Class 319 Flex for Wales

[phil-b259]

I can't actually see that as a problem, you can easily protect the motor-generator set from back EMF, and obviously if you're working with lowered third rail shoes then you have an existing system of interlocks you can dip into to control it all.

 

IIRC the 319s don't have moveable collector shoes - and it took quite a while before the Midland region managed to get their track staff to remember this and do things (like leave excessively high ballast shoulders) that broke them off.

 

The ones working for Northern have had their shoe gear removed so there and the Welsh ones will be the same.

 

Of course in the electro diesel concept is a success, then a few units could probably find a home on the Marshlink route, allowing the service to be extended back to Eastbourne and Brighton (Its due to be restricted to a Hastings - Ashford shuttle again to few up units for the Uckfield line in November)

[John M Upton]

I travelled on one of GWR's refurbished 158's the other day with its new spec toilet and PIS system and my first thought was what was wrong with the old toilets and PIS system?  There seems to be a lot of money being spent nationwide on fleets of DMU's and EMU's to lengthen hand rails, reverse the order of the door control buttons etc when there was nothing wrong with what was there in the first place.  The seemingly every changing specification regulations seem to be changes for changes sake.

[phil-b259]

I travelled on one of GWR's refurbished 158's the other day with its new spec toilet and PIS system and my first thought was what was wrong with the old toilets and PIS system?  There seems to be a lot of money being spent nationwide on fleets of DMU's and EMU's to lengthen hand rails, reverse the order of the door control buttons etc when there was nothing wrong with what was there in the first place.  The seemingly every changing specification regulations seem to be changes for changes sake.

 

Do you have some form of disability? If not then whether something is 'adequate' from an accessibility point if view is none of your business.

 

Its all very easy to dismiss simple things like rearranging handrails or door buttons as trivial - but to some folk less fortunate than you or I such things matter and can be the difference between whether they use the train or not. Given we generally wish to see the less able play as fuller part in society as possible then increasing awareness and legislation to enforce improvements* should be welcomed by everyone - who knows if fate deals you the wrong card in later life, you might well be thankful that someone has already made the necessary changes.

 

* Which is where the RMT / ASLEF should be focusing their attention as regards single person operation (DOO), rather than prattling on about it being inherently 'unsafe'

[Edwin_m]

The shoes on a 319 are not retractable so will be out of gauge on any non-third-rail route.  Not a problem if they are confined to a limited network, where it can be managed as the 319s were on the Midland, but it could be if they were treated as part of a common user DMU fleet over a wider network.  Hence the shoes were removed from the 319s going to Northern and as far as I know will also be removed from the Flexes even if they are theoretically still capable of DC operation. 

 

If someone ordered some for, say, Ashford-Hastings then that might be less of a problem as clearances could be checked for that short section and it's unlikely they'd find their way onto any other non-electrified routes.  I presume there's some kind of circuit breaker on 319 to prevent the shoegear being live when the AC transformer is feeding voltage into the DC train bus.  This might have to change if the existing arrangement doesn't allow the shoegear to be isolated when the diesel is powering the DC bus. 

[bingley hall]

Thanks for the link and apologies for this tangent - ........

 

 

No wonder there is apparently a growing sense of distance between "normal (sic) people" and "The Elite". Every statement feels to me like we are being treated as either dumb consumers or potentially insolent upstarts.

 

Sorry for OT rant...

 

Paul

 

That's exactly what Pol Pot used to say  

[phil-b259]

 

If someone ordered some for, say, Ashford-Hastings then that might be less of a problem as clearances could be checked for that short section and it's unlikely they'd find their way onto any other non-electrified routes.  I presume there's some kind of circuit breaker on 319 to prevent the shoegear being live when the AC transformer is feeding voltage into the DC train bus.  This might have to change if the existing arrangement doesn't allow the shoegear to be isolated when the diesel is powering the DC bus. 

 

Both the Uckfield and Marshlink lines are treated by Network Rail as though they had 3rd rail (including the use of extra strength AWS magnets, etc). Not exactly surprising as the people in charge of its maintenance now (and in previous decades), plus the kit they use is all designed with 3rd rail in mind (not mention the fact that they can only be accessed by traversing 3rd rail equipped lines)

 

And yes when on a 25KV overhead supply, the 750V DC current collecting circuits + shoegear are indeed electrically dead.

[jim.snowdon]

 

And yes when on a 25KV overhead supply, the 750V DC current collecting circuits + shoegear are indeed electrically dead.

It would have been fun at Farringdon if they hadn't been arranged that way - we could have had the train acting as a substation feeding LM electricity into the SR conductor rail.      We couldn't possibly have that.

