4 ms·

It's likely the same power fault could occur in a single train in other circumstances. When an electric train cannot access the grid reliably it would become fa

It's likely the same power fault could occur in a single train in other circumstances. When an electric train cannot access the grid reliably it would become far more dangerous - no more regenerating brakes, no reliable acceleration ... Better to force the operators to fix the boom arm / whatever other cause of power glitches with fault codes like this. Even if they false-trip when there are grid level outages.

Symbiote 5y ago
No, it was considered a design fault with these particular trains, and fixed soon afterwards. Being unable to accelerate or unable to use regenerative braking is not in any way a safety problem. Either situation can happen at any time. (Electric trains have banks of resistors used to dump the unwanted kinetic energy when it's not possible to return it to the power supply, and this was the normal method for decades before regenerative braking became common.)
- iggldiggl 5y ago
  > Electric trains have banks of resistors used to dump the unwanted kinetic energy when it's not possible to return it to the power supply On AC-electrified railways (especially those with their own independent power supply network like Germany/Austria/Switzerland), resistors are actually rather uncommon on stock capable of regenerative braking, because the OHLE not being able to accept regenerated power is a relatively rare occurrence. Though of course in that case the conventional friction brakes are of course fully rated to bring the train to halt, only with a bit more wear and tear. DC-electrified railways are a different matter – transmission losses are higher, power supply sections are smaller and substations often not capable of returning any surplus power back into higher network layers of the power supply systems, so the OHLE/third rail not being able to accept the power generated by regenerative braking happens much more frequently and so trains continue carrying braking resistors as a fallback system.

Symbiote 5y ago

No, it was considered a design fault with these particular trains, and fixed soon afterwards. Being unable to accelerate or unable to use regenerative braking is not in any way a safety problem. Either situation can happen at any time. (Electric trains have banks of resistors used to dump the unwanted kinetic energy when it's not possible to return it to the power supply, and this was the normal method for decades before regenerative braking became common.)

iggldiggl 5y ago
> Electric trains have banks of resistors used to dump the unwanted kinetic energy when it's not possible to return it to the power supply On AC-electrified railways (especially those with their own independent power supply network like Germany/Austria/Switzerland), resistors are actually rather uncommon on stock capable of regenerative braking, because the OHLE not being able to accept regenerated power is a relatively rare occurrence. Though of course in that case the conventional friction brakes are of course fully rated to bring the train to halt, only with a bit more wear and tear. DC-electrified railways are a different matter – transmission losses are higher, power supply sections are smaller and substations often not capable of returning any surplus power back into higher network layers of the power supply systems, so the OHLE/third rail not being able to accept the power generated by regenerative braking happens much more frequently and so trains continue carrying braking resistors as a fallback system.