HS2 and the next Prime Minister

6Gman · 27 May 2019

Robertj21a said:
If he develops an ongoing party it's quite possible that he will end up in a coalition. HS2 could be a sacrificial cow.

It could be.

Or it might not.

RailUK Forums

Meole · 27 May 2019

Londerground said:
HS2 is the biggest fraud ever. So called 'Climate change' believers can't even plant trees. What a s*** shower it has become. Besides c-lie-mate change being a hoax, they can't even properly implement projects to fulfil their so called 'green' aims. A spiralling budget etc. amongst the mounting problems, with growing opposition all the time.

HS2 is doomed.

With the Brexit party on an unstoppable rise, any HS2 mp is in the firing line at the next election.

Plus as other posters have said, people are leaving cities, work patterns are changing. Railway passenger numbers have been falling since 2017.

Interesting to note that passenger numbers are dropping year on year, that doesn't seem to be the case on Birmingham/London which on my regular journeys seems to be a commuter line now, perhaps property prices are lower around Birmingham, anyway at peak periods seats are at a serious premium. I suppose Crossrail will also struggle to attract custom as Londoners will also use Skype to avoid travel.

CanalWalker · 28 May 2019

The Ham said:
I would suggest that the numbers traveling between Bournville and Wimbledon are likely to be faily small, given that Bournville had about 1 million passengers a year.

However there's still likely to be some time saving for anyone who does make that trip, even though it's not as large as it could be.

However even if someone were to opt for using the via New Street service with a few extra stops enroute there would be more space for them and they may be able to our to go via Watford Junction rather than via Euston.

Either way chances are they will see some benefit.

Bournville was just a name out of a hat. The point is that most journeys are made from suburbs to suburbs rather than just between mainline stations. Which reduces the percentage time saving.

CanalWalker · 28 May 2019

jagardner1984 said:
In terms of when is it too late, as I recall the Channel 4 documentary had actual fencing being placed around actual properties, by actual people in hi vis jackets. It certainly felt pretty real.

I think the pro-rail voices need to refocus the discussion away from speed and onto capacity. I’m sure an interesting chart of percentage of theoretical peak capacity (in terms of signalling / platform length / current operated train length) in current major termini might be informative for people.

I also wonder whether something like the Principle of the Barnett Formula, which links spending in London to additional spending in Scotland, could be used to negate the “i live in Plymouth, what have HS2 ever done for me” brigade.

Unless HS2 is repeated every 10 years for the next century, the infrastructure challenges of today will only grow.

This really belongs in "Speculative Ideas" where it has probably already been discussed but ....

Surely the best way to increase capacity is not to lay more steel but to make better use of the existing metal by running trains closer together. The current block system of working is Victorian. Money would be better spent on developing a modern control system that allows trains to run with a few seconds separation rather than a few minutes.

squizzler · 28 May 2019

I will be terribly disappointed if the next prime minister fails to personally authorise my plans for a Great Western HSR network and drives the line right through Jacob Rees Mogg's family estate.

The Ham · 28 May 2019

CanalWalker said:
This really belongs in "Speculative Ideas" where it has probably already been discussed but ....

Surely the best way to increase capacity is not to lay more steel but to make better use of the existing metal by running trains closer together. The current block system of working is Victorian. Money would be better spent on developing a modern control system that allows trains to run with a few seconds separation rather than a few minutes.

Serious question, what happens if a train derails and the following train can't stop fast enough when it's traveling at 125mph?

The Ham · 28 May 2019

Meole said:
Interesting to note that passenger numbers are dropping year on year, that doesn't seem to be the case on Birmingham/London which on my regular journeys seems to be a commuter line now, perhaps property prices are lower around Birmingham, anyway at peak periods seats are at a serious premium. I suppose Crossrail will also struggle to attract custom as Londoners will also use Skype to avoid travel.

The problem is that the data doesn't support the "fact" that growth is falling:
http://dataportal.orr.gov.uk/browsereports/15

Between 2016/17 and 2017/18 growth between London and the West Midlands was 2.2% bringing the total since 2010/11 to 47% growth, this is higher than the HS2 predictions for the high growth rate of 5%/year to 2026. It is significant higher than the 2.5% growth used to justify the building of HS2.

Ken H · 28 May 2019

CanalWalker said:
Bournville was just a name out of a hat. The point is that most journeys are made from suburbs to suburbs rather than just between mainline stations. Which reduces the percentage time saving.