 

Jim

[russ p]

Both the Uckfield and Marshlink lines are treated by Network Rail as though they had 3rd rail (including the use of extra strength AWS magnets, etc). Not exactly surprising as the people in charge of its maintenance now (and in previous decades), plus the kit they use is all designed with 3rd rail in mind (not mention the fact that they can only be accessed by traversing 3rd rail equipped lines)

 

And yes when on a 25KV overhead supply, the 750V DC current collecting circuits + shoegear are indeed electrically dead.

When I learned 325s 20+ years ago which are virtually the same beast I was told on 25kv the shoes were dead but the schematics we were issued with didn't seem to confirm this as there was no 750v bus line breakers and as the shoe fuses were removed this could not be proved.

I've heard 319 drivers say this is not the case and when the pan is up the shoes are live

[rodent279]

No wonder there is apparently a growing sense of distance between "normal (sic) people" and "The Elite". Every statement feels to me like we are being treated as either dumb consumers or potentially insolent upstarts.

Fantastic that, Paul! 

 

Apparently growing...?

Edited July 18, 2017 by rodent279

[rodent279]

When I learned 325s 20+ years ago which are virtually the same beast I was told on 25kv the shoes were dead but the schematics we were issued with didn't seem to confirm this as there was no 750v bus line breakers and as the shoe fuses were removed this could not be proved.

I've heard 319 drivers say this is not the case and when the pan is up the shoes are live

 

319's are chopper control, aren't they?

[Edwin_m]

319's are chopper control, aren't they?

Yes, but it isn't relevant.  The choppers are fed with DC which either comes from the shoegear or from the transformer and rectifier, just as the camshaft is on a 313.  On a 769 there is the alternative (or possibly additional) source from the diesel.

[rodent279]

Would seem a bit strange not to have some way of isolating the shoe gear when not in use.

[Zomboid]

A DCCB would be something to maintain and go wrong in the platform at Farringdon, and therefore a liability, whilst the benefits would be that the shoes would be dead whilst the pan was up. No one should be anywhere near the shoes in normal operation (other than the driver, who would have to deal with the 3rd rail anyway), and pan down whilst parked seems to be normal for EMUs.

On that basis at least I can see why no DCCB would be provided.

Edited July 19, 2017 by Zomboid

[ColinK]

Can anyone explain where these really could be used in Wales? I can't see them being used on Wrexham - Bidston - (Liverpool) as it would be a huge distance on diesel power, so that leaves a route mainly 25kv with a short section on diesel.

[black and decker boy]

Can anyone explain where these really could be used in Wales? I can't see them being used on Wrexham - Bidston - (Liverpool) as it would be a huge distance on diesel power, so that leaves a route mainly 25kv with a short section on diesel.

I think they are being suggested as a pure DMU. The fact they have 25kv capability isn't the key point in the short term.

['CHARD]

Can anyone explain where these really could be used in Wales? I can't see them being used on Wrexham - Bidston - (Liverpool) as it would be a huge distance on diesel power, so that leaves a route mainly 25kv with a short section on diesel.

 

They are in truth being offered as DMU substitutes to potter around the south Walean shorter distance rural routes while 150/2s receive toilet mods.  The 25kV is a distraction, as wiring around Cardiff is not visible in the medium term, with the exception of the LRT plan for the Valleys.

[Zomboid]

If using the 25kV is important then they could run the Manchester to Holyhead trains, Manchester to Warrington being electrified.

[phil-b259]

It would have been fun at Farringdon if they hadn't been arranged that way - we could have had the train acting as a substation feeding LM electricity into the SR conductor rail.      We couldn't possibly have that.

 

Jim

 

Good point - I hadn't considered the changeover aspect and was thinking more about when the train was moving.

 

When I learned 325s 20+ years ago which are virtually the same beast I was told on 25kv the shoes were dead but the schematics we were issued with didn't seem to confirm this as there was no 750v bus line breakers and as the shoe fuses were removed this could not be proved.

I've heard 319 drivers say this is not the case and when the pan is up the shoes are live

 

As I believe that as the 319s cannot do 'on the move' changeovers and must be static between changing modes then that does suggest a definitive 'off' stage in the process when all traction systems would be dead (unless actually being in contact with a power supply at the time.

[Christopher125]

The new Chester-Liverpool Lime Street 'Halton Curve' services would seem an obvious destination, if not for these then a second batch - not only is a significant proportion wired, but they could be maintained alongside other 319s at Allerton.
 
As for a tri-mode 'flex', Porterbrook's Helen Simpson (whose behind this project) said it was an option in a RAIL interview:

 

"we are effectively tricking the traction system into thinking it is still a DC unit. It is effectively replacing the DC operation with diesel, but we could still retain the shoegear and have a tri-mode '319' if it was needed"

Edited July 19, 2017 by Christopher125

[Titan]

Good point - I hadn't considered the changeover aspect and was thinking more about when the train was moving.

 

 

As I believe that as the 319s cannot do 'on the move' changeovers and must be static between changing modes then that does suggest a definitive 'off' stage in the process when all traction systems would be dead (unless actually being in contact with a power supply at the time.

