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3 hours ago, St. Simon said:

 

Hi Paul,

 

Yes and no, the Mechanical Semaphores at Lostwithiel, Par and Truro are all being replaced with LED Colour Lights, they will be controlled by a VDU Workstation at Exeter rather than the panel. However, the Mechanical Semaphore Signals at Liskeard, St. Blazey, Goonbarrow and St. Erth will remain and worked by their respective boxes.

 

Simon.

 

Better get down to Losty and get some piccies…….

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2 hours ago, St. Simon said:


Hi Paul,

 

I think it’s down to asset condition and cost.

 

Simon

That explains why it's 'skipping' Liskeard then, but seems a bit strange that a mechanical box will remain between areas controlled from Exeter / Plymouth!

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11 hours ago, Ramblin Rich said:

That explains why it's 'skipping' Liskeard then, but seems a bit strange that a mechanical box will remain between areas controlled from Exeter / Plymouth!

But I guess it’s only a matter of time…….

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I really hope that the S&T get an increase in numbers with failed TCs between Totnes and Plymouth  a daily occurrence and no sign of being fixed before some clever folk try to use 30 year old cables to try and run railways in Cornwall from Exeter - What is  currently available does  work reliably enough in Cornwall and the boxes can cope with failures and keep trains running due to local knowledge and staff on the ground. To try and overlay and recontrol stuff seems foolhardy in the extreme given the abject attempts at emergency working with too few staff on the ground working long 12 hr shifts as a norm so thinly spread as to be barely effective  

 

I guess in time the Plymouth panel will be replaced or recontrolled from Exeter but too much involved at this time  and destroying Cornwall  recontrolling Cornwall is seen as a quicker win in the saving money front for NR/GBR . (penny wise pound foolish springs to mind.)  

 

Robert 

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3 hours ago, Robert Shrives said:

I really hope that the S&T get an increase in numbers with failed TCs between Totnes and Plymouth  a daily occurrence and no sign of being fixed before some clever folk try to use 30 year old cables to try and run railways in Cornwall from Exeter - What is  currently available does  work reliably enough in Cornwall and the boxes can cope with failures and keep trains running due to local knowledge and staff on the ground. To try and overlay and recontrol stuff seems foolhardy in the extreme given the abject attempts at emergency working with too few staff on the ground working long 12 hr shifts as a norm so thinly spread as to be barely effective  

 

I guess in time the Plymouth panel will be replaced or recontrolled from Exeter but too much involved at this time  and destroying Cornwall  recontrolling Cornwall is seen as a quicker win in the saving money front for NR/GBR . (penny wise pound foolish springs to mind.)  

 

Robert 


Hi,

 

Whilst the above maybe true, it’s actually a very small part of the whole story.

 

There’s lots of very good reasons for the resignalling, and actually cost is a very small part of it. (I know I said cost is a factor, but there’s other bigger factors at play, none of which I can reveal)


Everybody is always willing to have a pop at mechanical re-signalling (because it apparently ‘destroys’ the area) , without thinking about  all the factors that have led to that decision, it is not just ‘money saving’ and I’m bored of people thinking that it is the be all and end all. The fact is that the UK really needs to move on from wiggling plates of steel on the end of a bit string to signal trains. I know it works, but it is really limited in what it can do.

 

(Obviously  the above is a personal opinion)

 

Simon

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55 minutes ago, St. Simon said:

UK really needs to move on from wiggling plates of steel on the end of a bit string to signal trains. I know it works, but it is really limited in what it can do.

The UK is probably doing the right thing, its only those of us who are aging just like the signals that need replacing.  But we don't get replaced!:(

    Brian.

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2 hours ago, St. Simon said:

The fact is that the UK really needs to move on from wiggling plates of steel on the end of a bit string to signal trains. I know it works, but it is really limited in what it can do.

Accepting that as a personal opinion here's mine.  

 

Modern electronics can do a great deal that "wiggling plates of steel on the end of a bit of string" cannot but they are not the only answer to safe signalling on the railway.  The more that signalling is centralised in a handful of remote locations the greater the chances of a fairly small glitch causing massive and widespread disruption.  And the greater the chance of the signaller who takes an emergency call not being familiar with the area on the ground.  