I used to commute between a south warwickshire village and wimbledon 1 day a week. Looked at the train (Warwick Pwy- Wimbledon) but it took a long long time cos of crossing London. So I drove. A colleague did the same from a SE brum suburb and came to the same conclusion.

GreatAuk · 28 May 2019

CanalWalker said:
This really belongs in "Speculative Ideas" where it has probably already been discussed but ....

Surely the best way to increase capacity is not to lay more steel but to make better use of the existing metal by running trains closer together. The current block system of working is Victorian. Money would be better spent on developing a modern control system that allows trains to run with a few seconds separation rather than a few minutes.

This is exactly the sort of 'why not just...' sentiment based on a massive lack of understanding which I worry may be directed at both Network Rail and HS2 should certain politicians get into power. Sadly I imagine that many of the politicians that come out with things like this are actually fairly well aware of how unrealistic they are being, but go ahead anyway just because they dislike railways for ideological reasons.

On a practical level, while modern moving block signalling systems could massively improve capacity on many lines (perhaps the West Coast Main Line less than many though due to the relatively modern existing signalling and nature of the traffic...), there are fundamental limits to what can be achieved without abandoning principles such as:
- Proving that points have successfully changed position before routing a train over them, making sure your train doesn't derail or get misrouted.
- Ensuring that trains can stop in sufficient time to avoid a collision if the train in front derails / crashes into something.

Also should be considered there's not much point running trains 'seconds' apart on the same line when intercity trains are likely to need at least a minute to stop at each station.

I'm sure there are lots of other reasons this wouldn't work too but those are the key ones which come to mind.

Wivenswold · 28 May 2019

Anyone who thinks that Climate Change isn't happening needs to start listening to scientists instead of appropriating others people's ill-informed, ignorant ideologies.
As an amateur Meteorologist I can't profess to be a climate expert but I can report from my own observations that there have been significant changes in weather patterns in the last 5 years that should be a huge concern for everyone.

Sadly climate change denial has become a staple of the agenda for Populist Far-right figures, whose popularity is an insult to the memory of anyone who gave their lives in WWII fighting the last far-right uprising. Which makes the attachment of "patriotism" to the cause even more farcical.

underbank · 28 May 2019

The Ham said:
Serious question, what happens if a train derails and the following train can't stop fast enough when it's traveling at 125mph?

Obviously "a few seconds" is extreme and probably completely unrealistic, but if, say, there's a 4 minute gap due to block working, then electronic/internet control could maybe reduce that to 2 minutes without impacting too seriously on safety. Bearing in mind current block signalling doesn't prevent all accidents anyway.

What proportion of railway journeys does a catastrophic derailment event happen on? Across the network, it's it once a week, once a month, once a year, once a decade? What frequency is an acceptable risk?. Is it that much different when a single 11 coach pendolino comes off the tracks as opposed to two 4 coach voyagers where the one behind doesn't manage to stop in time after the front one comes off and there's a relatively slow speed collision, if the numbers of injuries/fatalities are similar in both scenarios?

An "emergency stop" without a derailment is different. If the trains are "talking" to eachother electronically, the train behind could slam on it's brakes just a few millioseconds after the one in front, so would both brake harshly together, so no reason why the one behind would collide with the one in front. (Distances between trains could be automatically calculated with regard to stopping distance according to type of train, length, weight etc., so a light engine needs much less distance than a 20 truck granite train.

underbank · 28 May 2019

GreatAuk said:
Also should be considered there's not much point running trains 'seconds' apart on the same line when intercity trains are likely to need at least a minute to stop at each station.

But if they're closer together between stations on the main line, they'll clear junctions etc quicker to allow joining/leaving trains onto the main line quicker, thus helping avoid congestion at the "pinch points". There are scenarios when it's better to have the following train waiting behind the one in front to access a station, to allow the tracks/junctions/crossovers behind to be clear for other services to proceed.

There's no "one size fits all", but at least with a more modern signalling/control system, there'd be flexibility to run trains closer together when the circumstances warranted it, and there'd still be the ability to keep trains as separate as they are today too when necessary.

It would also help enormously on branch lines (and lesser used main lines) with long "blocks" where there can be massive delays waiting for a train ahead to clear a very long block.

DynamicSpirit · 28 May 2019

underbank said:
Obviously "a few seconds" is extreme and probably completely unrealistic, but if, say, there's a 4 minute gap due to block working, then electronic/internet control could maybe reduce that to 2 minutes without impacting too seriously on safety. Bearing in mind current block signalling doesn't prevent all accidents anyway.

