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

[edwin_m]

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.

That depends on the number of gradients and proportion of electrified track on a particular route, and also on the permitted speeds on those sections and elsewhere. There's also a risk of unreliability if a particular route has very severe gradients and/or autumn adhesion issues. So really it's a case by caes basis rather than saying 769s would be better or worse everywhere.

 

[Roose]

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.

This may true but only eight out of the Furness Line daily services will travel that far and creating a sub-fleet of Class 769 to meet the Northern Connect quality standard on the Furness and Lakes Lines NC services seems unlikely.

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.

That is the case, but the order for Class 195 did not take the Windermere services into account; there maybe an availability shortfall unless somewhere misses out or the alternative is used somewhere.

 

[47802]

I knew they would be late - it is a British disease these days

This may true but only eight out of the Furness Line daily services will travel that far and creating a sub-fleet of Class 769 to meet the Northern Connect quality standard on the Furness and Lakes Lines NC services seems unlikely.

That is the case, but the order for Class 195 did not take the Windermere services into account; there maybe an availability shortfall unless somewhere misses out or the alternative is used somewhere.

Are not the original 8 x 769's meant to be a cover for cancelled and defered electrification in the grand scheme of things, which probably means in practice that in lieu of 195's needed for Windermere, a few other connect services that might have got 195's originally might get 158's instead and some other non connect services which might have got 158's end up with 150's etc.

 

[Bletchleyite]

Are not the 769's meant to be a cover for cancelled and defered electrification in the grand scheme of things, which probably means in practice that in lieu of 195's needed for Windermere, a few other connect services that might have got 195's originally might get 158's instead and some other non connect services which might have got 158's end up with 150's etc.

But then something has to substitute for those 150s. There are no spare DMUs.

 

[47802]

But then something has to substitute for those 150s. There are no spare DMUs.

#
But thats what the 769's are there for to potentially cascade 150's and to have enough off wires capacity, but that doesnt mean they have to be direct replacements for Windermere or Bolton-Wigan if stock is shuffled around as required.

 

[LNW-GW Joint]

#
But thats what the 769's are there for to potentially cascade 150's and to have enough off wires capacity, but that doesnt mean they have to be direct replacements for Windermere or Bolton-Wigan if stock is shuffled around as required.

In a perfect world, wouldn't 331s have gone to Windermere (eventually)?
And they could still run to Oxenholme if they put a DMU on the branch.
I haven't really followed whether 331s can be Connect services or not, seems a bit esoteric against the stock mix you get today.

 

[47802]

In a perfect world, wouldn't 331s have gone to Windermere (eventually)?
And they could still run to Oxenholme if they put a DMU on the branch.
I haven't really followed whether 331s can be Connect services or not, seems a bit esoteric against the stock mix you get today.

331's will work both Connect and Non Connect Services, and originally these would have worked to Windermere yes, and yes they could work to Oxenholme but that wouldn't meet the franchise requirement of a minimum of 4 through trains a day to Windermere from Manchester Airport.

I don't really see why this forum is trying to make a big issue out of it, 195's can work the service until the alternate fuel train arrives, and I'm sure Arriva and the DFT in there revised calculations of cancelled and deferred electrification and procurement of the 769's have allowed for enough diesel capacity overall.

 

[Bevan Price]

Thought some of you might like to see my measured acceleration curves for Class 319 compared with Claases 323 & 350.

 

[hwl]

Thought some of you might like to see my measured acceleration curves for Class 319 compared with Claases 323 & 350.
View attachment 41673

The 319 curve looks very odd with little acceleration between 10-15mph and is possibly anomalous - is this based on only single measured run?

 

[Elecman]

The Franchise agreement regarding the Windermere Connect service specification could always be amended ( postponed until the new ‘magic’ power source trains arrive) thus allowing the use of 769s on the route in the meantime maximising the running under the wires usage, as it’s down to DfT / Grayling that Windermere isn’t getting electrified now. A real shame as Lostock Jct to Wigan and Oxenholme to Windermere would have been perfect rolling program schemes to keep the existing teams ticking over rather than being disbanded once Phase 3 (and 4 are completed whilst Manchester Leeds Phase 5+ is properly planned.

 

[47802]

The Franchise agreement regarding the Windermere Connect service specification could always be amended ( postponed until the new ‘magic’ power source trains arrive) thus allowing the use of 769s on the route in the meantime maximising the running under the wires usage, as it’s down to DfT / Grayling that Windermere isn’t getting electrified now. A real shame as Lostock Jct to Wigan and Oxenholme to Windermere would have been perfect rolling program schemes to keep the existing teams ticking over rather than being disbanded once Phase 3 (and 4 are completed whilst Manchester Leeds Phase 5+ is properly planned.

