Major Power Failure Between Kings Cross and Stevenage 27/07/25

[Hadders]

After over running engineering works there's now been a power supply failure between Kings Cross and Stevenage. Nothing running between Kings Cross and Stevenage on the mainline or via the Hertford Loop.

GTR are reporting:

https://www.thameslinkrailway.com/service-updates/service-updates?uq=638892111633060000#INC9A26020108BF4EFEA0CC5A54C501FAD2

The earlier overrunning engineering works between Finsbury Park and Stevenage have now been completed.

However, there is a failure of the electricity supply between London and Stevenage, causing further disruption to journeys.

As a result of these incidents, trains running between these stations may be cancelled, delayed by up to 120 minutes or revised.

Major disruption is expected until the end of the day.

LNER, Lumo, GC and Hull Trains also impacted.

Does anyone know anything more?

 

[Bald Rick]

Power back on, but inevitably disruption will continue for a while.

 

[Failed Unit]

Looks like it failed a couple of times, as services did leave WGC between 1000 and 1100 (but didn’t make it). Now nothing on GTR until 1400 (but as Bald Rick states things are running again out of KX)

Now heading to St Albans, hopefully they will let me use the return portion of my ticket to get me to WGC. No websites would sell me one from WGC this morning.

 

[stuartmoss]

Letchworth is still showing all trains as cancelled, I was going to pop down to Hatfield.

 

[Failed Unit]

Letchworth is still showing all trains as cancelled, I was going to pop down to Hatfield.

Don’t bother. Head to the Midland Mainline.

 

[Crossover]

I don’t know too much of the going’s on, but I do know the 1200 from York has departed South, as a friend is on it (who was incidentally shafted by the Leeds issues yesterday too)

How it’ll get on remains to be seen

 

[Hadders]

Power back on, but inevitably disruption will continue for a while.

Excellent news! I’m out in London later today so hopefully won’t need to drive over to St Albans or Elstree.

Just walked by Stevenage station and seen a non-stop Azuma heading south with pantograph up.

 

[Crossover]

I don’t know too much of the going’s on, but I do know the 1200 from York has departed South, as a friend is on it (who was incidentally shafted by the Leeds issues yesterday too)

How it’ll get on remains to be seen

It looks to be progressing well with no more time lost and is now around Hatfield

 

[ejstubbs]

13:30 Kings Cross to Edinburgh was cancelled. 12:30 ran 80 minutes late, so ended up with two train loads of passengers on one train, running full and standing. Train manager announcing "there are more trains scheduled, you may prefer to wait for a later train" but no information provided as to when that might be so understandably very few if any were prepared to take the chance.

 

[mike57]

Just come through Doncaster and its still chaotic. Several LNER services cancelled and other running between 15 and 80 minutes late. Hull trains cancelled due to industrial action. Some Northern services cancelled as well. Fortunately my train home is running.

 

[Mainliner]

Waiting at Morpeth for the 1E86 Lumo to London. Currently 104 minutes late, it left Edinburgh a couple of minutes after the 1E25 LNER stopper, but I was pleased to watch 1E86 pass 1E25 at Dunbar on Signalmaps Every little helps, as does a refund!

 

[LarryRailer]

I’m on the LNER KGX-ABD 1400 that was delayed for 71 minutes before finally leaving London. These are bi-mode trains, right? Given the nature of the fault (no electrical power, not OLE damaged?) could they not have run on diesel as far as Stevenage? Asking for a fellow passenger - I could not think of a good answer!

 

[800001]

I’m on the LNER KGX-ABD 1400 that was delayed for 71 minutes before finally leaving London. These are bi-mode trains, right? Given the nature of the fault (no electrical power, not OLE damaged?) could they not have run on diesel as far as Stevenage? Asking for a fellow passenger - I could not think of a good answer!

Where were the crew for the service? Were they in London?

Where was the stock? Had that arrived in London?

Were other electric trains stuck and blocking the route?

Just a few questions that may be a reason why it left late

Edit - a 2 second search on RTT shows the stock for that service arriving off 1A25 which was 60 minutes late at 13:56.

