GWML Electification

[Edwin_m]

11 hours ago, rodent279 said:

Aye, I know the the word "miniature" was used in a relative sense! I have seen the real thing a couple of times. To me, miniature is anything under a cm or so!

I guess they are built for reliability, robustness and longevity in service, rather than space saving.

And in particular safety.  The safety of relay interlockings relies on any fault causing the relays in question to de-energise, which puts the signal to red or sets whatever else it controls to the most restrictive state.  So the relay must be designed to avoid faults such as welded contacts which could cause a "wrong side" failure.  

[jamie92208]

1 hour ago, Edwin_m said:

And in particular safety.  The safety of relay interlockings relies on any fault causing the relays in question to de-energise, which puts the signal to red or sets whatever else it controls to the most restrictive state.  So the relay must be designed to avoid faults such as welded contacts which could cause a "wrong side" failure.  

ISTR being told that they were always installed in the same orientation so that gravity caused them to fail safe.

 

Jamie

[caradoc]

Very early in the days of Railtrack an issue affecting relays at Edinburgh SC was identified, 'silver migration'. It was concerning enough that multiple routes in the Haymarket area were taken out of use, meaning for example trains from the Midcalder Jc direction had to use the Suburban Line to access Edinburgh.

 

[iands]

I first came across 'silver migration' in the 70s when I was at Selby. From memory the problem was identified as a problem with the BR930 series plug-in relay bases - something to do with the material/compound make-up used in the bases made them quite prone to the problem. I remember having to take extra notice on maintenance visits to relay rooms/lineside locs and closely examining the relay bases for the tell-tale signs of silver migration. Resulted in an extensive programme, with quite a few Sundays, changing out 'black' bases for 'blue' ones. 

[Dava]

Waiting for a train at Cardiff Central, none of the Hitachi trains I saw on London services had pans up & all were running on diesel. What was the point of the colossally expensive electrification through Severn Tunnel and along South Wales Mainline if it’s not used? No electric freight or commuter services either. Yet the cost overruns we’re why Grayling cancelled Midland Mainline electrification. Now we’ve lost HS2 East as well apparently.

 

If DfT is going to electrify it must require usage. NetZero 2030 anyone?

 

Dava

[KeithHC]

4 minutes ago, Dava said:

Waiting for a train at Cardiff Central, none of the Hitachi trains I saw on London services had pans up & all were running on diesel. What was the point of the colossally expensive electrification through Severn Tunnel and along South Wales Mainline if it’s not used? No electric freight or commuter services either. Yet the cost overruns we’re why Grayling cancelled Midland Mainline electrification. Now we’ve lost HS2 East as well apparently.

 

If DfT is going to electrify it must require usage. NetZero 2030 anyone?

 

Dava

Could it be due to the flooding in the Severn Tunnel.

 

Keith

[Mike_Walker]

There may be a temporary problem with the OLE in South Wales in which case it shows one advantage of bi-modes!  As Keith says above there has been flooding in the Severn Tunnel.

 

However, there is a permanent situation at Cardiff where terminating trains which have come from London on electric power have to switch to diesel to make the shunt across the station either by reversing on Line A opposite Canton depot or in Brickyard Siding despite being under live OLE at all times.  You can blame the ORR for this.  They think the risk of a train setting off for Swansea with its pan up to be too great and insisted that beacons be installed at the west end of Cardiff station to instruct any 80x train passing it to lower its pan if raised.  Luckily for GWR and common sense, the 387s don't respond to these so they can make the shunt on electric power but it took a lot of persuading before the ORR would agree to it.  For some reason the folk at the ORR (who have probably little or no railway operating experience - I know one who was previously a lawyer) seem to think that drivers and signallers are idiots who cannot be trusted to do their jobs rather than the dedicated professionals they actually are.

