Low-speed, empty stock derailment at Bletchley (26/06)

[Harpo]

Yes. Two of the switches of a diamond could divert and likely derail, due to the dog leg turn, if misaligned. Limiting the distance limits the running time from the moment the last check of the mechanism was conveyed to the driver when passing the clear signal to encountering the facing switches.

Thanks for that.

 

[MadMac]

Yes. Two of the switches of a diamond could divert and likely derail, due to the dog leg turn, if misaligned. Limiting the distance limits the running time from the moment the last check of the mechanism was conveyed to the driver when passing the clear signal to encountering the facing switches.

I’m aware of an instance where someone tried that with a ballast train: unsurprisingly, it didn’t work.

 

[LowLevel]

So does 9821 just read for a route to line R1? Would one approach 9753 from lines R1/R2 via the crossover that is immediately prior to the junction with the US?

My direct knowledge is based on the resignalling of the Bournemouth line, but I am sure that flexibility on the GN&GE was mentioned during a tour prior to the commissioning of the resignalling at Lincoln - I must have misunderstood the exact flexibility they were referring to (it is some time ago now!).

As far as I know the extra signals on the GNGE serve two purposes, one is to turn back trains via signalled moves over crossovers if necessary, and the second is to avoid the need for a handsignalman opposite the final signal during single line working as all of the Miniature Stop Light/Automatic Half Barrier crossings are also fitted with "wrong direction" controls.

They aren't except as mentioned otherwise actual signalled long bidirectional sections.

 

[Wilts Wanderer]

I’m aware of an instance where someone tried that with a ballast train: unsurprisingly, it didn’t work.

Wasn’t there a fairly recent SPAD at Stafford Trent Valley Jn where a light Class 90 successfully negotiated a set of switch diamonds without derailing and came to rest on the adjacent running line (with another train approaching the other way, luckily stopped!) That will have been a brown-trousers moment.

 

[zwk500]

Wasn’t there a fairly recent SPAD at Stafford Trent Valley Jn where a light Class 90 successfully negotiated a set of switch diamonds without derailing and came to rest on the adjacent running line (with another train approaching the other way, luckily stopped!) That will have been a brown-trousers moment.

This one? https://assets.publishing.service.gov.uk/media/66704528d2decd226612903b/R052024_240617_Stafford.pdf

 

[jfollows]

Wasn’t there a fairly recent SPAD at Stafford Trent Valley Jn where a light Class 90 successfully negotiated a set of switch diamonds without derailing and came to rest on the adjacent running line (with another train approaching the other way, luckily stopped!) That will have been a brown-trousers moment.

https://assets.publishing.service.gov.uk/media/666c20f79e5482aa40222932/R052024_240617_Stafford.pdf I think
Snap!

 

[zwk500]

1Z99 has moved towards 5Y26 and now disappeared of the open data maps sites, so is presumably attaching. Anybody know if it's planned to be directly hauled to a depot or if it will be simply moved out of the way for further asssessment?

 

[Silverlinky]

1Z99 has moved towards 5Y26 and now disappeared of the open data maps sites, so is presumably attaching. Anybody know if it's planned to be directly hauled to a depot or if it will be simply moved out of the way for further asssessment?

Being propelled onto the relief road 2. Up Fast will be blocked to allow this move to take place.

 

[midland1]

Just in case it has not been already said 1Z99 the loco is 37901 from Leicester. I was waiting for 0Z85 at Wigston South Jn. when this came along.

 

[tram21]

How long are we expecting disruption due to this to last? National Rail states until the end of the day tomorrow, but is that likely given the train is being moved/ has now moved?

 

[hexagon789]

How long are we expecting disruption due to this to last? National Rail states until the end of the day tomorrow, but is that likely given the train is being moved/ has now moved?

The track is damaged though, so that will need repairing.

 

[DaventryRabbit]

37 plus 350 still there now. Seen from 2Z48 passing .Lots of Orange Army as well.

 

[Annetts key]

How long are we expecting disruption due to this to last? National Rail states until the end of the day tomorrow, but is that likely given the train is being moved/ has now moved?

Depends on how long it takes to restore the track so that it's fit for trains to run. Its likely that some of the point work is damaged, so not all lines may be reopened initially, or part or all of the diverging routes on or off the junction may not be available.

Plus there is likely damage to the signalling equipment. If the point work cannot be repaired or replaced and plain line is fitted instead, a temporary design may be needed for part of the signalling.

 

[Falcon1200]

But, no, a switch diamond has moveable point ends to make the crossing smoother, especially at higher speeds, but the crossing can only be used as a diamond crossing.

The reason behind switched diamonds is surely that, due to the crossing angle, it is possible for wheels to take the wrong path? Possibly relevant to this incident....

