Lumo overspeed incident at Peterborough (17/04/2022)

[ASharpe]

The screenshot you’ve posted only shows one train so I’m not quite sure what you’re asking. Each of these signals is capable of showing a red aspect therefore the space from one signal to another is a block and they function like any other signal in 4-aspect signalling. They are not there solely for the approach control, indeed they can all show green for the appropriate route.

If they can show red then I don't understand why at the very bottom P474 isn't showing red.

And if it's 4 aspect signalling why isn't P486 a double yellow.

 

[Sheridan]

If they can show red then I don't understand why at the very bottom P474 isn't showing red.

And if it's 4 aspect signalling why isn't P486 a double yellow.

I believe that P474 should be showing red in that example and it’s simply an error in the production of the diagram. It’s showing red on the line above.

 

[ASharpe]

I believe that P474 should be showing red in that example and it’s simply an error in the production of the diagram. It’s showing red on the line above.

That makes a lot more sense to me. I shouldn't over think it after the pub.

Edit: I suppose nobody expects a wrong side failure.

 

[plugwash]

why didn't it tip over? How much was left in the bank so to speak ?

The RAIB report seems to think "not much".

 

[Railsigns]

There used to be a maximum approach speed for Theatre Indicators of 40 MPH - it also used to be that they had to display an indication for all routes including the “straight“ one, although I believe that’s no longer the case.

To be honest, I think that BR's Standard Signalling Principles always contained provision for a theatre indicator to display an indication for every route apart from the highest speed one. The original versions from 1960 certainly did.

There are real-life examples at Barrhead and Dalmuir, both originating from the 1970s.

 

[MotCO]

post deleted

 

[Watershed]

Another layman with probably another stupid question - sorry!

As I understand it, the vast majority of trains stop at Peterborough, and only the Lumo services pass through (plus possibly a non-stop Scotland to London service?). If that is the case, would it make sense to impose a speed limit (50mph?) on the approach to the station? Most trains would be slowing down anyway to stop, and if a train was on the diverging route, the lower speed limit would prepare the driver for the slower speed.

The acceleration of the 800 class would seem to be such that there would be little time penalty for the through services.

In the ideal world this would not be necessary, but belt and braces.....?

There are actually quite a lot of non-stop trains - in each direction there's 1tph LNER London to Scotland, 10tpd Grand Central, 7tpd Hull Trains and 5tpd Lumo, as well as a variety of largely diesel-hauled freight trains. So the effect on the timetable would be quite significant overall.

Don't get me wrong - a TSR or ESR with a 50mph speed limit could certainly have been imposed if it were deemed necessary on safety grounds. But evidently the modifications that NR have made have been deemed sufficient. I'm not entirely convinced of that, but the ORR seems to be happy with it (although they seem to be very much a light touch regulator in a lot of areas).

 

[Signal Head]

Paragraph 198 says that Network Rail have changed the signal to display yellow rather than green when a diverging route is set, so it is clearly not a silly idea.

It states this has been done using 'temporary approach control'. TAC on the junction signal would hold it at red until the train reached the release point, so I am wondering if what has been done is to apply TAC to the following signals, so then the normal aspect controls will enforce max Y on P468, ie it does not need a data change (I think PB area has been SSI for some years).

Because this is a simple 'all or nothing' control, it will apply irrespective of which signal in rear the approach is from, so it would also restrict the speed of those movements uneccessarily.

There was a practice many years ago of using a '2 stage' release, where the junction signal would step up R>Y initially, with the train some distance away, but Y>G step up was delayed until the train had passed over the AWS magnet, so an AWS Caution was always enforced for the lower speed route.

That method of approach release hasn't been permitted for new work for some years, but I did something similar more recently where we wanted to relax some very tight existing controls which were forcing heavy freights down to walking pace, for a 20MPH divergence, simply because of the principles applied when the signalling was installed some decades previously.

Perhaps a reintroduction for instances like this, where the combination of a potentially catastrophic speed differential coupled with long distances between release/signal/points makes observation and correct processing of the JI meaning absolutely critical, might be considered.

== Doublepost prevention - post automatically merged: 12 Jul 2023 ==

Maybe non-standard but perhaps G/Y in top position and R/Y (for double Y) in bottom position.

The LED modules are manufactured as R/Y/G, and Y only (for the top yellow of a four aspect signal). The combinations you propose just aren't made.