[St. Simon]

3 hours ago, Mike_Walker said:

However, there is a permanent situation at Cardiff where terminating trains which have come from London on electric power have to switch to diesel to make the shunt across the station either by reversing on Line A opposite Canton depot or in Brickyard Siding despite being under live OLE at all times.  You can blame the ORR for this.  They think the risk of a train setting off for Swansea with its pan up to be too great and insisted that beacons be installed at the west end of Cardiff station to instruct any 80x train passing it to lower its pan if raised.  Luckily for GWR and common sense, the 387s don't respond to these so they can make the shunt on electric power but it took a lot of persuading before the ORR would agree to it.  For some reason the folk at the ORR (who have probably little or no railway operating experience - I know one who was previously a lawyer) seem to think that drivers and signallers are idiots who cannot be trusted to do their jobs rather than the dedicated professionals they actually are.

 

Hi,

 

Lot of that is false, it wasn't the DFT that insisted that Balises (not Beacons) were installed at Cardiff Central, it was a joint decision between Great Western and Network Rail. 

 

Line A is not wired for turnback moves, only Brickyard Sidings are wired. the ideal situation would be to allow Class 80x units to turnback in Electric in Brickyard Sidings, however, the reason for not doing it was that we (trained and licensed Signaller Designers) couldn't protect the end of the OLE without putting the Balises before the point of divergence (i.e, right at the end of the Platforms), and there is no technical way, without installing ETCS and linking the PCO information with the Movement Authority received by the train, of telling the trains TMS (the system that manages the PCO process) the route that it is actually taking (and no, you can't use the headcode changes etc). This decision wasn't anything to do with ORR, nor was the running of the 387s (other than the general authorisation for the units to enter service).

 

 The reason for providing the Automated Back Up via ETCS Packet 44 Data was NOT because of a 'lack of trust' of signallers or drivers, it is because  the risk of a significant de-wirement event, should the driver get it wrong and a pantograph still be raised when the wires ran out, was too great, and frankly, it turns out it is needed at Cardiff. There are other ends of OLE on the Great Western that don't have Balises installed as has been assessed to be low risk if the driver gets it wrong.

 

There is a fair risk of a Driver forgetting to do the change-over at Cardiff, considering that the driver has to perform station duties as well as set the train up (changing headcodes etc) for the ECS movement.

 

Simon

[Mike_Walker]

Line A is electrified as far as LOS CF7051 and Brickyard Siding branches off it. It is used regularly by the 387 training runs.  Lines B-E are wired to just beyond the signal gantry at 170m 60c.

[St. Simon]

6 minutes ago, Mike_Walker said:

Line A is electrified as far as LOS CF7051 and Brickyard Siding branches off it. It is used regularly by the 387 training runs.  Lines B-E are wired to just beyond the signal gantry at 170m 60c.

 

Hi,

 

Okay, yes you are right, I was thinking of the lines as the running the other way!

 

Simon

[St. Simon]

3 hours ago, KeithHC said:

Could it be due to the flooding in the Severn Tunnel.

 

Keith

 

Hi,

 

There is a Power Change-Over Installation at Severn Tunnel Junction that allows for trains to run electric between Severn Tunnel Junction and Cardiff should the Severn Tunnel be in 'Diesel' Mode if they so wish, not quite sure what the problem was in this case.

 

Simon

[Peter Kazmierczak]

Just wondering.
If an IET ran out of OLE with its pan up doing the shunt move to Brickyard Sdg, would it actually do any damage?

[jamie92208]

7 minutes ago, Peter Kazmierczak said:

Just wondering.
If an IET ran out of OLE with its pan up doing the shunt move to Brickyard Sdg, would it actually do any damage?

I presume  that there isn't a tunnel just beyond the station like the one at Dollands Moor that has removed a few pantographs from Eurostars. Surely the automatic pan drop mechanism would come into play.  ISTR signs sayi g "Electric Trains Stop Here' on the 1960 s schemes.

 

Jamie

[Mike_Walker]

11 minutes ago, Peter Kazmierczak said:

Just wondering.
If an IET ran out of OLE with its pan up doing the shunt move to Brickyard Sdg, would it actually do any damage?

No!