What proportion of railway journeys does a catastrophic derailment event happen on? Across the network, it's it once a week, once a month, once a year, once a decade? What frequency is an acceptable risk?. Is it that much different when a single 11 coach pendolino comes off the tracks as opposed to two 4 coach voyagers where the one behind doesn't manage to stop in time after the front one comes off and there's a relatively slow speed collision, if the numbers of injuries/fatalities are similar in both scenarios?

An "emergency stop" without a derailment is different. If the trains are "talking" to eachother electronically, the train behind could slam on it's brakes just a few millioseconds after the one in front, so would both brake harshly together, so no reason why the one behind would collide with the one in front. (Distances between trains could be automatically calculated with regard to stopping distance according to type of train, length, weight etc., so a light engine needs much less distance than a 20 truck granite train.

I'm not sure how this is planned to work on HS2 - or how it actually works on existing high speed lines in other countries. But a quick calculation says that, with the plans for HS2 to run 18 tph, that means trains will usually be about 3 minutes apart. At 120mph, that's 6 miles between trains. At 200mph that's roughly 10 miles between trains. So, if the trains are communicating their positions and speeds to each other electronically, that would appear to give more than ample space for trains to slow down to comfortably avoid collisions.

JamesT · 28 May 2019

DynamicSpirit said:
I'm not sure how this is planned to work on HS2 - or how it actually works on existing high speed lines in other countries. But a quick calculation says that, with the plans for HS2 to run 18 tph, that means trains will usually be about 3 minutes apart. At 120mph, that's 6 miles between trains. At 200mph that's roughly 10 miles between trains. So, if the trains are communicating their positions and speeds to each other electronically, that would appear to give more than ample space for trains to slow down to comfortably avoid collisions.

From the table in http://www.railway-technical.com/books-papers--articles/high-speed-railway-capacity.pdf it suggests you need 10km (6.2 miles) to stop from 360kph (220mph). The preceding train isn't going to suddenly be at 0, but it does suggest you need a fairly large chunk of that 10 miles to provide a safe buffer between trains.

underbank · 28 May 2019

JamesT said:
From the table in http://www.railway-technical.com/books-papers--articles/high-speed-railway-capacity.pdf it suggests you need 10km (6.2 miles) to stop from 360kph (220mph). The preceding train isn't going to suddenly be at 0, but it does suggest you need a fairly large chunk of that 10 miles to provide a safe buffer between trains.

Is that normal breaking or emergency stop braking?? But unless the train in front stops dead by hitting an immovable object, it, too, will travel a fairly long way whilst it comes to a stop. If electronic communication means they both apply the emergency brake at the same time, the distance between them won't reduce as they both come to rest (unless they are of different size/weight/brake power etc).

MarkyT · 28 May 2019

This paper covers all the issues surrounding capacity and braking distance and suggests that on a railway like HS2 a technical headway between train fronts of 12,300m is required.
http://www.railway-technical.com/books-papers--articles/high-speed-railway-capacity.pdf

Train Separation

...This gives us a total separation distance between successive train fronts of 12300m (Figure 2). If two trains, both running at 360km/h were following each other at this distance, they would be 123s apart. This may be defined as the full speed, signalled headway, sometimes referred to as the “technical headway”. Thus, if all trains ran along the line at this speed and separation, the line could be said to have a capacity of 29.27 trains per hour. However, there are a number of issues that will reduce this number and I consider these next...

The paper goes on to explain why 29 trains an hour is not a reasonable figure covering the headings: Braking Management, Intermediate Stations and their mitigation by loops, and Operational Headways

Operational Headways
So far, this discussion has been limited to technical headways. The technical headway is the theoretical headway offered by the train and its control system. It is never achieved in practice. Since
it cannot be expected that a train will arrive at the exact point allowed by the control system at the moment it becomes available, a system designer must recognise that a margin for operational
variances must be allowed for. This margin is additional to those already included above, like driver sighting, data transmission and equipment response times. This margin covers such things as
variable dwell times, varying train performance, variable traction voltages, variable driver performance, weather, temporary speed restrictions and some sort of recovery margin.
The UIC recommends that 75% of technical headway is as good as can be obtained for operational throughput. In our example, this would give an operational headway of 16 trains per hour, assuming the most restrictive technical headway at the converging junction as offered by McNaughton (2011). This is close to the MVA/Systra model (2011) where 16.6 tph is proposed at 350km/h. This model includes the 20s “driving allowance”, which could be reduced with some level of automation. Nevertheless, the conclusion here is that 16 tph is a sensible capacity for a high speed rail system of the type proposed by HS2.
Dwell Times
A large part of operational variability in high capacity rail systems is caused at stations. Dwell times at stations are notoriously difficult to control, particularly under European conditions, where passenger discipline is not as good as it is in, say, Japan. While we are wandering about looking for the carriage where we think our allocated seat might be, dragging our HGV-sized bags, luxury pushchairs and screaming children up and down the platform, the next train is catching up - at 360km/h. So the dwell time at an intermediate station has to be limited, in this case I would suggest, to three minutes. Systra note that the dwell time at airport stations is fixed at 5 minutes on TGV routes to allow for the additional baggage carried by passengers. This would almost certainly have to be considered for HS2 at Old Oak Common and Birmingham Interchange.

