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

[Class455]

A signalling interference issue at Manchester Oxford Road occurred recently, which was resolved by the 769 in the station dropping its pan and continuing onwards using diesel mode.

Could that be why a 769 I had today (769442) ran in diesel mode between Manchester Victoria and Bolton instead of putting the pan up?

 

[Greybeard33]

A signalling interference issue at Manchester Oxford Road occurred recently, which was resolved by the 769 in the station dropping its pan and continuing onwards using diesel mode.

A little puzzling that a 769 in AC mode should have this issue at Oxford Road, when 319s have operated through the station in AC mode for many years.

 

[507020]

A massive notice on the booking on desk at our signing on point.

That’s not good news

== Doublepost prevention - post automatically merged: 23 May 2022 ==

Could that be why a 769 I had today (769442) ran in diesel mode between Manchester Victoria and Bolton instead of putting the pan up?

Yes. The Alderley Edge services were cancelled 4 hours in a row today with only the Stalybridge services running. For 769s on these it’s not even really worth putting the pan up.

 

[Wilts Wanderer]

I imagine this will have serious fuel-range implications for those sets that are in traffic, as well as problems maintaining timings on the nominally electric sections?

 

[Geeves]

Control are swapping them around to get them to Newton Heath (etc) for fuel more frequently as of today.

424 is being rescued tonight by 458 (which also has fault meaning it cant be used in service) and both will go back to Allerton tonight. 424 has been in the reverse sidings at Victoria for about a week with a demic engine... Which means it has to go back in electric mode tonight...

 

[175001]

I imagine this will have serious fuel-range implications for those sets that are in traffic, as well as problems maintaining timings on the nominally electric sections?

We've been told they are good for 600 miles.

And no, performance in diesel mode is just a stood as in electric, up to about 70mph. Then it struggles. But we can't do more than 75 in them between Crescent and Bolton anyway

 

[Class455]

We've been told they are good for 600 miles.

And no, performance in diesel mode is just a stood as in electric, up to about 70mph. Then it struggles. But we can't do more than 75 in them between Crescent and Bolton anyway

I thought 769442 performed rather well in diesel mode, and was hitting good speeds on my journey today. Although as you say you can't go above 75 in them between Salford Crescent and Bolton and they're not running on lines which have a max speed of 100mph anyway.

It's a shame they're having so many issues really, as when they actually work they are decent units.

 

[Greybeard33]

I thought 769442 performed rather well in diesel mode, and was hitting good speeds on my journey today. Although as you say you can't go above 75 in them between Salford Crescent and Bolton and they're not running on lines which have a max speed of 100mph anyway.

It's a shame they're having so many issues really, as when they actually work they are decent units.

Cheadle Hulme - Alderley Edge is a mix of 100 and 110.

 

[507020]

I thought 769442 performed rather well in diesel mode, and was hitting good speeds on my journey today. Although as you say you can't go above 75 in them between Salford Crescent and Bolton and they're not running on lines which have a max speed of 100mph anyway.

It's a shame they're having so many issues really, as when they actually work they are decent units.

Salford Crescent - Euxton Junction has been MU 100 since electrification a while ago but I went on a Pendolino that way a few weeks ago and it couldn’t go above 75 either. I want to know if GWR 769s will go above 75 on the Brighton main line between Redhill and Gatwick Airport.

 

[TurboMan]

I want to know if GWR 769s will go above 75 on the Brighton main line between Redhill and Gatwick Airport.

Yes, they'll do 90 at a push. But that's in DC mode, not diesel, if that's what you were wondering.

 

[craigybagel]

Cheadle Hulme - Alderley Edge is a mix of 100 and 110.

True, but the stations are so close together that even on electric a 769 is going to struggle to get over 75 there.

Salford Crescent - Euxton Junction has been MU 100 since electrification a while ago but I went on a Pendolino that way a few weeks ago and it couldn’t go above 75 either. I want to know if GWR 769s will go above 75 on the Brighton main line between Redhill and Gatwick Airport.

Was it ever confirmed if the 75 mph restriction is actually a local instruction or is it just that they can't run at MU speeds? If the BML is 90 for everything (and I'm reasonably sure it is) then hopefully they will indeed be allowed run at those speeds?

 

[Greybeard33]

True, but the stations are so close together that even on electric a 769 is going to struggle to get over 75 there.