[Peter Kazmierczak]

Thanks guys. So are all the shenanigan's at the west end of Cardiff, a non-problem looking for a (over-engineered and costly) solution? 

[St. Simon]

51 minutes ago, Peter Kazmierczak said:

Just wondering.
If an IET ran out of OLE with its pan up doing the shunt move to Brickyard Sdg, would it actually do any damage?

 

Hi,

 

Not to Brickyard Sidings, no, that's not the issue.

 

The issue is that if it started off to Swansea or the Valley (? Sorry, can't remember from the scheme plan) with it's pan up then it would do very significant damage to the OLE. 

 

However, there was no technical way of ensuring that a Class 80x would lower it's pan if route towards the non-electrified lines whilst allowing an electric shunt move towards the Brickyard due to the layout OLE.

 

Simon

Edited October 30, 2021 by St. Simon

[Peter Kazmierczak]

Thanks for the clarification Simon. I have enough problems wiring a 3-pin plug... It just seems crazy to me that an electric train has to go into diesel mode to enter an electrified siding. But such is the way of things I suppose.

[St. Simon]

6 minutes ago, Peter Kazmierczak said:

Thanks for the clarification Simon. I have enough problems wiring a 3-pin plug... It just seems crazy to me that an electric train has to go into diesel mode to enter an electrified siding. But such is the way of things I suppose.

 

Hi Peter,

 

You are right, it is a bit crazy, we did try very hard and explored every avenue to get Electric 80x's down to the Brickyard!

 

Simon

[jamie92208]

Just as a hypothetical, if and when the bimodes that were converted from what should have been straight electrics, ever have their power packs removed, will they be able to use the Brickyard under electric power.

 

Jamie

[Zomboid]

Presumably so, since 387s don't need to summon a locomotive to push them in/ out.

[St. Simon]

50 minutes ago, jamie92208 said:

Just as a hypothetical, if and when the bimodes that were converted from what should have been straight electrics, ever have their power packs removed, will they be able to use the Brickyard under electric power.

 

Jamie

 

Hi Jamie,

 

Yes, the only thing would be to check that they wouldn't respond to the Packet 44 Data, which I assume they wouldn't as they can't convert to Diesel so would ignore it, but I don't have the interface spec on me

 

Simon

[jamie92208]

2 minutes ago, St. Simon said:

 

Hi Jamie,

 

Yes, the only thing would be to check that they wouldn't respond to the Packet 44 Data, which I assume they wouldn't as they can't convert to Diesel so would ignore it, but I don't have the interface spec on me

 

Simon

Thanks for that Simon. I won't hold my breath waiting for it to happen though

 

Jamie

[Edwin_m]

6 hours ago, St. Simon said:

 

there is no technical way, without installing ETCS and linking the PCO information with the Movement Authority received by the train, of telling the trains TMS (the system that manages the PCO process) the route that it is actually taking (and no, you can't use the headcode changes etc).

Couldn't an output be provided from the signalling to disable the balise when the route is set to the electrified siding?  

[Zomboid]

1 hour ago, Edwin_m said:

Couldn't an output be provided from the signalling to disable the balise when the route is set to the electrified siding?  

Clearly not. The present situation is ludicrous enough that every possible solution to avoid it will surely have been investigated, and the resulting situation is the least worst option within the fixed parameters.

 

I feel sorry for whoever had to sign off on electric trains being unable to use an electrified siding, but there it is. No viable alternatives existed.

[St. Simon]

1 hour ago, Edwin_m said:

Couldn't an output be provided from the signalling to disable the balise when the route is set to the electrified siding?  

Yes, in theory, a switchable balise is a thing, but it’s not yet a mature product in the UK (I.e. there’s still a lot of development needed to implement it and nobody has used one yet in the UK).

 

Also it would need a output TFM adding in (or at least a spare output on an existing TFM made activate), as well as altering of the Interlocking data.

 

We did debate using switchable Balises, but cost, complexity and time meant it wasn’t a viable option to realise the benefits.

 

Simon