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Porterbrook Cl.769 'Flex' trains from 319s, initially for Northern

Roose

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Other than Windermere (where 769s can't be used long term because of not meeting the Northern Connect standard)...
Most Windermere services weren't intended to be Northern Connect, just those to Manchester Airport - four per day. Those four will need to be refurbished Class 158 or Class 195 now, according to Northern's rolling stock plan as it stands.

My (Crayola) take on this is that all the via Lancaster services to Morecambe, Leeds, Barrow and Windermere could all use 769s if they work reliably and properly. Fleet in one area which uses 319s too, all services that make use of electric traction for parts of the routes.
While it would be a neat solution from a geographic point of view, the diagrams in this area spread much further.

Class 319 units are not in use in the area.

I would wonder whether Class 769 units might be more suitable for services where a higher proportion of use is likely to be on electrified lines than the Barrow and Leeds lines?
 
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samuelmorris

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Unless you mean they shouldn't have canned a load of electrification, how do you propose those 350/2s are used to replace 150s?

FWIW the 350/2s are rather a special case. They're going off lease because of the ludicrous price and conditions of said lease (the same lease that results in them staying in on weekends and 4-car sets being run around full and standing). The other 350s which are remaining are on far better terms. I think what was done needed to be done for them to be offered to another TOC on better terms.

I don't, that's exactly the issue. New EMUs are being ordered to replace not-necessarily-life-expired EMUs while most-definitely-life-expired DMUs are still being worked intensively with no sign of replacement in the near future.

If the lease conditions are untenable then that's the sort of thing that ought to be renegotiated rather than leave the investment sitting unused.
 

Bletchleyite

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I would wonder whether Class 769 units might be more suitable for services where a higher proportion of use is likely to be on electrified lines than the Barrow and Leeds lines?

Erm, Manchester Airport to Barrow is a textbook use for these units. 100mph under the wires for the bulk of the journey (so no 75mph DMUs getting in the way on the WCML), a much lower speed on diesel for the last bit.

I still wish Northern had ordered some FLIRT bi-mode sets for these service groups.
 

Bletchleyite

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If the lease conditions are untenable then that's the sort of thing that ought to be renegotiated rather than leave the investment sitting unused.

And if the ROSCO refuses? You can't make them, your final resolution can only be to withdraw your custom, as Abellio did. Had the rate been reasonable, I'm sure they'd have stayed (and possibly been refurbed to 2+2 seating and 110mph, the latter is still happening as they'll be around for a bit).
 

AndrewE

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Erm, Manchester Airport to Barrow is a textbook use for these units. 100mph under the wires for the bulk of the journey (so no 75mph DMUs getting in the way on the WCML), a much lower speed on diesel for the last bit.
Agree about under the wires for the bulk, but how much will be 100mph? I would guess just the 27 miles Preston to Carnforth!
 

43096

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other than possibly the 458s which are very early post privatisation EMUs and aren't even that good (like the similarly mediocre Classes 175/180).
Errrrrrr. Have you ever actually been one of those units?

I'm currently sat on a 458 and I'd say they are just about the best suburban units we have. Certainly superior to a 450 and vastly superior to a 707. The only real issue is the toilets - which could be fixed if they had a longer life remaining.
 

Mathew S

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Good point - but if they run via Bolton it's only an extra 5 1/2 miles from Euxton Junction.
This is true, but they have to run via Golborne to meet the franchise requirement of a <=30 minute service between Wigan and Manchester. TPE aren't allowed to run that service from TSR2 onwards, so it's Northern or nothing, and that means the Cumbrian trains.
 

northwichcat

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Most Windermere services weren't intended to be Northern Connect, just those to Manchester Airport - four per day. Those four will need to be refurbished Class 158 or Class 195 now, according to Northern's rolling stock plan as it stands.

The intention was for a standard pattern hourly Northern Connect service from Manchester Airport to Lancaster with most services continuing to Barrow but 4tpd continuing to Windermere. Like I said in a later post DfT said Windermere will get 195s in the announcement where it was confirmed electrification has been cancelled.
 

northwichcat

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This is true, but they have to run via Golborne to meet the franchise requirement of a <=30 minute service between Wigan and Manchester. TPE aren't allowed to run that service from TSR2 onwards, so it's Northern or nothing, and that means the Cumbrian trains.

If there's no wires usable wires between Manchester and Preston via Bolton then TPE can't run Scottish services that way from May as the only stock they have available for them is 350/4s which can't run off the wires.
 