 

Were we to attempt to run the current (roughly 90% of full) timetable out of Waterloo with semaphores, block bells and permissive, let alone absolute block working then we would fail.  There are more movements than such a system can cope with.  But Cornwall is in a different league altogether and has only just gained a two-trains-per-hour main line service.  The areas of semaphore signalling can cope perfectly well with this and there is virtually nil chance of any further-enhanced service level being required which might in turn trigger a need for more intensive signalling.  Cornwall is long and thin but benefits from having local knowledge among its signallers and other operational staff meaning trains can usually be kept moving (even if at caution) through a failure.  

 

Scenarios: - Three Bridges ROC now interfaces with York since the closure of Kings Cross.  If a cable fault occurred deep in Sussex it could turn many signals along the East Coast Main Line dark.  A national artery would grind to a halt and train services as far away as Aberdeen and Penzance could be impacted.  A defective pull on Liskeard Down Home will delay nothing by more than a few minutes because the half-hourly train can be flagged past.  And one which happened to me very recently - spotting a trespasser on the line I made an emergency call to the relevant signaller who took the call in Basingstoke but with the words "Signaller Fel ... no .... Strawberry Hill"  Because he was assigned the Strawberry Hill workstation in the ROC which had just taken over from Feltham PSB.  By the time I had described the location and why I needed the traction current discharged the trespasser was attempting to board a train stopped at signals.  Had the local (manual) box still been open the "bobby" should have been able to see the incident and while current discharge would still require a call to the electrical control room it wouldn't have needed five safety-critical minutes of location description first.  

 

Progress where it offers clear benefits is fine.  Where there is no demonstrable need then "if it ain't broken don't fix it".  Other opinions are available.  

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16 hours ago, Gwiwer said:

Accepting that as a personal opinion here's mine.  

 

Modern electronics can do a great deal that "wiggling plates of steel on the end of a bit of string" cannot but they are not the only answer to safe signalling on the railway.  The more that signalling is centralised in a handful of remote locations the greater the chances of a fairly small glitch causing massive and widespread disruption.  And the greater the chance of the signaller who takes an emergency call not being familiar with the area on the ground.  

 

Were we to attempt to run the current (roughly 90% of full) timetable out of Waterloo with semaphores, block bells and permissive, let alone absolute block working then we would fail.  There are more movements than such a system can cope with.  But Cornwall is in a different league altogether and has only just gained a two-trains-per-hour main line service.  The areas of semaphore signalling can cope perfectly well with this and there is virtually nil chance of any further-enhanced service level being required which might in turn trigger a need for more intensive signalling.  Cornwall is long and thin but benefits from having local knowledge among its signallers and other operational staff meaning trains can usually be kept moving (even if at caution) through a failure.  

 

Scenarios: - Three Bridges ROC now interfaces with York since the closure of Kings Cross.  If a cable fault occurred deep in Sussex it could turn many signals along the East Coast Main Line dark.  A national artery would grind to a halt and train services as far away as Aberdeen and Penzance could be impacted.  A defective pull on Liskeard Down Home will delay nothing by more than a few minutes because the half-hourly train can be flagged past.  And one which happened to me very recently - spotting a trespasser on the line I made an emergency call to the relevant signaller who took the call in Basingstoke but with the words "Signaller Fel ... no .... Strawberry Hill"  Because he was assigned the Strawberry Hill workstation in the ROC which had just taken over from Feltham PSB.  By the time I had described the location and why I needed the traction current discharged the trespasser was attempting to board a train stopped at signals.  Had the local (manual) box still been open the "bobby" should have been able to see the incident and while current discharge would still require a call to the electrical control room it wouldn't have needed five safety-critical minutes of location description first.  

 

Progress where it offers clear benefits is fine.  Where there is no demonstrable need then "if it ain't broken don't fix it".  Other opinions are available.  

 

Hi,

 

I can totally understand the concern about 'putting all your eggs in one basket'. However, the reality is that events such as the one you describe about Three Bridges are very very rare, in fact, I've only ever heard them described theoretically.

 

But you are right in that there is a risk that such a problem can occur, but stuff has been done to minimise that risk. The data links to each interlocking are not shared across the same cable, are duplicated for availability and are diversely routed so that one cable being cut won't take down the whole centre. Really the only problems that would knock out a centre is a fire or power cut, but both of those problems are guarded against quite extensively. 

 

Such large control centres have been around in the UK for many years and for much longer around the world, so given their longevity and the amount they control, if there were serious problems with the concept, we would have changed it by now.