Perhaps they could alter it the service spec but it doesn't mean they will.

if you believe Porterbook running costs will be comparable if not better than running a 2x150 on Diesel, so Arriva may not be that bothered about trying to maximise under the wire usage, Leasing costs are supposed to be quite high but given the reasons for having these trains at Northern is not the TOC's fault one suspects the Dft have had to do a deal on that.

 

[Bevan Price]

The 319 curve looks very odd with little acceleration between 10-15mph and is possibly anomalous - is this based on only single measured run?

It was one of numerous typical measurements in the months after 319s started to run out of Liverpool; they were not all identical, and small anomalies are always possible in GPS speed measurements - or alternatively there may have been slight slippage. I think I have had slighter better acceleration in more recent runs, as drivers became more familiar with the type.

The comparison is not exact, because they were recorded at different locations - but in all cases the gradients were level or gentle, and there were no "low speed" restrictions at the start.

 

[samuelmorris]

Thought some of you might like to see my measured acceleration curves for Class 319 compared with Claases 323 & 350.
View attachment 41673

I'm intrigued about why these figures are so low for some of the better performing stock on the network. I measured a 345 at almost exactly 30 seconds 0-60 the other day which vastly surpasses what the 350 and 323 achieve there. I appreciate they might be slightly faster units but I'm not sure the difference should be that great. I'm sure I remember seeing the 0-60 time for the 360 (therefore I presume the 350 too?) at 45 seconds...

 

[Bevan Price]

I'm intrigued about why these figures are so low for some of the better performing stock on the network. I measured a 345 at almost exactly 30 seconds 0-60 the other day which vastly surpasses what the 350 and 323 achieve there. I appreciate they might be slightly faster units but I'm not sure the difference should be that great. I'm sure I remember seeing the 0-60 time for the 360 (therefore I presume the 350 too?) at 45 seconds...

Part of the difference might be ascribed to the design (gearing, etc.) For example, they can design trains for rapid acceleration, but sacrifice a high maximum speed capability.

 

[Domh245]

I'm intrigued about why these figures are so low for some of the better performing stock on the network. I measured a 345 at almost exactly 30 seconds 0-60 the other day which vastly surpasses what the 350 and 323 achieve there. I appreciate they might be slightly faster units but I'm not sure the difference should be that great. I'm sure I remember seeing the 0-60 time for the 360 (therefore I presume the 350 too?) at 45 seconds...

The 345 is obviously going to outperform most stock you compare it against, considering that it is designed for a 24tph metro service, and has 11.5kW/ton. For comparison, the 323 has 9.7kW/ton and the 350 8.5kW/ton

As for the question of Bevan's recorded times versus the 360's time, I would question under what conditions the 360 set it's 45 second time - full beans, downhill, on an ECS move? If nothing else, it could just be that the drivers on Bevan's recorded runs haven't been driving it flat out, but instead driving professionally and accelerating more slowly

 

[edwin_m]

Two factors that make a difference to performance are:

- Proportion of axles motored, as I think I mentioned above. Even if the power and weight are the same the acceleration will be less, particularly at low speeds, as it is limited by adhesion. A 319 only has 25% of its axles motored, it is 50% for a 350/360 and 67% for a 323.

- Use of AC rather than DC motors. An AC motor (as fitted to all EMUs from the Networkers onwards) can maintain torque and therefore acceleration much better as speed increases. This makes gearing for acceleration versus speed less important, though I believe the 345 is actually geared for 90mph rather than 100mph as well as having a lot of motored axles.

On third rail routes these benefits are partly negated by the inability of the system to supply all the power the motors could use, so the software is configured to limit performance deliberately. This is less of a problem on 25kV.

 

[Starmill]

The 319 curve looks very odd with little acceleration between 10-15mph

Have you used a 319? I think these measurements were recorded on a Northern unit? Through my uninformed eyes it very very much seems that they do accelerate very slowly in that range. However it's worth pointing out that there also seems to be a lot of variation within the fleet.

 

[AM9]

Have you used a 319? I think these measurements were recorded on a Northern unit? Through my uninformed eyes it very very much seems that they do accelerate very slowly in that range. However it's worth pointing out that there also seems to be a lot of variation within the fleet.

Speaking from having used the 319s for decades, they do vary quite a lot. Some drivers here have posted that their performance (obviously) drops off when motors are switched out when faulty, which unless there are many more than one missing, may not be as noticeable on an 8-car set. When running without a full complement of motors, I believe that it imposed restrictions on climbing the 1:29 slopes in the core. The other issue as has been hinted at is that driver experience and or technique can make a considerable difference. The 319s have 300hp motors that if in serial mode do have the torque to easily spin the wheels until the anti-slip protection kicks in. Some drivers seemed to drive them on the limit of adhesion (which would seem to affect the 10-20mph range more) whereas others seem quite cautious up to about 30-40. Such differences could account for the apparent inconsistencies in the posted curves.