47802

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While using them as Bi-mode may be preferable, Porterbook seem to be suggesting that running costs will be on a par or better than a Pair of 150's on Diesel, so you don't necessarily have to run them on Bi-mode routes, indeed I don't see the Welsh ones being used in Bi-mode much. On the face of it running them from Manchester to Barrow and Windermere may seem like a good idea, but as has been said time and time again they don't meet the quality standard required in 2019.

While they may get more orders than they presently I still don't see big demand for these trains and any franchise coming up for renewal requiring regional DMU's I think will continue the trend of new DMU's or Bi-modes
 
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Bevan Price

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Also, if the graph is authentic, is it for both types empty full or even crush loaded and what was the fuel load of the sprinter? The heavier the passenger/fuel load load, the more the sprinter would suffer. If the curve is representative and repeatable, the difference would only affect timetabling where there were several short runs meaning that trains needed to slow down before reaching 40mph, - even then it would only make about 5 seconds difference per stop.

The graph was measured by me, using GPS, taking speed measurements every 5 seconds. The trains were starting eastbound from Wavetree Technology Park, and were perhaps around 20% full. As a passenger, I have no access to fuel load, etc. Several repeats have been performed here, at other locations and with other classes. Whilst not all runs were identical, the trends in the graph were typical of day to day performance. Classes 150 & 142 were similar (but not identical) to Class 156.

(The GPS unit may have a short delay in response time, but that will apply equally to all classes of train.; unfortunately, lack of GPS signal inside the train prevents measurements in Classes 220, 221 & 222. Class 185 has the fastest acceleration of any dmu measured to date. Somewhat to my surprise, Classes 323 & 350 gave almost identical low speed acceleration curves - both a lot better than Class 319.)
 

Mathew S

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fulmar

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Most Windermere services weren't intended to be Northern Connect, just those to Manchester Airport - four per day.

The normal branch service can't really be separated from the through Manchester trains. Typically a train from Manchester will run through to Windermere, do two or three return trips on the branch, then form a through service back to Manchester.

That said, I don't think the 769s will be ready for May either, so I can see it happening at the same time.

The 769s seem to have run into some technical problems, which I am told is the reason for class 158 training starting imminently for drivers on the Cumbrian services.
 

AM9

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The graph was measured by me, using GPS, taking speed measurements every 5 seconds. The trains were starting eastbound from Wavetree Technology Park, and were perhaps around 20% full. As a passenger, I have no access to fuel load, etc. Several repeats have been performed here, at other locations and with other classes. Whilst not all runs were identical, the trends in the graph were typical of day to day performance. Classes 150 & 142 were similar (but not identical) to Class 156.

(The GPS unit may have a short delay in response time, but that will apply equally to all classes of train.; unfortunately, lack of GPS signal inside the train prevents measurements in Classes 220, 221 & 222. Class 185 has the fastest acceleration of any dmu measured to date. Somewhat to my surprise, Classes 323 & 350 gave almost identical low speed acceleration curves - both a lot better than Class 319.)

It seems that RoSCos are reluctant to make figures for the acceleration performance of their stocks easily available. So, assuming your curves are representative, and that the braking performance of all passenger stock is equitable *, the likely difference under service conditions on worst-case runs between stations well under 1 mile apart is about 5 seconds and certainly no more than 10 seconds. On 319/769 runs greater than that, those few seconds lost by poor low-speed acceleration would rapidly be made up by the superior acceleration above 35mph. Even on branch lines, there can't be many long stretches of 30mph PSRs. I can think of a couple of gaps on open mainline of about 1 mile, Roby/Huyton and Kearsley/Farnworth/Moses Gate. There was much talk here about the 319s struggling with the Chat Moss route whilst it was being electrified which when it happened proved to have no adverse impact on the service. When the Manchester-Bolton OLE goes live, I doubt whether the 319s will have any problems there either.
* In the case of a 769 under OLE, braking would be mostly rheostatic, cleaner and much less of an impact on maintenance intervals than friction braking only.
 

gazthomas

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The normal branch service can't really be separated from the through Manchester trains. Typically a train from Manchester will run through to Windermere, do two or three return trips on the branch, then form a through service back to Manchester.

The 769s seem to have run into some technical problems, which I am told is the reason for class 158 training starting imminently for drivers on the Cumbrian services.
I knew they would be late - it is a British disease these days :(
 

Mathew S

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The 769s seem to have run into some technical problems, which I am told is the reason for class 158 training starting imminently for drivers on the Cumbrian services.
That's the least surprising thing I've read all day, sadly. Is the 158 training using the units that have come down from Scotrail?
 

