced wheel/rail adhesion". BrizCommuter hopes that Queensland Rail (and other Australian rail operators) take serious action on the risk of poor rail adhesion. QR have already formed a "Wheel Rail Interface Working Group". 

BrizCommuter is dissappointed that the ATSB report does not address the dangerous terminus design with buildings immediately beyond the end of the track, and lack of modern train arrestors. However, it should be noted that QR's potentially dangerous lack of Automatic Train Protection (ATP) would not have prevented this crash. 

ATSB preliminary report:

3 comments:

  1. Do I get credit for pointing this out and posting about it? :)

    ReplyDelete
  2. Garvin - yes, you win a bag of sandite.

    ReplyDelete
  3. Ridiculous that no mention of the public facilities at the end of the tracks was made.

    ReplyDelete

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