 

In terms of local knowledge being lost in Cornwall, I don't think that'll be the case, Exeter has chosen to allow the existing signallers and operations staff to move over much more easily and so that the local knowledge is not lost, I certainly haven't heard of any concerns (and the ops are more than willing to tell us when we get it wrong!). The signalling industry has been working really hard to learn from the incidents that have happened through 'local knowledge' problems, so that it is minimised.

 

The fact is that the signalling in Cornwall needed changing, so why not put in a modern system that provides more capacity (both now and in the future) and put into a place that allows for further growth in the future? There are lots of benefits in using a computer-based interlocking and VDU workstation over a mechanical locking:

 

  • Safer – The safe of the regular operation of a Mechanical Locking, does rely on a SIL0 element (the signaller) for some operations, where as a computer based interlocking relies only on a SIL2 system (the workstation) and SIL4 system (the interlocking) for its regular day to day operation.  Don’t get me wrong, Mechanical Signalling is not unsafe at all, but a CBI (and RRI) is safer, so we should take opportunity to upgrade where it is reasonable opportunity
  • Capacity – CBIs have far more capacity for future alterations than any Mechanical Locking.
  • Integrates with Passenger Information Systems – A workstation can provide a real time direct feed to both station and web-based information systems. A Mechanical box just can’t.
  • Integration of Train Describer and route setting – An ARS subsystem can be provided on the workstation so that the chances of misrouting a train is far less likely (okay, Cornwall is a two track railway which few places to go wrong, but ARS allows the signaller to concentrate on problems without having to worry about setting and cancelling routes).
  • Automatic Recording of signaller actions and interlocking commands – This may be seen as ‘big brother’, but is crucial for review of and learning from incidents and actions
  • Greater Situational Awareness for the Signaller – A workstation can be configured to give the signaller warnings of SPADs, irregular track section occupation etc so the signaller knows more of what is going on more of the time
  • Staff Safety System Integration – TAWS and Lockouts can be more easily provided with a workstation (or panel).

 

Colour light signals, particularly the fold down LED type, means that there’s no need to have people working at height, and that there is less to go wrong, Axle Counters provide a more robust train detection method.

 

Simon

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1 hour ago, St. Simon said:

Axle Counters provide a more robust train detection method.

More robust than what?  So far most of the failures arising from migration of the area I am most familiar with into Basingstoke ROC have been axle-counter issues. The only network-wide ones have been cable issues.  

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1 hour ago, Gwiwer said:

More robust than what?  So far most of the failures arising from migration of the area I am most familiar with into Basingstoke ROC have been axle-counter issues. The only network-wide ones have been cable issues.  


Hi,

 

Sorry, I meant more robust than Track Circuits in terms of safety.

 

Axle Counters will detect any metal object except for small hand tools, so will always detect a train. A Track Circuit relies on the axles of a train not only making contact with the rails, but also having a lower electrical resistance than the track relay, which is not always the case (albeit a small proportion of cases). Yes, Axle Counter won’t detect an RRV being placed on the tracks in the middle of a section, but it’s not guaranteed that it would be detected by a Track Circuit.
 

The clearance of an Axle Counter section works using the concept of ‘and’ logic, I.e. a train has been counted in AND a train has been counted out or that the signaller has reset the section AND a sweep train has visually proved it clear. 

 

Where as a Track Circuit just clears, which doesn’t necessarily prove the train has left the section, it might have derailed or hit a rusty patch for instance. Now, the vast majority of the time a Track Circuit clearing does prove the section is safe to proceed through, so it is a completely valid method of train detection, but a TC showing clear when occupied is not an rare occurrence by any means.

 

I will agree that Axle Counters tend to throw more wobblers initially but they do settle down, Frauscher A/Cs seem to be very reliable.


Of course, Axle Counters aren’t affected by water, leaf fall, poor ballast conditions, failed IRJs, Ice where as Track Circuits are.

 

Simon

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10 hours ago, St. Simon said:

The fact is that the signalling in Cornwall needed changing

That's probably what raises doubt in most people's minds.

 

10 hours ago, St. Simon said:

Axle Counters provide a more robust train detection method.

Probably so but as a bit of an old-fashioned rolling stock engineer I still have concerns around broken rails.

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15 hours ago, St Enodoc said:

Probably so but as a bit of an old-fashioned rolling stock engineer I still have concerns around broken rails.

 

Hi,

 

This is a long held argument, but Track Circuits were never designed for detecting rail breaks and they aren't used for detecting broken rail, actually they are very poor at detecting broken rails, I would say broken rails are more often detected by other means (patrolling / trains) than the Track Circuits showing occupied.