D365

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It seems that RoSCos are reluctant to make figures for the acceleration performance of their stocks easily available...

It’s generally not the ROSCOs that are responsible for performance data, I am aware of the general format in which said data is released but can’t say whether it is available within the public domain.

* In the case of a 769 under OLE, braking would be mostly rheostatic, cleaner and much less of an impact on maintenance intervals than friction braking only.

Why would rheostatic not be possible under diesel? It’s kinetic to electrical to hear energy, through use of onboard resistor banks.
 

edwin_m

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It seems that RoSCos are reluctant to make figures for the acceleration performance of their stocks easily available. So, assuming your curves are representative, and that the braking performance of all passenger stock is equitable *, the likely difference under service conditions on worst-case runs between stations well under 1 mile apart is about 5 seconds and certainly no more than 10 seconds. On 319/769 runs greater than that, those few seconds lost by poor low-speed acceleration would rapidly be made up by the superior acceleration above 35mph. Even on branch lines, there can't be many long stretches of 30mph PSRs. I can think of a couple of gaps on open mainline of about 1 mile, Roby/Huyton and Kearsley/Farnworth/Moses Gate. There was much talk here about the 319s struggling with the Chat Moss route whilst it was being electrified which when it happened proved to have no adverse impact on the service. When the Manchester-Bolton OLE goes live, I doubt whether the 319s will have any problems there either.
* In the case of a 769 under OLE, braking would be mostly rheostatic, cleaner and much less of an impact on maintenance intervals than friction braking only.

Also need to bear in mind the effect of gradient. Each 1% of adverse gradient knocks 1% of gravity off the acceleration (roundly 0.1m/s2, more than 10% of the maximum acceleration available to this sort of train), so increases the time the 769 spends in the low-speed zone where it is out-performed by a 150. While it will also accelerate more rapidly downhill, all trains benefit equally from this assuming similar braking and driver behaviour. The Chat Moss is totally flat so what happens there may not be repeated on, say, the Buxton line.

Also it's not 30mph PSRs that make a difference, its repeated PSRs or station stops each imposing its own acceleration back to normal speed. Trains with fewer wheels powered will also be more likely to suffer from wheelspin when adhesion is poor - disc and rheostatic brakes on a 769 versus tread brakes on a 150 could also be a concern for the more leafy routes. I assume that as the 769 is effectively an electric train that doesn't know it's being powered by a diesel, it will use rheostatic equally in either mode.
 
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AM9

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It’s generally not the ROSCOs that are responsible for performance data, I am aware of the general format in which said data is released but can’t say whether it is available within the public domain.



Why would rheostatic not be possible under diesel? It’s kinetic to electrical to hear energy, through use of onboard resistor banks.

I said it in the context of Sprinters and Pacers. DMUs don't have electric motors to load up for braking. Yes you are right that DEMUs as the 769s would effectively be could be made to dump power in the resistors for braking, as Voyagers and Meridians do.
 

AM9

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Also need to bear in mind the effect of gradient. Each 1% of adverse gradient knocks 1% of gravity off the acceleration (roundly 0.1m/s2, more than 10% of the maximum acceleration available to this sort of train), so increases the time the 769 spends in the low-speed zone where it is out-performed by a 150. While it will also accelerate more rapidly downhill, all trains benefit equally from this assuming similar braking and driver behaviour. The Chat Moss is totally flat so what happens there may not be repeated on, say, the Buxton line.

Also it's not 30mph PSRs that make a difference, its repeated PSRs or station stops each imposing its own acceleration back to normal speed. Trains with fewer wheels powered will also be more likely to suffer from wheelspin when adhesion is poor - disc and rheostatic brakes on a 769 versus tread brakes on a 150 could also be a concern for the more leafy routes. I assume that as the 769 is effectively an electric train that doesn't know it's being powered by a diesel, it will use rheostatic equally in either mode.

The gradients wouls work slightly against the 769s when not under OLE, but their recovery on normal electrified lines would cancel that out. Their performance on MML and TL core lines was satisfactory despite starting gradients of up to 1:29 and long hauls up to the Elstree tunnels with a very intensive service.
 

D365

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I said it in the context of Sprinters and Pacers. DMUs don't have electric motors to load up for braking. Yes you are right that DEMUs as the 769s would effectively be could be made to dump power in the resistors for braking, as Voyagers and Meridians do.

Ah right, the way your post was written suggested that the 769s wouldn’t have rheostatic braking off the wires.
 

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