== Doublepost prevention - post automatically merged: 12 Jul 2023 ==

To be honest, I think that BR's Standard Signalling Principles always contained provision for a theatre indicator to display an indication for every route apart from the highest speed one. The original versions from 1960 certainly did.

There are real-life examples at Barrhead and Dalmuir, both originating from the 1970s.

I never recall seeing this being with the old 7x7 theatres, but then they tended to be in such positions where speed for all routes was low anyway, on the approach to terminal stations and so on.

That's not to say principles didn't allow for it, and it has certainly been done in more recent years (and I've just realised that 'more recent', in my head, includes a resignalling from a little over 30 years ago!), with fibre-optic RIs. One stipulation being that the RI must be proved alight when required, as with a JI. That would certainly have been feasible with the original pattern too.

== Doublepost prevention - post automatically merged: 12 Jul 2023 ==

So in that case why put the key route indicator further up still ?

It is noticeable how many of the recent serious signal misreads (Southall, Ladbroke Grove, now Peterborough twice) were all with signals up among the overhead wires. It would have been good to have a shot in the report from further back, the point when the signal changed.

I do wonder why the RAIB selected the shot of the signal, a nice bright green with a pretty poor set of indicator lights above (they are, look at the picture), for the front cover of the report. They do have form in, with the way that they edit their documents, Sending a Message ...

The JI is where it is because the support frame is sized to fit over a conventional 4-aspect head (filament type), which is what was provided originally.

The Dorman LED head accommodates three aspects in the lower aperture and the 2nd (top) yellow in the upper aperture. You still need space between the two yellows to stop them merging at a distance, so a 4-aspect LED signal head is roughly the same height as a 3-aspect filament one. The top aspect will be roughly where the 'filament' green aspect would have been.

 

[edwin_m]

The LED modules are manufactured as R/Y/G, and Y only (for the top yellow of a four aspect signal). The combinations you propose just aren't made.

I guess there's no reason why a non-standard signal couldn't be put together with two of the R/Y/G ones, so the red could be displayed in the upper one nearer to the JI. But putting it further from the driver's eyeline would create moe hazards.

The JI is where it is because the support frame is sized to fit over a conventional 4-aspect head (filament type), which is what was provided originally.

Again, imagine it would be possible to replace the frame with a shorter one to bring the JI closer to the green, removing the gap that was originally needed for the separate upper yellow lens.

 

[Signal Head]

I guess there's no reason why a non-standard signal couldn't be put together with two of the R/Y/G ones, so the red could be displayed in the upper one nearer to the JI. But putting it further from the driver's eyeline would create moe hazards.

Again, imagine it would be possible to replace the frame with a shorter one to bring the JI closer to the green, removing the gap that was originally needed for the separate upper yellow lens.

1) from memory, the R/Y/G modules will not physically fit in the upper position.

2) yes, the frame could be replaced with a 3-aspect one, but clearly this wasn't done when the head was replaced - possibly because this was done under maintenance as 'like for like' without going through the sighting process beforehand, so altering the height of the JIs may have been avoided deliberately.

 

[CC 72100]

There was a practice many years ago of using a '2 stage' release, where the junction signal would step up R>Y initially, with the train some distance away, but Y>G step up was delayed until the train had passed over the AWS magnet, so an AWS Caution was always enforced for the lower speed route.

That method of approach release hasn't been permitted for new work for some years, but I did something similar more recently where we wanted to relax some very tight existing controls which were forcing heavy freights down to walking pace, for a 20MPH divergence, simply because of the principles applied when the signalling was installed some decades previously.

Signing a route where this method is used on some of the junctions, the only risk this can generate is habituation of the signal stepping up to Green.

If it is going to step up from Y to G then this takes place after passing over the AWS magnet, and does 85-90% of the time.

The risk is that the next signal is only a short distance away on the diverging route, and with it stepping up most of the time, there is a risk of a TPWS at the next signal if a driver has taken power as if it were Green through habituation, not nothing that today it didn't step up and they joined the diverging route on a Single Yellow.

 

[Stampy]

Then it all depends what other trains, GTR, Great Northern etc are on the slow lines, Peterborough May have been the easiest place to get the trains back into correct order

I got to Peterborough station just AFTER the incident occurred, as I was catching 1145 Thameslink train down to Hitchin as I'd just missed the 1115.

