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electroweak • yesterday at 3:23 PM • 3 replies • view on HN

How come we have collision avoidance mandated and working in 3 and 2 dimensions (TCAS, AEB), but somehow do not have it in 1-dimensional motion?


Replies

ryathal • yesterday at 8:39 PM

There's not a sensor that can detect another train with enough warning to matter. Stopping takes miles, and turning isn't an option.

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rsync • yesterday at 3:43 PM

This is exactly the thought I always have.

It seems impossible to imagine that there are any layers of defense in depth involved here… Because it should be so easy to avoid.

namibj • yesterday at 7:11 PM

Because rail is quite non line of sight and quite infrastructure defined pathing.

The automatic coordination system hit a fail condition; they neglected the fallback protocols that had rules for spacing determined to work reliably without the computer keeping real time supervision; they crashed.

This is in the way more like the Washington D.C. helicopter plane mid-air where some normalization of deviance got people to ignore automated protection systems.

If most involved had known the fallback protocols they would have refused to move/continue while the protocols were utterly neglected. At least with a robust safety culture active, ofc.