Note the figure recommended here is slightly less than the 18tph actually proposed, but the author also notes in the text that automation of the driving function can bring some benefit, and that is likely to be a feature of the new rolling stock, at least for driving on the new infrastructure. The actual method of signalling and whether it incorporates fixed or moving blocks makes very little difference to all these calculations, although of course at the kind of speeds involved, trackside colour light signals are not at all appropriate, so all indications and data sufficient for safe manual or automatic control must be brought into the cab environment.

QueensCurve · 28 May 2019

Typhoon said:
They could offer to call it The Boris Line. It will get a thumbs up from him then!

Serious point - does it run through any of their constituencies? Sorry too many definites and maybes to check.

The Alexander Boris De Pfeffel Johnson Line has a sort of ring to it.

CanalWalker · 29 May 2019

underbank said:
Obviously "a few seconds" is extreme and probably completely unrealistic, but if, say, there's a 4 minute gap due to block working, then electronic/internet control could maybe reduce that to 2 minutes without impacting too seriously on safety. Bearing in mind current block signalling doesn't prevent all accidents anyway.

What proportion of railway journeys does a catastrophic derailment event happen on? Across the network, it's it once a week, once a month, once a year, once a decade? What frequency is an acceptable risk?. Is it that much different when a single 11 coach pendolino comes off the tracks as opposed to two 4 coach voyagers where the one behind doesn't manage to stop in time after the front one comes off and there's a relatively slow speed collision, if the numbers of injuries/fatalities are similar in both scenarios?

An "emergency stop" without a derailment is different. If the trains are "talking" to eachother electronically, the train behind could slam on it's brakes just a few millioseconds after the one in front, so would both brake harshly together, so no reason why the one behind would collide with the one in front. (Distances between trains could be automatically calculated with regard to stopping distance according to type of train, length, weight etc., so a light engine needs much less distance than a 20 truck granite train.

Thank you for a response to my post that is both reasoned and, inoffensive, unlike another reply.

CanalWalker · 29 May 2019

The Ham said:
Serious question, what happens if a train derails and the following train can't stop fast enough when it's traveling at 125mph?

To answer that I would need to know
a) how quicky a derailed train comes to rest.
b) how long it takes to stop a 125mph train.

And in the greater scheme we would have to consider what is the likelyhood of a train derailing in front of another travelling at 125mph?
What level of risk are you prepared to accept?

MarkyT · 29 May 2019

CanalWalker said:
To answer that I would need to know
a) how quicky a derailed train comes to rest.
b) how long it takes to stop a 125mph train.

And in the greater scheme we would have to consider what is the likelyhood of a train derailing in front of another travelling at 125mph?
What level of risk are you prepared to accept?

Traditionally in the railway industry, none whatsoever and rightly so in my opinion because the tremendous forces and the operational implications of even a 'minor shunt'. There is always at least a complete braking distance maintained between services so a following train can can be relied upon to come to a stand before it could encounter any wreckage from an incident ahead, assuming the control system has detected that the line hasn't become clear ahead. With axle counters, even if the derailed train has completely left the rails it will not be counted out at the far extremity of a train detection section, so a signal to rear (or its digital equivalent) will remain at danger and trains behind will stop gently on a full service brake application.

The Ham · 29 May 2019

MarkyT said:
Traditionally in the railway industry, none whatsoever and rightly so in my opinion because the tremendous forces and the operational implications of even a 'minor shunt'. There is always at least a complete braking distance maintained between services so a following train can can be relied upon to come to a stand before it could encounter any wreckage from an incident ahead, assuming the control system has detected that the line hasn't become clear ahead. With axle counters, even if the derailed train has completely left the rails it will not be counted out at the far extremity of a train detection section, so a signal to rear (or its digital equivalent) will remain at danger and trains behind will stop gently on a full service brake application.

