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I read your list and see a bunch of 'technical debt.' Trains put into operation without the ability to survive a power transient without intervention. Life critical backup power system failures. The set of critical sites is not being maintained properly. In my mind these failures are are not entirely unrelated; reliable power is taken for granted and the testing and maintenance necessary to cope with power outages is neglected.



This is not technical debt. These are signs of oversights or potential poor management. Indeed that's what neglecting these procedures is.

This is why a comprehensive investigation is needed to ensure the details are known and all lessons learned or, unfortunately, re-learned.


Its shockly poor procurement - those new trains are not fit for purpose.


Do you mean that they don't meet the requirements of the tender spec ("not fit for purpose") or that the spec in the tender process was deficient ("shockingly poor procurement")?


Both the older electrostars where far better


> Trains put into operation without the ability to survive a power transient without intervention.

The trains were built to a environmental tolerance spec, and shutting down when that spec is exceeded seems like a reasonable thing to do. Having an expert test that all the safety systems are still working properly after they've been exposed to conditions they weren't designed for also seems prudent.

Do you think people should pay higher ticket prices / more tax to fund trains that can tolerate a wider range of input frequencies, given how rarely these sorts of events happen?


> The trains were built to a environmental tolerance spec and shutting down when that spec is exceeded seems like a reasonable thing to do.

Yes, they were built to a spec. According to the official technical report[1] these trains DID NOT experience anything outside that spec. The shut down was not supposed to occur. The trains are simply defective and both manufacturer and operator testing failed to reveal these defects. There is no other reasonable conclusion. Defective, inadequately tested trains.

> Having an expert test that all the safety systems are still working properly after they've been exposed to conditions they weren't designed for also seems prudent.

This bit of guesswork is also contradicted in the official report as the manufacturer has committed to providing a system update to permit operation to resume WITHOUT any of your supposed 'prudence.' Resuming operation on power recovery without intervention by technicians is the specified, expected behavior. This is a separate defect that also survived whatever obviously inadequate testing regime was supposedly in effect.

> Do you think people should pay higher ticket prices / more tax to fund trains that can tolerate a wider range of input frequencies, given how rarely these sorts of events happen?

Since the official conclusion and subsequent response by the manufacturer both show the trains were specified to tolerate these conditions the extraordinary costs you imagine are a fiction; the cost has already been paid. No higher ticket prices required. And since these conditions were specified we also know they were indeed anticipated despite their infrequency.

Both the manufacturer and the operator failed here. They got caught with their pants down. You may not like hearing that for whatever reason but that's the bottom line and inventing excuses won't change it.

[1] https://news.ycombinator.com/item?id=20973513


The GP says that the frequency drop was within-specification, not exceeding spec.


Which specification though? At the time they were being designed and procured, I think the specified tolerance for frequency change rate on the grid was 0.125Hz/s, but this was relaxed in 2014 to 1Hz/s (see https://www.nationalgrideso.com/document/10771/download). How much the effects of relaxing this on existing equipment was considered, it's not clear.

Similarly, the grid's license gives them a ±1% variation around 50Hz (so ±0.5Hz from https://www.nationalgrideso.com/balancing-services/frequency...).

So we have a power anomaly where the frequency moved >0.125Hz/s and dropped well below the 49.5Hz license threshold. I don't know what the procurement spec was, but I'd be very surprised if this event was "in-spec" for the trains, so in the absence if this it's probably reasonable to say that GP is incorrect.

Transformers get quite unhappily melty if you drop the frequency too much, so if your cooling system isn't designed to cope with this, it's probably better to shut down than have an exciting fire.


The grid's license only requires them to be within ±0.5Hz of the nominal 50Hz for at least 95% of the time. Anyone designing a system which needs to operate reliably ideally ought to design it to operate over the full 47.5-52Hz range, or at least not fail so completely it cannot be restarted. Low frequency demand disconnect only starts at 48.8 Hz, ao any system that can't handle that is effectively setting itself up to be the first thing to fail when there's a power shortfall. This is utterly inexcusable for a train given the amount of disruption caused by multiple lines being clogged by failed trains in multiple places.


I don't disagree that a train that can tolerate a wider range is desirable, but lots of things are desirable. It's also desirable to give everyone their own carriage, or have a free bar on every train. But at what cost?

* Wider tolerance means heavier electrical and cooling systems, increasing both capital outlay and operating cost for both track wear and maintenance.

* The trains procured were essentially "off the shelf" from Siemens and would have been designed and manufactured for other operators before the DfT put the tender together. A wider operating tolerance would have therefore either ruled out the Siemens trains, or at least significantly upped the cost as they would have had to redesign them.

An annual season ticket from St Albans to London is about £3,600. How much more should that passenger (as well as the taxpayer) be paying so that they can travel on trains that work when this type of event happens? How often does this type of event happen?

> This is utterly inexcusable for a train given the amount of disruption caused by multiple lines being clogged by failed trains in multiple places.

People being stuck on trains for a few hours is pretty far down the severity list of "things that could go wrong" when the power goes out. That said, what I do think the outcome will be here is they'll figure out if/how the driver can self-reset this type of issue rather than requiring a fitter to travel out.




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