 

You need a clean break through the whole rail by a few mm and on a dry day for it drop the Track Circuit.

 

Rail break detection is just a happy coincidence for a Track Circuit, but it does not form any part of the safety case or mitigations for running trains, so changing to axle counters should not be cause for concern.

 

Simon 

 

 

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5 minutes ago, St. Simon said:

 

Hi,

 

This is a long held argument, but Track Circuits were never designed for detecting rail breaks and they aren't used for detecting broken rail, actually they are very poor at detecting broken rails, I would say broken rails are more often detected by other means (patrolling / trains) than the Track Circuits showing occupied.

 

You need a clean rail through the whole rail by a few mm and on a dry day for it drop the Track Circuit.

 

Rail break detection is just a happy coincidence for a Track Circuit, but it does not form any part of the safety case or mitigations for running trains, so changing to axle counters should not be cause for concern.

 

Simon 

 

 

We'll have to agree to disagree, Simon.

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An exchange of opinion between two “Cornish saints” is not something I expected to witness in 2021 :jester:

 

https://en.m.wikipedia.org/wiki/Jack_the_Giant_Killer

 

I remain of the opinion that Cornwall is well served by its existing signalling (wear and tear allowed for of course) and that the money could be better spent elsewhere. 
 

 

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2 hours ago, Gwiwer said:

An exchange of opinion between two “Cornish saints” is not something I expected to witness in 2021 :jester:

 

https://en.m.wikipedia.org/wiki/Jack_the_Giant_Killer

 

I remain of the opinion that Cornwall is well served by its existing signalling (wear and tear allowed for of course) and that the money could be better spent elsewhere. 

 

Hi,

 

I wouldn't call myself a 'saint'! :lol:

 

I think there is a bit of confusion, the signalling is being changed not because it isn't performing to expectations, it is because of wear and tear (I can't say anymore than that). If that wasn't the case, yes, I would say keep it as it is.

 

Simon

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Progress in signaling is obviously a good thing as semaphores have reached a noble old age.  Those that are sorry to see them go are mostly railway enthusiasts, while nobody else cares or even knows of.  So let them go and be glad that a few will still be around for while yet.  This same scenario is played out whenever it may happen on the railway, be it signals, stations or signal boxes.  We all are fortunate that such relics can still be found on preserved lines.

  Brian.

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12 hours ago, brianusa said:

Those that are sorry to see them go are mostly railway enthusiasts, while nobody else cares or even knows of.

Err….that was the point :lol:

 

Eventually there will be no signals…at all….and no drivers….mind you there my not be any passengers by then as well!  We’ll all be bubbling along in silent plastic bubbles from door to door while we sleep/doze/read or just contemplate whatever happened to the “good old days” ;)

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And seen approaching Par just after 4pm passing one of the semaphores now living on borrowed time (just visible - dismantling already commenced, one of its finials is missing!)WP_20210703_16_04_24_Pro.jpg.23e05f81cbee73394cb1795f7980c14c.jpg

I wonder how many people realise that the lead loco here is the former XP64 D1733, still going strong.....? (The other one started life as Scottish-allocated D1973 and was the last '47' I ever copped, at Swindon around 1990 - my 509th out out 512. Just don't mention 47307, I still get upset :chok_mini:!)

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Hi

The statesman came to Cornwall again today & having just missed it last time i was determined to see it today......

 

It duly passed on it's way down to Penzance at about 12.30.

I was at the Tesco Pool bridge......

47593 leading 47853

 

IMG_2017.resized.JPG.392935c416bf3226cf1e60caaaaf286e.JPG

IMG_2018.resized.JPG.25ad5758d1b7f12822d8912882b89890.JPG

 

IMG_2020.resized.JPG.b0784af4ae85dd574abc44cf1922f4b0.JPG

 

It returned at about 3.45 & I watched it go past from Cooks Kitchen bridge....

 

First a picture of the preceding train headed by Kingswear Castle.....

 

IMG_2021.resized.JPG.9c7d0669944d481d5d706a186ac28308.JPG

 

Followed 10 mins later by the clagging 47''s ....

This time 47853 leading on the way home.....

 

IMG_2026.resized.JPG.e37a702c1cb81f474be36d83dd931a0d.JPG

 

IMG_2027.resized.JPG.ecea752cba196fa29a1f497d022e444b.JPG

 

IMG_2030.resized.JPG.f300365718ff1aac4d8e029d7cfe0b40.JPG

 

Cheers Bill

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