IIRC, the Lumo was 3/4 of the way out of Platform 1, whilst MY Thameslink train was in Platform 2, and a LNER train was in Platform 3.

The Lumo crawled out of the station onto the Up Slow line, whilst WE left at the same time on the Up Fast.

BOTH the Lumo and the LNER passed my train between Huntingdon and St. Neots

 

[12LDA28C]

This is absolutely not correct.

Really? So a driver can drive over a route they have never driven or refreshed within their employer's mandated timescale? Is it not a driver's responsibility to maintain their own route and traction competence? If a driver had a SPaD and the subsequent investigation found that they had never actually driven a train over that loop or whatever, the proverbial would most likely hit the fan.

 

[800001]

I got to Peterborough station just AFTER the incident occurred, as I was catching 1145 Thameslink train down to Hitchin as I'd just missed the 1115.

IIRC, the Lumo was 3/4 of the way out of Platform 1, whilst MY Thameslink train was in Platform 2, and a LNER train was in Platform 3.

The Lumo crawled out of the station onto the Up Slow line, whilst WE left at the same time on the Up Fast.

BOTH the Lumo and the LNER passed my train between Huntingdon and St. Neots

This is completely irrelevant.
The Lumo had been stopped at Peterborough due to the incident for about 30 minutes.

 

[Dai Corner]

Really? So a driver can drive over a route they have never driven or refreshed within their employer's mandated timescale? Is it not a driver's responsibility to maintain their own route and traction competence?

Note the difference in terminology. A 'route' must be learned and refreshed at prescribed intervals. Drivers are deemed to know every 'line' (as in fast/slow for example) if they know the route. They may indeed not have driven over a particular line for years, or at all.

 

[12LDA28C]

Note the difference in terminology. A 'route' must be learned and refreshed at prescribed intervals. Drivers are deemed to know every 'line' (as in fast/slow for example) if they know the route. They may indeed not have driven over a particular line for years, or at all.

Yes indeed. In which case the driver should make their manager aware that they haven't been into X siding or through Y loop for a long time and would like a refresher. Of course the back up is that they confirm things with the signaller before making the move, as they would for any unfamiliar move but it's less than ideal.

 

[Tomnick]

Yes indeed. In which case the driver should make their manager aware that they haven't been into X siding or through Y loop for a long time and would like a refresher. Of course the back up is that they confirm things with the signaller before making the move, as they would for any unfamiliar move but it's less than ideal.

It'd take me all day to list every single running line and siding that I've not been over in the ~650 route miles that I sign and probably weeks of route refreshing to actually cover them all! There's absolutely no need for it. I sign the route, I go over the route regularly enough, I'm expected to know all the possible moves. I've no problem with discussing a particularly complex shunt move with the signaller and/or referring to my maps, but I wouldn't be expected to do that just because it's not a move that I've done for a while or ever before. Indeed, I don't know what help the signaller would be able to give me anyway, especially with regard to things like speeds through crossovers.

 

[12LDA28C]

It'd take me all day to list every single running line and siding that I've not been over in the ~650 route miles that I sign and probably weeks of route refreshing to actually cover them all! There's absolutely no need for it. I sign the route, I go over the route regularly enough, I'm expected to know all the possible moves. I've no problem with discussing a particularly complex shunt move with the signaller and/or referring to my maps, but I wouldn't be expected to do that just because it's not a move that I've done for a while or ever before. Indeed, I don't know what help the signaller would be able to give me anyway, especially with regard to things like speeds through crossovers.

That's fine but in today's culture of delay attribution, blame and arse-covering, if you had an incident and it turned out that you'd never driven over that line then the chances are your employer would hang you out to dry.

 

[Dieseldriver]

That's fine but in today's culture of delay attribution, blame and arse-covering, if you had an incident and it turned out that you'd never driven over that line then the chances are your employer would hang you out to dry.

No they wouldn’t.

 

[MotCO]

It'd take me all day to list every single running line and siding that I've not been over in the ~650 route miles that I sign and probably weeks of route refreshing to actually cover them all! There's absolutely no need for it. I sign the route, I go over the route regularly enough, I'm expected to know all the possible moves. I've no problem with discussing a particularly complex shunt move with the signaller and/or referring to my maps, but I wouldn't be expected to do that just because it's not a move that I've done for a while or ever before. Indeed, I don't know what help the signaller would be able to give me anyway, especially with regard to things like speeds through crossovers.