Given the harm which is caused when a person leaves a car which had been traveling at 30mph I would suggest that it would need to be much slower than that.

Given that stopping distances aren't straight lines then by the time you've allowed a train to get down to (say) 10mph the extra distance saved to get it down to 0mph isn't really worth the risk.

As a example the stopping distance for road design for a car traveling at 30mph is 40m whist it's 9m from 10mph. It's it really worth risking the harm which could be caused at 10mph (which is likely to be fairly minor for most but not all) for the sake of 9m when you've already allowed 31m? (Actually it's less than 9m as that includes reaction time which has already been accounted for).

underbank · 29 May 2019

CanalWalker said:
And in the greater scheme we would have to consider what is the likelyhood of a train derailing in front of another travelling at 125mph? What level of risk are you prepared to accept?

And talking of distance between trains travelling in the same direction doesn't even begin to look at the consequences of a derailment that causes part of a train into the path of an oncoming train in the other direction. So, you can't eliminate all risk. Having excessive stopping distances only removes the chances of certain types of collision, not all possibilities.

Eg having a following train 3 blocks behind the pendolino at Grayrigg wouldn't have helped had there been a southbound pendolino just one block away at the time of the derailment.

Zero risk isn't possible. Especially when it comes to derailments where there's more likelihood of being hit by a train coming the opposite way than there is of one from behind.

6Gman · 29 May 2019

underbank said:
Is that normal breaking or emergency stop braking?? But unless the train in front stops dead by hitting an immovable object, it, too, will travel a fairly long way whilst it comes to a stop. If electronic communication means they both apply the emergency brake at the same time, the distance between them won't reduce as they both come to rest (unless they are of different size/weight/brake power etc).

"If".

Since we seem to find it difficult - and sometimes impossible - to operate on-train reservation systems, or achieve effective wi-fi on many trains the idea of my safety depending on instantaneous electronic communication between moving trains is unappealing.

Think I'll stick to block working thank you.

MarkyT · 29 May 2019

So called moving block systems of the future will not actually increase capacity on the main line railway system significantly. For trains following each other at linespeed on plain track, today's fixed block techniques actually get as close as possible to the theoretical maximum already. Cab based systems such as ETCS L2 or TVM430 use fixed train detection blocks with marker boards as stopping targets in place of signals. Because the safe speed and braking envelope is being calculated on board, block length between markers is no longer so explicitly related to braking distance so block lengths can be varied more easily to increase resolution according to local factors. The most important factor determining total plain line capacity on high density railways is the platform reoccupation time which is closely related to dwell time, but also to how close in you can bring the NEXT train to the platform to wait for its clearance. With the the more easily variable block lengths of cab signalling 'hold points' much closer to the platform can be provided so trains can keep moving for longer. With colour lights, sometimes the home signal protecting a platform can be as much as a mile away from the platform concerned, although in many cases additional 'closing up' signals are provided for just this purpose. The problem with that is that these signals are comparatively expensive and are often very complex to control as they might be partway through throat junctions and have complex, possibly confusing, aspect sequences displayed involving approach release conditions that can be preempted sometimes by drivers leading to misunderstandings and SPADs. 'Closing up' under fixed block cab signalling can be a much cheaper add-on, and far less confusing because there are no ambiguous indication sequences given, just the safe speed envelope and stopping targets displayed on the cab control screen. The main theoretical advantage of 'moving block' is the removal of much trackside equipment used for train detection, not the removal of the fixed block limits themselves. Hence developments today are concentrating on using ETCS Level 3 techniques to create VIRTUAL fixed blocks between lineside markers that remain. Trains of known length and integrity will position themselves using balises and odometry relative to these fixed positions and report 'tail clear' when appropriate to the control system.

Class 170101 · 2 Jun 2019

underbank said:
And talking of distance between trains travelling in the same direction doesn't even begin to look at the consequences of a derailment that causes part of a train into the path of an oncoming train in the other direction. So, you can't eliminate all risk. Having excessive stopping distances only removes the chances of certain types of collision, not all possibilities.

Eg having a following train 3 blocks behind the pendolino at Grayrigg wouldn't have helped had there been a southbound pendolino just one block away at the time of the derailment.

Zero risk isn't possible. Especially when it comes to derailments where there's more likelihood of being hit by a train coming the opposite way than there is of one from behind.

