Bristol Temple Meads - eastern approach remodelling

[WAO]

Will the layout and infrastructure at the end of this work be mature enough for electrification at least to be planned theoretically?

WAO

 

[edwin_m]

If you look at the track diagrams posted above, one feature that you should take notice of is that there are less points, crossings and crossovers. That’s actually one of the main drivers here, They are not really adding any extra flexibility, they want to simplify the layout so that there are less points and crossings to maintain.

In terms of capacity, although adding the sixth running line will help, its actually not very common to see the existing five lines being used simultaneously anyway. Typically you usually only see three simultaneous movements at any one time. Indeed around ten years ago a track circuit failure closed part of the middle line (Down Filton Main) between the gantry and the platforms and the signaller managed to run every train around it without any significant delay being caused.

Thanks for the update. Do you have any news on future speeds through this junction? Other remodellings and simplifications such as York have increased speeds, which compensates for removal of pointwork to some extent because trains occupy the junctions for less time.

 

[Annetts key]

Thanks for the update. Do you have any news on future speeds through this junction? Other remodellings and simplifications such as York have increased speeds, which compensates for removal of pointwork to some extent because trains occupy the junctions for less time.

No. It was several years ago when I last saw the proposed plan, and I’ve not yet seen the current plan.

At the moment, the speed drops from 90 MPH to 25 MPH between where the main lines pass Kingsland Road sidings (at signals BL1981/BL1983). It’s similar on the Filton lines, but here the speed changes from 40 MPH down to 25 MPH just past signal BL1821 and just past signal BL1823.

All running lines through Bristol East junction are 25 MPH through to the platforms. Platforms 13 and 15 are 15MPH because these used to be non-passenger lines (minimum alterations were done to bring them into passenger use). Platforms 3/4, 5/6, 7/8, 9/10 and 11/12 have a lower speed limit to mitigate against drivers passing the mid platform signals.

The up through and down through are 25 MPH.

When I know more, I’ll post details.

 

[Bald Rick]

Will the layout and infrastructure at the end of this work be mature enough for electrification at least to be planned theoretically?

WAO

It’s designed for electrification

 

[DynamicSpirit]

Depends which bit of the layout you mean.

Without getting too pedantic about the precise shape and orientation of a very curved station, the highest-numbered platforms on the 'south' side obviously feed into the classic GWR route via Bath.

The 'middle' platforms feed into the 'eastern' set of lines up Filton Bank following the recent re-quadrupling. These are the ones that give access to Bristol Parkway.

The low-numbered platforms on the 'north' side (and potentially the Old Station) feed into the western pair of tracks up Filton Bank towards South Wales and Severn Beach.

It would seem perverse to deconflict and parallelise the East Junction layout and then have regular services crossing the majority of it un-necessarily to/from the Old Station.

Coming slightly late to this. I've I've understood that correctly, it means that after the work, essentially the only conflicts East of the station will be the trains that come from Southampton/Weymouth and then head back out towards Cardiff/Gloucester, as there's no way to avoid those crossing over several tracks, right?

Out of interest, what about West of the station? You'll have trains heading out towards Weston Super Mare coming from all of Bath/Bristol Parkway/Cardiff, so there must be presumably be some conflicting moves involved in getting them on to the same tracks. Is that a serious issue?

 

[Bald Rick]

Out of interest, what about West of the station? You'll have trains heading out towards Weston Super Mare coming from all of Bath/Bristol Parkway/Cardiff, so there must be presumably be some conflicting moves involved in getting them on to the same tracks. Is that a serious issue?

Not at all, there’s only 5 trains an hour at most, often only 3. Even when the Portishead branch opens it will be easily dealt with.

 

[SouthStand]

Yes if only someone could have predicted this pandemic when the work was planned nearly 3 years ago.

I nother News, there are only so many resources to deliver this type of work - particularly signalling testers, heavy cranes and wagons for switch and crossings, and the switch and crossing manufacturing capacity. And that is all taken up with Kings Cross which is happening now.

There's no need for sarcasm, he made a good point. It's a shame the work couldn't have been brought forward.

 

[edwin_m]

There's no need for sarcasm, he made a good point. It's a shame the work couldn't have been brought forward.

It's a shame but it's understandable when the issues involved are thought through. Several enhancements have had to be put back because extra social distancing measures have affected the ability to work on site.

