They should already be able to detect line breaks using old technology. They send current pulses down the line to detect stuck switches, since stuck switches can cause collisions. Also, the pulses are conducted through the wheels and axles of any trains, so they can use resistance and/or timing to figure out where the trains are.

Having said that, if it was 2020 and you told me that making photorealistic pictures of broken bridges was harder than spoofing the signals I just described, I’d say you were crazy.

The idea that a kid could do this would have seen even less plausible (that’s not to say a kid did it, just that they could have).

Anyway, since recently-intractable things are now trivial, runbooks for hoax responses need to be updated, apparently.

> They should already be able to detect line breaks using old technology.

Yes. That doesn't do much to detect a stone from a parapet rolling onto the line though.

Hence the need for inspection.

> runbooks for hoax responses need to be updated, apparently.

I'd argue not - whether it's an image of a damaged bridge, a phone call from a concerned person about an obstruction on the line, or just heavy rains or an earthquake .. the line should be inspected.

If anything urban rail is in a better position today as ideally camera networks should hopefully rapidly resolve whether a bridge is really damaged as per a fake image or not.

> They send current pulses down the line to detect stuck switches, since stuck switches can cause collisions.

That's not done in any European rail network I am aware of. The switches have, well, switches that confirm if the mechanical end positions have been reached, but there is no confirmation by current pulses on the actual rails themselves.

> Also, the pulses are conducted through the wheels and axles of any trains, so they can use resistance and/or timing to figure out where the trains are.

That technology is, at least in Germany, being phased out in favor of axle counters at the begin and end of each section, partially because axle counters allow speed and direction feedback, partially because it can be unsafe - a single locomotive braking with sand may yield a false-free signal when sand or leaves prevent the current passing from one rail to the other.

If whatever technology they installed said everything was fine, I would still want them to do what they did because the costs of being wrong are so much higher than the costs of what they did.

The point of that technology needs to be to alert you when something is wrong not to assure you that everything is fine whenever some other telemetry indicates otherwise.

Any idea how the road barriers in the USA detect a train to lower themselves? I assume it's something to do with current passed from one rail to the other through the axle?

When I stuck train wheels on my DeLorean and rode it down the tracks it lowered the barriers automatically which caused a bit of a traffic incident in Oxnard.