 

[D6130]

I’m on the LNER KGX-ABD 1400 that was delayed for 71 minutes before finally leaving London. These are bi-mode trains, right? Given the nature of the fault (no electrical power, not OLE damaged?) could they not have run on diesel as far as Stevenage? Asking for a fellow passenger - I could not think of a good answer!

It would depend on whether or not the power outage was also affecting the signalling system.

 

[High Dyke]

Made me an hour late into King's Cross this morning (1A16), having a couple of stop/starts after Potters Bar. Luckily, I had sufficient time get to the Oval for the cricket.

Returning North this evening has been without any issues, so far.

 

[LarryRailer]

Thanks @800001. Ah, that makes sense then. Sadly, the lady who asked me the question left the train at Leuchars, so will remain none the wiser. But at least I now understand!

 

[mm333]

I went through Kings Cross just after 1700 and they were only showing the confirmed services on the board.

The only services displayed were the 1710 to Kings Lynn, 1722 to Doncaster, 1730 to Edinburgh and (I think) the 1827 to Newcastle.

I was booked on the 1735 to Leeds and that wasn’t on the board so I got on the 1722. The platform for the 1735 was called whilst I was sat on board the 1722 waiting for it to depart but stayed on and changed at Doncaster.

 

[Banham7]

Made me an hour late into King's Cross this morning (1A16), having a couple of stop/starts after Potters Bar. Luckily, I had sufficient time get to the Oval for the cricket.

Returning North this evening has been without any issues, so far.

I was on the same train, was hopeful that the stop at New Barnet would be it, but the stop at New Southgate felt like it took forever! Seems it was more the wire issue at Harringay that affected us than the overrunning engineering works.

 

[High Dyke]

I asked some learned colleagues about the subject. Seemingly National Grud had identified faults in two feeder stations and tried to divert it through a third feeder, but the system isn't designed to cope. Apparently.

 

[Spartacus]

I asked some learned colleagues about the subject. Seemingly National Grud had identified faults in two feeder stations and tried to divert it through a third feeder, but the system isn't designed to cope. Apparently.

Pretty much. Could have coped with 2 into 1, but not 3.

 

[TheGrew]

It was carnage at King's Cross when I tried to return to Hitchin yesterday at around 12:30 pm. I quickly confirmed ticket acceptance for 'Thameslink' services and went across to St Pancras to catch the next Bedford train as far as Luton Airport Parkway, before taking an Uber for the rest of the way.

 

[ABB125]

I asked some learned colleagues about the subject. Seemingly National Grud had identified faults in two feeder stations and tried to divert it through a third feeder, but the system isn't designed to cope. Apparently.

Pretty much. Could have coped with 2 into 1, but not 3.

To clarify, is that faults at two grid to Network Rail substations, so they (NG) tried to send all the power through the next nearest substation? Which obviously was not able to cope with three substations of load so shut down?
Presumably Network Rail would have been involved in this decision making, unless it was very sudden?

 

[mike57]

Pretty much. Could have coped with 2 into 1, but not 3.

But surely that is basic stuff 'power requirement = xxxMVA, feeder station capacity = less than xxxMVA' so the result is trip or bang. And if power is limited common sense would say contact all drivers of bi-modes and ask them to switch to diesel power. Hopefully leaving enough for the electric only stuff.

 

[Crossover]

But surely that is basic stuff 'power requirement = xxxMVA, feeder station capacity = less than xxxMVA' so the result is trip or bang. And if power is limited common sense would say contact all drivers of bi-modes and ask them to switch to diesel power. Hopefully leaving enough for the electric only stuff.

My understanding is that it isn’t that straightforward to switch to diesel and that it all has to be agreed with Hitachi first

 

[mike57]

My understanding is that it isn’t that straightforward to switch to diesel and that it all has to be agreed with Hitachi first

Certainly on the 802 journeys to or from Hull the changeover happens just north of Doncaster on the move. Not sure about current TPE situation, previously Liverpool Newcastle services would swap in Man Vic and York, but with wiring now reaching Stalybridge changeover point may have moved, but it seems seemless.

Maybe we need to look at our procurement strategy if Hitachi need to be involved, because that is definitely a case of the tail wagging the dog. I can understand Hitachi basing their maintenance charges on engine hours, but not controlling when and where it can be used, as that surely is a major plus point of bi-modes, to keep a basic service running when things go wrong.