 

[Annetts key]

Out of interest, what about West of the station? You'll have trains heading out towards Weston Super Mare coming from all of Bath/Bristol Parkway/Cardiff, so there must be presumably be some conflicting moves involved in getting them on to the same tracks. Is that a serious issue?

Going West from T.M. station, once all the platform lines merge, you have the Down main, the Up Main (which is reversible through to Bedminster station) and the Up Relief.

When there is a down fast/through train, either it goes down the DM or reversible down the UM, the down stopping/local service then goes down the other line with up trains using the UR.

The only problem is when trains are late, then one may have to wait in order for another to do a ladder move to cross over the junction. E.g. when a London Padd. is booked to platform 15.

In the Network Rail ‘wish list’ is the reinstatement of the Down Relief (which is currently the carriage line between West Gantry and Bedminster station, the rest through to South Liberty having been lifted).

If/when this gets funding, the intention is to reinstate the DR to Parson Street. But don’t hold your breath, as I’m not expecting this to happen in the next five years...

 

[Ashley Hill]

Going West from T.M. station, once all the platform lines merge, you have the Down main, the Up Main (which is reversible through to Bedminster station) and the Up Relief.

When there is a down fast/through train, either it goes down the DM or reversible down the UM, the down stopping/local service then goes down the other line with up trains using the UR.

The only problem is when trains are late, then one may have to wait in order for another to do a ladder move to cross over the junction. E.g. when a London Padd. is booked to platform 15.

In the Network Rail ‘wish list’ is the reinstatement of the Down Relief (which is currently the carriage line between West Gantry and Bedminster station, the rest through to South Liberty having been lifted).

If/when this gets funding, the intention is to reinstate the DR to Parson Street. But don’t hold your breath, as I’m not expecting this to happen in the next five years...

The reinstatement of the DR to the other side of Parson Street would be so useful. Stoppers could be left to run rather than be held on either line at Bedminster.

 

[tel]

On the BLS site it also says services could be diverted via St Phillips Marsh during the closures, hopefully this will happen as i need to do that line.

Tel

 

[Tom Quinne]

On the BLS site it also says services could be diverted via St Phillips Marsh during the closures, hopefully this will happen as i need to do that line.

Tel

The through line at SPM is network rail track vice GWR so in theory at least you could run a train through there.

 

[Annetts key]

The lines to/from/via St Phillips Marsh (SPM) are not classified as passenger grade lines. They are classed as sidings. Further, what signalling there is, is controlled not by Network Rail signallers, but by GWR depot staff. So in order for any passenger train to run via SPM, special arrangements would need to be properly planned and documented, and then be correctly implemented.

 

[tel]

The lines to/from/via St Phillips Marsh (SPM) are not classified as passenger grade lines. They are classed as sidings. Further, what signalling there is, is controlled not by Network Rail signallers, but by GWR depot staff. So in order for any passenger train to run via SPM, special arrangements would need to be properly planned and documented, and then be correctly implemented.

Ahh thanks for that, i understand now that probably isn't going to happen, think I'll keep that week spare though 'just in case' something changes like the line is upgraded, unlikely i know but you never know.

Tel

 

[Ashley Hill]

Indeed,the BLS site suggested that the Bristol PW-Weston/Taunton stoppers could be routed via SPM.

 

[MarkyT]

The lines to/from/via St Phillips Marsh (SPM) are not classified as passenger grade lines. They are classed as sidings. Further, what signalling there is, is controlled not by Network Rail signallers, but by GWR depot staff. So in order for any passenger train to run via SPM, special arrangements would need to be properly planned and documented, and then be correctly implemented.

While points can be clipped and secured etc, I suspect the biggest difficulty in safely authorising passenger movements will be the lack of any trapping protection from most of the sidings on the south side of the single line, the HST Sidings and Marsh Lane Depot.

 

[Annetts key]

While points can be clipped and secured etc, I suspect the biggest difficulty in safely authorising passenger movements will be the lack of any trapping protection from most of the sidings on the south side of the single line, the HST Sidings and Marsh Lane Depot.

Well, there are things that could be done, but it would cripple the train maintenance operations at SPM during the time that any arrangements were in place.

 

[edwin_m]

Well, there are things that could be done, but it would cripple the train maintenance operations at SPM during the time that any arrangements were in place.

I guess it could be done for two short periods each night as the sleepers pass, but surely easier to run them via Westbury?

 

[MarkyT]

Well, there are things that could be done, but it would cripple the train maintenance operations at SPM during the time that any arrangements were in place.