I’m aware of an instance where someone tried that with a ballast train:

So am I - Haymarket East Junction?

 

[jfollows]

The reason behind switched diamonds is surely that, due to the crossing angle, it is possible for wheels to take the wrong path? Possibly relevant to this incident....

I don’t think the “reason behind” switch diamonds is that they might not work, they’re there for faster crossings because traditional diamonds might limit speed. But of course it’s possible that if they fail in some way what you describe might be possible. However they’ve been used for many years and they don’t fail in this way, otherwise we’d have heard about it. Slade Lane Junction near me has them and works fine.

 

[MarkyT]

The reason behind switched diamonds is surely that, due to the crossing angle, it is possible for wheels to take the wrong path? Possibly relevant to this incident....

The smaller the crossing angles, the longer the gap in the running surface necessary for the flange to pass through. Wheels drop further into longer gaps, creating impact damage, increasing wear to wheel and crossing, and causing a nasty jolt onboard. In extreme cases, derailment might be possible, but the ride and damage implications make very long fixed crossings undesirable on their own.

 

[David57]

And BBC Look East reporting this evening a 'freight train' derailment' is still causing problems...Sloppy, Sloppy Journalism.

 

[Tilting007]

Going from the left, thats the Down Fast, Up Fast, Down Slow, Up Slow. That layout seems to suggest the move from Up Slow (in down direction) to Down Slow is impossible.

Although the layout remained switch diamonds, this picture is before the renewal last year.

== Doublepost prevention - post automatically merged: 27 Jun 2025 ==

Yes but that was going a lot faster and the driver reported they had derailed initially.

For sure a brown trouser moment.

Also a driver that happily posted their journeys on YouTube…. Hopefully they have reviewed this after such a serious incident where they were regularly speeding.

Wasn’t there a fairly recent SPAD at Stafford Trent Valley Jn where a light Class 90 successfully negotiated a set of switch diamonds without derailing and came to rest on the adjacent running line (with another train approaching the other way, luckily stopped!) That will have been a brown-trousers moment.

 

[6Gman]

West Coast Main Line still struggling today (I've just left a rather crowded Manchester train with faulty air-con to add to the overcrowding).

Does anyone know why the Up Fast wasn't being used between Crewe and Stafford this afternoon?

It didn't help!

 

[milooo]

37901 is on the down end of the unit

 

[M60lad]

Weren't there signalling problems between Crewe and Stafford limiting how many lines could be used? Should I read something to the affect.

 

[NSEWonderer]

Looks like the slow lines will not be open tomorrow. Heard tamper staff are out of hours so have to comeback at some point, tomorrow night.

 

[zwk500]

Looks like the slow lines will not be open tomorrow. Heard tamper staff are out of hours so have to comeback at some point, tomorrow night.

1Z99 is still showing on the signalling maps, so assuming the unit hasn't been cleared yet? Is the extent of the damage to the track known in full yet?

 

[sonic2009]

The delays caused by this incident seemed to have a knock on effect up at Crewe.

The 0708 Avanti to Manchester which starts at Crewe - usally comes ECS from Longsight, but this morning was sat in Platform 12 - ran down to Crewe Sth Jn reversed and came into Platform 6 55mins late.

Avanti Platform staff said it had been there all night. Didn't look like the train had been cleaned either.

 

[800001]

The delays caused by this incident seemed to have a knock on effect up at Crewe.

The 0708 Avanti to Manchester which starts at Crewe - usally comes ECS from Longsight, but this morning was sat in Platform 12 - ran down to Crewe Sth Jn reversed and came into Platform 6 55mins late.

Avanti Platform staff said it had been there all night. Didn't look like the train had been cleaned either.

Could be due to the OHL issues which occurred yesterday in the northern section of Wcml. Not necessarily to do with the derailment:

 

[td97]

1Z99 is still showing on the signalling maps, so assuming the unit hasn't been cleared yet? Is the extent of the damage to the track known in full yet?

Correct, it was stationary on the down slow around an hour ago

 

[Silverlinky]

247 can not be moved without skates so will remain where it is overnight.

 

[NSEWonderer]

247 can not be moved without skates so will remain where it is overnight.

Not surprised that it would have needed skates, I was just confused why that hadn't been brought in after the re-railing

 

[andyjhatton]

A possibly tangential question.
Much is made of the passenger number and revenue figures.
How is delay repay factored into these?
I imagine many trevellers will have had free or much reduced fairs over the past few days.

If the railway can't actually run its timetable and everybody is travelling for free, makes you think.
(I've enjoyed a fair few cheap journeys over the years courtesy of the purely imaginary teimetable)

 

[Silverlinky]

Not surprised that it would have needed skates, I was just confused why that hadn't been brought in after the re-railing

New plan or even back to the old plan, no skates, move south tomorrow morning after 0900