 

I have seen them do 'on the move' changeovers, although I suspect it was not normal practice. On one occasion the driver pressed the 'pan up' button too soon and the rear pan of the train was lifting as it came out of the tunnel in to Farringdon! I swear it hit the contact wire about two feet after it began, on a bit that is not designed to have pans running on it... This was of course in the days before the remodeling. By the time it stopped at the platform it was already configured and running off the OLE.

[rodent279]

A DCCB would be something to maintain and go wrong in the platform at Farringdon, and therefore a liability, whilst the benefits would be that the shoes would be dead whilst the pan was up. No one should be anywhere near the shoes in normal operation (other than the driver, who would have to deal with the 3rd rail anyway), and pan down whilst parked seems to be normal for EMUs.

On that basis at least I can see why no DCCB would be provided.

I would have thought the risk of a D.C. circuit breaker failing in Farringdon, causing the train to be stranded, is minimal, and acceptable, compared to the risk (and consequences) of track or train staff accidentally coming into contact with an unprotected shoegear, live at or near 750v.

Plus of course, as above, when in the platform at Farringdon, the dc output from the transformer/rectifier would be in parallel with the third rail, which sounds like a smoke-generating event to me!

Edited July 19, 2017 by rodent279

[Zomboid]

I would have thought the risk of a D.C. circuit breaker failing in Farringdon, causing the train to be stranded, is minimal, and acceptable, compared to the risk (and consequences) of track or train staff accidentally coming into contact with an unprotected shoegear, live at or near 750v.

 

Maybe in 2017, but maybe not in 1988. To be honest I don't know, but I can see why a decision either way would have been made

Plus of course, as above, when in the platform at Farringdon, the dc output from the transformer/rectifier would be in parallel with the third rail, which sounds like a smoke-generating event to me!

I don't see that. It's just a rectifier fed from a single phase 25kV supply, rather than a 3 phase 11/33kV supply - and those are run in parallel all the time, everywhere.

[rodent279]

But those 3ph ac supply networks are designed to be run in parallel. A 319 isn't designed to act as an alternative supply of juice to the 3rd rail.

What if there's an earth fault on the dc with a train in section with pan up on the OHL? If there's no breaker between shoe gear and rectifier output / chopper i/p, a massive current flows from the OHL via the transformer/rectifier into the 3rd rail.

[Zomboid]

(I should start by reiterating that I don't know if there is a DCCB on a 319. I'm just going to respond assuming that there isn't)

The DC is parallelled whilst the 3ph

isn't. The rectifiers provide the segregation.

I don't know how the kit on a 319 is set up, but presumably any detected fault on the DC side of its on board rectifier would cause the AC breaker to trip (certainly anything that would constitute "massive currents" would, it's also not beyond the realms of possibility that the 25kV sub would be tripped, depending on the impedance of the train) - it's not likely that it'll be able to discriminate between the train or con rail. The substation circuit breakers can be set to handle a train regenerating, which is essentially the situation you've described.

[corneliuslundie]

It makes sense that the units are to allow refurbishment of the class 150s. It makes no sense to refurbish the Pacers as even now there is not sufficient capacity and this would reduce the number of passengers per train. In addition, they are OLD (not OLE!) and it makes no sense to spend a lot of money on them. So whatever the politicians' views on removal of the Pacers may be, they are likely to go by 2020 because it is simply not worth making them DDA compliant.

And anyway five units is only going to allow about half a dozen class 150 units at a time to be released for refurbishment. There will be no change to service patterns anywhere on ATW as a result of the arrival of these units unless there has to be deceleration to allow for lower acceleration of the hybrid units (if that is the case).

But none of this solves the long term problem. The Welsh Assembly has great aspirations but no money to fund it. There is no manpower available for any Valleys electrification scheme whether conventional or light rail, and it will not be available for some time even if MML is cancelled. So the future for rail in the Principality over the next decade is pretty dire, I am afraid.

And for the Cambrian system I can see a continuation with the existing fleet of 158s for the foreseeable future, possibly supplemented by a few more as it is known how to fit the signalling system to this design. But ERTMS has never been fitted to the other ATW classes, and retrofit is reckoned to be fraught with problems. This means that any cascaded DMUs will end up either on the existing North-South Wales route or in the Valleys.  It has been stated previously that some classes have not been cleared for the Valleys lines above Pontypridd, and any newer designs would also have to be cleared - not impossible but necessary and costing money.

Thus unless one of the bidders for the new franchise has a magic wand or a bottomless purse - and even if it wants to buy new stock it will be at the end of a very long queue at all the potential suppliers (except perhaps the Chinese).

Jonathan

Of course the hybrid units could be used on a re-opened line between Carmarthen and Aberystwyth! If £300,000 can be found by the Welsh Assembly to fund a "feasibility study" then anything is on the cards.