Yes, that occurred to me too. As shown in the linked notice, the original layout on Bristol Panel was much easier to use for diversions, with each group of sidings trapped and separately accessed via individual ground frames, but that was heavily hacked about with for the HST depot and sidings project ISTR.

https://www.signallingnotices.org.uk/scans/55/1970%20-%20S%202659%20Bristol%20Stage%204.pdf

Notice to Trainmen, etc.
MULTIPLE ASPECT SIGNALLING
BRISTOL (Stage 4.-North Somerset Junction to Keynsham East and St. Philip's Marsh)
SATURDAY, 18th JULY TO MONDAY, 20th JULY, 1970

 

[Tom Quinne]

The lines to/from/via St Phillips Marsh (SPM) are not classified as passenger grade lines. They are classed as sidings. Further, what signalling there is, is controlled not by Network Rail signallers, but by GWR depot staff. So in order for any passenger train to run via SPM, special arrangements would need to be properly planned and documented, and then be correctly implemented.

Yes, hence the in theory - it is are NWR track though the through line that is controlled from the infamous “Wendy House”.

 

[D6975]

When did the line cease to be a passenger graded line? During the 1980s arriving loco hauled Weston/Taunton stoppers used to routinely go round the loop to avoid the need for run round at TM before heading west again. HSTs with windscreen wiper/horn/speedo faults used to be sent west via the Marsh to put a 'good' PC on the front too.

 

[Annetts key]

I think it was around 1989/1991 or thereabouts when the main two ground frames were replaced with the “Wendyhouse” and clamp lock points were brought into use to work the remodelled depot. That was when Bristol Panel lost control of the line and it was then no longer considered a through line.

 

[MarkyT]

I think it was around 1989/1991 or thereabouts when the main two ground frames were replaced with the “Wendyhouse” and clamp lock points were brought into use to work the remodelled depot. That was when Bristol Panel lost control of the line and it was then no longer considered a through line.

The 'clamp lock' mechanisms are the special 'trailable' variants developed for siding applications, aren't they? I don't think they can legally be used for facing passenger movements without additional safeguards as they lack the complete FPL-equivalent clamp mechanism.

 

[Annetts key]

The 'clamp lock' mechanisms are the special 'trailable' variants developed for siding applications, aren't they? I don't think they can legally be used for facing passenger movements without additional safeguards as they lack the complete FPL-equivalent clamp mechanism.

No, clamp lock is the common name for RCPL - Rail Clamp Point Lock, which have an arm that clamps the switch rail to the stock rail, and this provides the facing point lock function. A power pack (electricity operated hydraulic pump unit) operates two hydraulic rams, one to move the point one way (‘normal’) and another to move the point the opposite way (‘reverse’). Clamp locks are not run-through-able because of the clamp that does the lock function.

Originally SPM HST Depot (as the ‘Wendyhouse” is officially known) had all but one of the power operated points worked by clamp locks.

The other point, ironically right outside the small Wendyhouse, was a run-through-able hydraulic point. It did not have clamp lock bodies, instead it only had electric detection plus two hydraulic pressure sensors. Unfortunately, only a limited number of spares were provided. The company that GWR uses for maintenance gave up with it. So it is now also a clamp lock.

The other two worked points ‘round the Marsh’ were not controlled by the ‘Wendyhouse’, but were still controlled by Bristol Panel. One was a HW point machine at the North Somerset end (near the undercarriage wash plant). The other was the last ground frame, this was at the West end, near Albert Road viaduct (released from Bristol Panel).

Since then, about four years ago, and as part of the pre-work for TVSC taking over Bristol Panel, the control of the HW point machine has been transferred to the new Wendyhouse ‘panel’ (they put another REB on top of the existing relay room REB). And the GF at the west has been converted to a power operated point (I don’t know what type) and also is now controlled by the new Wendyhouse.

The issues with trying to run passenger trains are both rather simple and complex. There are no main aspect routes (only subsidiary aspects) into and through SPM and hence only simple interlocking, there are no trap points, no point to point locking or flank protection, no AWS or TPWS, and the Wendyhouse ‘panel’ as I said above, is not worked by Network Rail signallers.

 

[Western Sunset]

As an aside, I wonder if Gipsy Patch Road will open for vehicular traffic before the summer?