 

[samuelmorris]

The 345 is obviously going to outperform most stock you compare it against, considering that it is designed for a 24tph metro service, and has 11.5kW/ton. For comparison, the 323 has 9.7kW/ton and the 350 8.5kW/ton

As for the question of Bevan's recorded times versus the 360's time, I would question under what conditions the 360 set it's 45 second time - full beans, downhill, on an ECS move? If nothing else, it could just be that the drivers on Bevan's recorded runs haven't been driving it flat out, but instead driving professionally and accelerating more slowly

This is true but both 323s and 345s are geared for 90mph and both have a similarly high proportion of powered bogies. I find it difficult to believe the difference should be that extreme. I haven't ridden 350s much I'll admit but 360s seemed very capable for acceleration 0-60, using the departure eastbound from Stratford as an example.
The 345 measurement was even uphill, taken eastbound from Harold Wood.

My thoughts are it's driving policy in the areas these studies were conducted, and if that's the case, while not to belittle the efforts of those who recorded the data, it renders the comparisons rather weak, as the driving style taught on the relevant training programmes I imagine will differ, not only per-TOC, but probably also per-stock type within the same TOC. I'm not sure real world measurements can be relied upon too much as definitive demonstration the impact of changing rolling stock will have on timekeeping etc. until the relevant units are tested on the route in question. Just look at the dubious report from GWR comparing the 'slower' HST departing at a reduced power setting versus the 'faster' 800 going flat out...

 

[hwl]

Have you used a 319? I think these measurements were recorded on a Northern unit? Through my uninformed eyes it very very much seems that they do accelerate very slowly in that range. However it's worth pointing out that there also seems to be a lot of variation within the fleet.

Yes, I've used them since 1989

Speaking from having used the 319s for decades, they do vary quite a lot. Some drivers here have posted that their performance (obviously) drops off when motors are switched out when faulty, which unless there are many more than one missing, may not be as noticeable on an 8-car set. When running without a full complement of motors, I believe that it imposed restrictions on climbing the 1:29 slopes in the core. The other issue as has been hinted at is that driver experience and or technique can make a considerable difference. The 319s have 300hp motors that if in serial mode do have the torque to easily spin the wheels until the anti-slip protection kicks in. Some drivers seemed to drive them on the limit of adhesion (which would seem to affect the 10-20mph range more) whereas others seem quite cautious up to about 30-40. Such differences could account for the apparent inconsistencies in the posted curves.

Completely agree with AM9's comments.

 

[gazthomas]

Yes it was.

Isn’t this topic about he 769 not MKC and Bedford fares

 

[yorkie]

Isn’t this topic about he 769 not MKC and Bedford fares

Agreed. I've split those posts into a new thread: https://www.railforums.co.uk/thread...-between-bedford-milton-keynes-london.159656/

If anyone wishes to go off on a tangent, or if anyone sees someone else go off topic and wishes to reply, please please create a new thread. It is much easier that people do this themselves than for us to split it.

 

[FordFocus]

Any updates on the flex program? Updated timelines would be appreciated. It's become a very long topic!!!

 

[D365]

In terms of product acceptance I don’t think I’ve heard anything about the 769 at work... the 230 in comparison sounds as if production is in full swing.

 

[fulmar]

Northern driver training on class 769s for those drivers working the Cumbria services has been cancelled as there are no units available to train on due to technical issues. I do not know what the technical issues are or when/if they are likely to be resolved. Instead, drivers working the Cumbria services who would have been trained on 769s are instead being trained on 158s ready for the May timetable change.

 

[D365]

... as there are no units available to train on due to technical issues.

There clearly aren’t, are there

 

[northwichcat]

Northern driver training on class 769s for those drivers working the Cumbria services has been cancelled as there are no units available to train on due to technical issues.

If a post by Tony Miles on wnxx is to be believed (based on his discussion with Ian Walmsley) the Flex plans presumed the 319s were in perfect condition but they aren't - there's steel components (which Porterbrook proposed fitting diesel engines to) which have worn so thin that they can't support the extra weight of a diesel engine.

 

[Bletchleyite]

If a post by Tony Miles on wnxx is to be believed (based on his discussion with Ian Walmsley) the Flex plans presumed the 319s were in perfect condition but they aren't - there's steel components (which Porterbrook proposed fitting diesel engines to) which have worn so thin that they can't support the extra weight of a diesel engine.

Does that mean the project becomes uneconomic, or will there just be delays while the components concerned have new bits welded in?

 

[northwichcat]

Does that mean the project becomes uneconomic, or will there just be delays while the components concerned have new bits welded in?

Unclear. Porterbrook are apparently not saying anything, while another poster on wnxx has suggested we won't see 769s in passenger service in 2018.

 

[doa46231]

I think I read somewhere that Ian Walmsley has made a bet that the 769's will never turn a wheel in anger!