Bristol Temple Meads - station, facilities, incidents and events (merged posts)

[whole diary]

[ellendune]

I'm informed that the present signal box building currently blocking the access to the proposed new platforms in the old Digby Wyatt shed at TM^‡(resolve) is to be relocated (at Didcot I believe) as part of the GWR^▸ (Great Western Railway) electrification.  Thing is, even with the publicised delays in electrification getting to TM, surely time is running out to get this started. Does anyone know if or when we'll see some sign of movement there? I'm not a civil engineer but I can see there's a bit of work to do there.

I take it you are referring to the resignalling (or is it re-control or is it relocking and recontrol? - I get so confused) of the signals that are currently controlled by the Bristol panel. This would transfer control of these signals to Didcot. 

There is still plenty of time to do this before electrification, but the closure of Swindon panel has been heavily delayed and there is a shortage of signalling resources.  I am sure it can still be done before the current planned date for electrification as the current signalling would be adversely affected by electric trains - it is therefore an essential part of the work. 

I am a civil engineer and I cannot help you any further - you need a S&T^▸ (Signalling and Telegraph) engineer to fully answer your question.  Now where would we find one of those? 

Calling "SandTEngineer"

[TonyK]

Much preparatory work is under way for the new signalling. As with all big projects, the graft is in the preparation, with the installation and commissioning of the actual kit the last acts. Once the new signalling is up and running, the Bristol signal box will put up little resistance to even a small bulldozer. Look beyond the end of platform 1 towards what is now a car park, and you will see the line of the new platform for the IEP^▸ (Intercity Express Program / Project.). Look down, and you will see that the signal box was built on the track bed and platform. Reinstatement should be straightforward.

[SandTEngineer]

I'm here.......

The Bristol area resignalling extends to replacing the existing interlockings and trackside equipment (excluding signals which will be reused where possible).  This is due to the existing equipment not being AC Immune and hence not immune to 25Kv AC electrification.  The exception to this will be the equipment in the Cogload Junction to Flax Bourton (125 mile post from London) area which will not be changed as it is outside of the electrified area.  The track layouts will not be changed.  This is therefore a part resignalling and part re-control project.

The bases for new trackside equipment cases and rooms are being installed now but the detailed design and build of them is somewhat behind schedule.

The 'new' signalling will be controlled from Thames Valley Signalling Centre (TVSC^» (Thames Valley Signalling Centre - about)) at Didcot (which is going to be renamed at some point in the future).  All existing Bristol signals that are numbered Bxxx will be renumbered BLxxxx.  Track circuits will be replaced by axle counters.  The existing 'X' signs that divide the platforms into two parts at Temple Meads station will in future be divided by proper 'back to back' signals.

Bristol Panel will be abolished and demolished to make way for the new terminating platforms but currently this is planned as a second stage of the project.

It looks as if Swindon Panel will be abolished either in October 2015 or over Xmas/New Year 2015/6.  Watch this space.

[TonyK]

I'm here.......

As always, SandTEngineer, glad you could make it! All is now crystal clear.

[eightf48544]

 The existing 'X' signs that divide the platforms into two parts at Temple Meads station will in future be divided by proper 'back to back' signals.

So someone has recognised that  the markers at Reading are not much good and you need proper signals.

[Louis94]

 The existing 'X' signs that divide the platforms into two parts at Temple Meads station will in future be divided by proper 'back to back' signals.

So someone has recognised that  the markers at Reading are not much good and you need proper signals.

The "markers" you describe at Reading are completely different, merely a car stop marker, guiding where to stop a train returning out of the station the same way and are nothing to do with the signalling.

The 'X' signs at Bristol Temple Meads are classed as signals and may only be passed with the appropriate authority - either a platform number on the indicators outside the station which is beyond the 'X' or permission from the signaller.

[Rhydgaled]

the equipment in the Cogload Junction to Flax Bourton (125mp) area which will not be changed as it is outside of the electrified area.

Did I read that right? A 125mph section which is not included in the scope of the electrification project?

[grahame]

the equipment in the Cogload Junction to Flax Bourton (125mp) area which will not be changed as it is outside of the electrified area.

Did I read that right? A 125mph section which is not included in the scope of the electrification project?

I'm suspecting "Mile Post 125".  Wikipedia says ...

The route has a line speed limit of 100 miles per hour (160 km/h) with local variations; trains from Bristol to Taunton are described as travelling in the 'down' direction. It is constructed to Route Availability 8 and freight loading gauge W8. It has Multiple Aspect Signals (MAS) and Track Circuit Block (TCB^▸ (Track Circuit Block)) controlled from the panel signal box at Bristol. A local signal box at Puxton and Worle controls the two level crossings at Hewish and Puxton, and an emergency panel at Weston-super-Mare can take control of the section from Hewish to Uphill Junction if required.