 

[MarkyT]

No, clamp lock is the common name for RCPL - Rail Clamp Point Lock, which have an arm that clamps the switch rail to the stock rail, and this provides the facing point lock function. A power pack (electricity operated hydraulic pump unit) operates two hydraulic rams, one to move the point one way (‘normal’) and another to move the point the opposite way (‘reverse’). Clamp locks are not run-through-able because of the clamp that does the lock function.

Originally SPM HST Depot (as the ‘Wendyhouse” is officially known) had all but one of the power operated points worked by clamp locks.

The other point, ironically right outside the small Wendyhouse, was a run-through-able hydraulic point. It did not have clamp lock bodies, instead it only had electric detection plus two hydraulic pressure sensors. Unfortunately, only a limited number of spares were provided. The company that GWR uses for maintenance gave up with it. So it is now also a clamp lock.

The other two worked points ‘round the Marsh’ were not controlled by the ‘Wendyhouse’, but were still controlled by Bristol Panel. One was a HW point machine at the North Somerset end (near the undercarriage wash plant). The other was the last ground frame, this was at the West end, near Albert Road viaduct (released from Bristol Panel).

Since then, about four years ago, and as part of the pre-work for TVSC taking over Bristol Panel, the control of the HW point machine has been transferred to the new Wendyhouse ‘panel’ (they put another REB on top of the existing relay room REB). And the GF at the west has been converted to a power operated point (I don’t know what type) and also is now controlled by the new Wendyhouse.

The issues with trying to run passenger trains are both rather simple and complex. There are no main aspect routes (only subsidiary aspects) into and through SPM and hence only simple interlocking, there are no trap points, no point to point locking or flank protection, no AWS or TPWS, and the Wendyhouse ‘panel’ as I said above, is not worked by Network Rail signallers.

Yes I understand what a clamp lock is, derived from SNCF designs originally I remember, and I realise the name derives from the clamping arm mechanism, without which any related actuator wouldn't really be a clamp lock at all. However I remember from my late 80s or early 90s period in the drawing office that some work was being done by another section to design an implementation of a cut-down siding point actuator based on many of the same parts, so perhaps that was the single abortive example you refer to? I concur it's probably impossibly difficult practically to run more than a handful of passenger trains through SPM today, certainly not something you'd want to do all weekend with the impact on servicing and maintenance activity at a time when much of the fleet would normally be in. Note there are many non-passenger yard point actuator products available from various manufacturers today, and centralised control of points is becoming more popular in modern UK depot and yard layouts.

 

[Annetts key]

Yes I understand what a clamp lock is...

Sorry, I got a bit carried away! I did think it strange that you did not know about them, but...
Anyway...

However I remember from my late 80s or early 90s period in the drawing office that some work was being done by another section to design an implementation of a cut-down siding point actuator based on many of the same parts, so perhaps that was the single abortive example you refer to?

Yes, it used the same power pack as a clamp lock, the same hydraulic rams (although because there were no clamp lock bodies, it used different fixings to the switch rails). When first installed, it worked well. The main problem was that it used a hydraulic valve to feed from whichever was the pressurised line (normal or reverse) to the two hydraulic pressure sensors. One sensor (at 60 bar IIRC) activated the pump motor if the pressure dropped too low. The second (at 50 bar IIRC) dropped out the electric detection if the pressure dropped below 50 bar. The first problem was, dirt and wear in the valve caused fluid to leak from the pressurised line to the unpressurised line. This caused the pump to run frequently instead of intermittently. The second problem was that over time, the pressure switches drifted away from the correct pressure points. When combined, the result was that the pressure dropped too fast, and before the pump could run and build up enough pressure, the detection would drop out. Hence drivers kept reporting the position light signals flashing between off and on...

 

[Envoy]

‘The Architecture The Railways Built’ on Yesterday channel (Free on all platforms) will include Bristol Temple Meads tonight (Tuesday 9 March, 2021) at 8pm.

 

[Horizon22]

Crosscountry's advice regarding the closures in Summer - https://www.crosscountrytrains.co.uk/travel-updates-information/bristol-temple-meads-2021

 

[Yindee8191]

Crosscountry's advice regarding the closures in Summer - https://www.crosscountrytrains.co.uk/travel-updates-information/bristol-temple-meads-2021

‘Journey times extended by 10 minutes’ certainly makes it sound like they’ll be routing trains through St Philip’s Marsh. Surely there’s no other alternative route that would only take an extra 10 minutes?