Would you travel at line speed over non-signed routes, or would you restrict yourself to say 40mph so that you can react to the unexpected?

 

[66701GBRF]

I think some might be mixing up non-signed routes and routes that are signed but certain moves either not experienced or experienced a long time ago. No driver will travel over a route they don't actually sign.

 

[Dieseldriver]

Would you travel at line speed over non-signed routes, or would you restrict yourself to say 40mph so that you can react to the unexpected?

The routes he’s referring to would be low speed loops/sidings. There’s no way a Driver would be able to traverse every single crossover or running line whilst learning a route, it’s not practical. Whilst route learning a lot of time will be spent looking at maps aswell as physically travelling over the route and most Drivers (including myself) will have a look at route maps occasionally to refresh themselves with more obscure moves.

 

[skyhigh]

Would you travel at line speed over non-signed routes, or would you restrict yourself to say 40mph so that you can react to the unexpected?

Note they are not discussing non-signed routes, they are discussing lines they have not travelled over for a period of time. There's a significant difference.

 

[357]

Really? So a driver can drive over a route they have never driven or refreshed within their employer's mandated timescale? Is it not a driver's responsibility to maintain their own route and traction competence? If a driver had a SPaD and the subsequent investigation found that they had never actually driven a train over that loop or whatever, the proverbial would most likely hit the fan.

It absolutely wouldn't, and doesn't. Maps, videos, and front ending is available for drivers to familiarize themselves.

I used to sign various bits I'd never driven including the line from Limehouse to Stratford (Bow Single Line).

 

[12LDA28C]

It absolutely wouldn't, and doesn't. Maps, videos, and front ending is available for drivers to familiarize themselves.

So refreshing then, in essence. Many drivers are not big fans of refreshing by video but that's getting rather off-topic.

 

[357]

So refreshing then, in essence. Many drivers are not big fans of refreshing by video but that's getting rather off-topic.

I've learnt stuff from scratch from video or maps without ever driving it until I was on my own. I wouldn't call that refreshing.

 

[12LDA28C]

I've learnt stuff from scratch from video or maps without ever driving it until I was on my own. I wouldn't call that refreshing.

And I wouldn't call that a good way to route learn.

 

[357]

And I wouldn't call that a good way to route learn.

Neither would I, but that's the way the TOC I used to work for decided to do things.

My request of a route learning train whilst I was a trainee to cover these lines and moves was rejected multiple times.

 

[Tomnick]

That's fine but in today's culture of delay attribution, blame and arse-covering, if you had an incident and it turned out that you'd never driven over that line then the chances are your employer would hang you out to dry.

No, they wouldn't.

Would you travel at line speed over non-signed routes, or would you restrict yourself to say 40mph so that you can react to the unexpected?

We wouldn't travel over non-signed routes. We're talking about individual running lines on routes that we do sign, but where we've not made the specific move in question for a long time (if ever).

The routes he’s referring to would be low speed loops/sidings. There’s no way a Driver would be able to traverse every single crossover or running line whilst learning a route, it’s not practical. Whilst route learning a lot of time will be spent looking at maps aswell as physically travelling over the route and most Drivers (including myself) will have a look at route maps occasionally to refresh themselves with more obscure moves.

Spot on. That, and the fact that in 99.9% of cases, these lines and crossovers are immediately adjacent to or between the lines that we do use routinely, so just driving through normally is a pretty good refresher for most of what we need to know. It's no different to things like level crossing names - you don't need to refer to them routinely in most cases, but you still have to know them!

 

[MichaelAMW]

To be honest, I think that BR's Standard Signalling Principles always contained provision for a theatre indicator to display an indication for every route apart from the highest speed one. The original versions from 1960 certainly did.

There are real-life examples at Barrhead and Dalmuir, both originating from the 1970s.

Yes, that's correct, in the sense that I have observed it. The first time I noticed this was on the down relief entering Reading: theatre box for various platforms, and possibly even the up fast in the down direction, but blank for platform 8, the 'main' route.

Also, a pal who works for GBRF has shown me a Dec 2013 signalling notice, Peterborough station capacity enhancements or something like that, and the adjacent signal on the up slow approaching Peterborough appears to have that very arrangement - theatre blank for straight route to platform 1.