I would have thought Watford Tunnels would be a better example than Grayrigg where a derailed train did give a 'glancing blow' (thankfully) to a train in the opposite direction.

JohnB57 · 2 Jun 2019

Referring to the original post, Sajid Javid stated on the Andrew Marr Show today that he'd continue to support HS2.

Of course, it's easy to tell when a politician is committing terminological inexactitude and his lips definitely did move when he said it...

700007 · 2 Jun 2019

JohnB57 said:
Referring to the original post, Sajid Javid stated on the Andrew Marr Show today that he'd continue to support HS2.

Of course, it's easy to tell when a politician is committing terminological inexactitude and his lips definitely did move when he said it...

Of course he would, makes it easier for him to get to London from his constituency of Bromsgrove, the suburbs of Birmingham.

CanalWalker · 2 Jun 2019

6Gman said:
"If".

Since we seem to find it difficult - and sometimes impossible - to operate on-train reservation systems, or achieve effective wi-fi on many trains the idea of my safety depending on instantaneous electronic communication between moving trains is unappealing.

Think I'll stick to block working thank you.

Airline reservation systems are also rubbish and their in flight entertainment iffy. But that doesn't stop electronic communication between 'planes and ground and electronic flight control systems making air travel very safe.

CanalWalker · 2 Jun 2019

MarkyT said:
So called moving block systems of the future will not actually increase capacity on the main line railway system significantly. For trains following each other at linespeed on plain track, today's fixed block techniques actually get as close as possible to the theoretical maximum already. Cab based systems such as ETCS L2 or TVM430 use fixed train detection blocks with marker boards as stopping targets in place of signals. Because the safe speed and braking envelope is being calculated on board, block length between markers is no longer so explicitly related to braking distance so block lengths can be varied more easily to increase resolution according to local factors. The most important factor determining total plain line capacity on high density railways is the platform reoccupation time which is closely related to dwell time, but also to how close in you can bring the NEXT train to the platform to wait for its clearance. With the the more easily variable block lengths of cab signalling 'hold points' much closer to the platform can be provided so trains can keep moving for longer. With colour lights, sometimes the home signal protecting a platform can be as much as a mile away from the platform concerned, although in many cases additional 'closing up' signals are provided for just this purpose. The problem with that is that these signals are comparatively expensive and are often very complex to control as they might be partway through throat junctions and have complex, possibly confusing, aspect sequences displayed involving approach release conditions that can be preempted sometimes by drivers leading to misunderstandings and SPADs. 'Closing up' under fixed block cab signalling can be a much cheaper add-on, and far less confusing because there are no ambiguous indication sequences given, just the safe speed envelope and stopping targets displayed on the cab control screen. The main theoretical advantage of 'moving block' is the removal of much trackside equipment used for train detection, not the removal of the fixed block limits themselves. Hence developments today are concentrating on using ETCS Level 3 techniques to create VIRTUAL fixed blocks between lineside markers that remain. Trains of known length and integrity will position themselves using balises and odometry relative to these fixed positions and report 'tail clear' when appropriate to the control system.

Thak you. Very informative. Perhaps moving block would be more appropriate to branch lines with blocks several miles long.
It does seem ludicrous to be held at Furness Vale because a train 5 miles away has not left the Whaley Bridge - Chapel block.

MarkyT · 2 Jun 2019

CanalWalker said:
Thak you. Very informative. Perhaps moving block would be more appropriate to branch lines with blocks several miles long.
It does seem ludicrous to be held at Furness Vale because a train 5 miles away has not left the Whaley Bridge - Chapel block.

Well a few more virtual fixed block divisions might be thrown in very economically on very rural routes to overcome this, but I'm concerned that a fully moving block concept relies on continuous high integrity data radio communication which is often difficult to achieve economically in those same areas. A notional low capacity fixed block 'regional' etcs system would only need radio coverage in the vicinity of the fixed block boundaries for intermittent communication, rather like RETB. Potentially much cheaper and likely to be far more reliable. At the moment even in standard level 2 if you lose the radio signal for a few seconds, movement authority is lost and anchors go in hard. Then it's like a hard reboot to get going again as all the various layers of communications and application protocols and cryptography have to re-establish, which, being safety critical, takes a LONG time. On a busy mainline railway lots of overlapping radio coverage can be built in to mitigate, but in very rural areas it can get unfeasibly expensive relative to the capacity provided. ETCS as envisaged today doesn't scale down very well to rural railways.

HS2 and the next Prime Minister

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