... which helps to confirm me in making that "Mile Post" rather than "Miles Per Hour" guess.

[Gordon the Blue Engine]

The "markers" you describe at Reading are completely different, merely a car stop marker, guiding where to stop a train returning out of the station the same way and are nothing to do with the signalling.

The 'X' signs at Bristol Temple Meads are classed as signals and may only be passed with the appropriate authority - either a platform number on the indicators outside the station which is beyond the 'X' or permission from the signaller.

I think the point is that the X boards at Reading SHOULD be replaced by proper signals. They are not just a guide or car stop marker - they are mandatory stop positions at the end of their own separate track sections and I think I^m right in saying a train that wrongly passes an X board is treated as a SPAD^▸ (Signal Passed At Danger). 

I see no difference between the Bristol and Reading situations.  As I understand it the X boards at Reading, to quote your words, ^may only be passed with the appropriate authority - either a platform number on the indicators outside the station which is beyond the 'X' or permission from the signaller^.  So just like Bristol.

So why does Bristol get signals and Reading not?

[IndustryInsider]

The 'Rear Clear' markers at Reading are not classed as stop signals and if passed would not be treated as a SPAD^▸ (Signal Passed At Danger).  The indication drivers get at the signal before doesn't alter unless there's a train in any part of the platform in which case they get the 'two white lights' - but could still be required to stop at any part of the unoccupied platform.  There are however 'rules' as to where you stop for each train depending on length and next working of that train.

Very different to Bristol where they are classed as stop signals and the driver does get a platform number to indicate where they should stop.

[SandTEngineer]

the equipment in the Cogload Junction to Flax Bourton (125mp) area which will not be changed as it is outside of the electrified area.

Did I read that right? A 125mph section which is not included in the scope of the electrification project?

Its 125 mile post from London (which is near the site of the closed Flax Bourton station).  I have edited my original post to clarify it.

[Louis94]

The "markers" you describe at Reading are completely different, merely a car stop marker, guiding where to stop a train returning out of the station the same way and are nothing to do with the signalling.

The 'X' signs at Bristol Temple Meads are classed as signals and may only be passed with the appropriate authority - either a platform number on the indicators outside the station which is beyond the 'X' or permission from the signaller.

I think the point is that the X boards at Reading SHOULD be replaced by proper signals. They are not just a guide or car stop marker - they are mandatory stop positions at the end of their own separate track sections and I think I^m right in saying a train that wrongly passes an X board is treated as a SPAD^▸ (Signal Passed At Danger). 

I see no difference between the Bristol and Reading situations.  As I understand it the X boards at Reading, to quote your words, ^may only be passed with the appropriate authority - either a platform number on the indicators outside the station which is beyond the 'X' or permission from the signaller^.  So just like Bristol.

So why does Bristol get signals and Reading not?

To add to what IndustryInsider has said, remember the platform faces at Bristol Temple Meads are longer than those at Reading (some almost 400 metres) and are classed as two separate platforms (Reading having A and B ends of platforms does not count - i'm referring to the Sectional Appendix). Also the platforms at Bristol are used by far more reversing services where there is a potential for a train to already occupying the other end of the platforms, having mid platform signals will mean trains won't need to be cautioned into the station with shunt aspect (two white lights) as is the case in this situation now.

[Gordon the Blue Engine]

I accept what Louise and II say about the status of the X boards at Reading and how they differ from those at Bristol.

However, the fact remains that the Reading signalling design requires frequent permissive moves on P13 and P14 particularly.  Permissive working carries more risks than moves between fixed signals (the relevant Group Standards recognise this), so it is an undeniable fact that "proper" mid platform fixed signals at Reading, and anywhere else where there is permissive platform sharing and where it is physically possible to install them, would be safer and operationally more elegant.   

I^ll now get off this Bristol topic. Reading issues are better discussed under Reading.

[Rhydgaled]

the equipment in the Cogload Junction to Flax Bourton (125mp) area which will not be changed as it is outside of the electrified area.

Did I read that right? A 125mph section which is not included in the scope of the electrification project?

Its 125 mile post from London (which is near the site of the closed Flax Bourton station).  I have edited my original post to clarify it.

Ah, thanks for the clarification.

[johnneyw]

I'll add my thanks for all that interesting information.  Off course there will also be implications for the current side entrance to Temple Meads once the track goes down over what is now part of the public access, short to middle term at least.