 

[800001]

My understanding is that it isn’t that straightforward to switch to diesel and that it all has to be agreed with Hitachi first

Bimode is a simple press a button to pre heat engine then switch to diesel or in emergency to straight diesel at press of a button.

To switch an 801 electric set to isn't one diesel engine requires the train to be stopped and then it's slightly more technical to switch to the engine.

And no, it does not have to be agreed by Hitachi. Certainly not at LNER.

 

[ejstubbs]

The train I was on, the 12:30 Kings Cross to Edinburgh running 85 minutes late when I boarded at Peterborough. I had to stand until we reached York, by which time the train had been announced as terminating at Newcastle, with no explanation as to why (though I could guess at few possible reasons).

I managed to book a seat from Newcastle to Edinburgh on the 113 minutes late 13:00 from Kings Cross to Edinburgh. While I was waiting for that train, the cancelled 12:30 departed empty northbound from platform 3, watched by a large and disgruntled gaggle of passengers who had just been booted off it.

Fortunately I was able to occupy my reserved seat and arrive at Edinburgh (another 10 minutes down, lost between Belford and Tweedmouth) feeling somewhat less haggard.

Claiming my Delay Repay was confusing. The web page kept insisting that I must have been intending to change at York from the outset; it couldn't seem to understand that I had originally intended to travel direct from Peterborough to Edinburgh, despite the fact that I had a seat booked all the way on that train. I'm guessing that the cancellation beyond Newcastle confused it. I eventually got it to accept my claim by entering the three separate trains I actually took (including the non-delayed first leg of the journey from Cambridge to Peterborough), but I had to work that out for myself since the error messages it was giving me were unhelpful to say the least. Fortunately I knew exactly which trains I had taken and what their originally scheduled times were. Passengers who aren't aware of, or adept at navigating, services like RealTimeTrains couold well have found it much more difficult.

(My confusion in this case was probably confounded by the fact that this was the first time that I had had to claim Delay Repay for a Super Off-Peak ticket. Though TBH I'm not sure whether the system would have been able to make sense of the situation even if I'd been on an Advance, due to the cancellation at Newcastle.)

 

[Spartacus]

To clarify, is that faults at two grid to Network Rail substations, so they (NG) tried to send all the power through the next nearest substation? Which obviously was not able to cope with three substations of load so shut down?
Presumably Network Rail would have been involved in this decision making, unless it was very sudden?

Not just thought the nearest substation, but offloading it onto NR because that substation couldn't cope.

== Doublepost prevention - post automatically merged: 28 Jul 2025 ==

But surely that is basic stuff 'power requirement = xxxMVA, feeder station capacity = less than xxxMVA' so the result is trip or bang. And if power is limited common sense would say contact all drivers of bi-modes and ask them to switch to diesel power. Hopefully leaving enough for the electric only stuff.

Everything was going along fine for about two hours, when, I'm only guessing now that the National Grid needed to offload more onto NR, the feed became unstable or something tripped their side, because 700s started tripping with VCB faults. Switching to diesel is only of any use if you aren't trapped trapped by a failed electric in front, and possibly behind you, but I think everything that could was meant to be on diesel anyway.

== Doublepost prevention - post automatically merged: 28 Jul 2025 ==

My understanding is that it isn’t that straightforward to switch to diesel and that it all has to be agreed with Hitachi first

It can be done very quickly when required, though the preference is for a slower process. Certain operators prefer this even when an emergency switchover is required, though my understanding is all bi-modes were meant to be on diesel already.

 

[Crossover]

And no, it does not have to be agreed by Hitachi. Certainly not at LNER.

Was it a requirement at some point? I vaguely recall some massive ‘hoo-ha’ over it (may have been cold starting though) around the Neville Hill Azuma vs HST incident

 

[ejstubbs]

I was on the same train, was hopeful that the stop at New Barnet would be it, but the stop at New Southgate felt like it took forever! Seems it was more the wire issue at Harringay that affected us than the overrunning engineering works.

Was there a wires down incident as well as the power failure? The announcements at Peterborough did seem to be blaming two separate causes for the delays in and out of Kings Cross (plus a road vehicle hitting a bridge was mentioned, although that wasn't on the ECML; IIRC it was an EMR Sheffield to Norwich train that was affected).