A 769 on AC indeed has poor acceleration, as does a 319, but these are very sluggish units compared with modern EMUs such as the 331. Even 323s, with only a 90mph top speed, easily outperform 319s on stopping services.

== Doublepost prevention - post automatically merged: 24 May 2022 ==

Was it ever confirmed if the 75 mph restriction is actually a local instruction or is it just that they can't run at MU speeds? If the BML is 90 for everything (and I'm reasonably sure it is) then hopefully they will indeed be allowed run at those speeds?

It is interesting that, in the current timetable, the Alderley Edge services are still pathed as a 319 EMU at 100mph between Bolton and Manchester, even though all the units that work them (769 and 15x) are restricted to 75mph.

 

[Llama]

Salford Crescent - Euxton Junction has been MU 100 since electrification a while ago but I went on a Pendolino that way a few weeks ago and it couldn’t go above 75 either. I want to know if GWR 769s will go above 75 on the Brighton main line between Redhill and Gatwick Airport.

769s and 390s can't obey MU speeds. Apologies if you are already aware of this.

 

[WAO]

A 769 on AC indeed has poor acceleration, as does a 319, but these are very sluggish units compared with modern EMUs such as the 331. Even 323s, with only a 90mph top speed, easily outperform 319s on stopping services.

== Doublepost prevention - post automatically merged: 24 May 2022 ==


It is interesting that, in the current timetable, the Alderley Edge services are still pathed as a 319 EMU at 100mph between Bolton and Manchester, even though all the units that work them (769 and 15x) are restricted to 75mph.

I'm not sure that it's quite fair to call 319/769's very sluggish. They are after all express not suburban units in SR speak with traction motor gear ratios to suit. Those familiar with the Southern Region Mark 1 units will be aware of the two gear ratios; 65/17 and 61/19 for 75 and 90 mph stock respectively. You trade top speed for low speed acceleration. Modern units (post-privatisation) have much higher installed power (that caused mayhem with the power supplies) and inverter drives. They are therefore better all round performers but at a cost....

It's just a pity that they didn't iron out the problems before introducing the tri-mode version.

WAO

 

[AM9]

I'm not sure that it's quite fair to call 319/769's very sluggish. They are after all express not suburban units in SR speak with traction motor gear ratios to suit. Those familiar with the Southern Region Mark 1 units will be aware of the two gear ratios; 65/17 and 61/19 for 75 and 90 mph stock respectively. You trade top speed for low speed acceleration. Modern units (post-privatisation) have much higher installed power (that caused mayhem with the power supplies) and inverter drives. They are therefore better all round performers but at a cost....

It's just a pity that they didn't iron out the problems before introducing the tri-mode version.

WAO

To do that on the 769s would involve changing the drive train including the pinion on the axles. Hardly worth it for the flex programme.

 

[apk55]

A 319 only has 1/4 axles motored and I do not think it uses the full available adhesion very well. Many modern units have 1/2 axles motors and work at higher adhesion levels helped by electronic controls.

Maybe they could consider doing a re motoring exercise such as done with the class 455 - the equipment used on those units could the job.

 

[AM9]

A 319 only has 1/4 axles motored and I do not think it uses the full available adhesion very well. Many modern units have 1/2 axles motors and work at higher adhesion levels helped by electronic controls.

Maybe they could consider doing a re motoring exercise such as done with the class 455 - the equipment used on those units could the job.

The 319s (even when converted to 769s) have a unique electronic traction system featuring GTO thyristors owing to their original ac OLE/DC 3rd rail modes of operation. The remotored 455 trains are 3rd rail DC only, so transferring the kit over when the 455s are scrapped might not be as easy as it seems.

 

[Peter Sarf]

769 movements are now to run in diesel mode throughout and must not be used in AC mode until further notice apparently.

Source?

A signalling interference issue at Manchester Oxford Road occurred recently, which was resolved by the 769 in the station dropping its pan and continuing onwards using diesel mode.

That explains why I noticed all the 769s I saw at Manchester Piccadilly on Tuesday 24/05/2022 had their pans down !.

As for poorer performance under diesel and fuel range this could be resolved by removing heavy/bulky things like transformers !. I'll get my coat.

 

[507020]

Yes, they'll do 90 at a push. But that's in DC mode, not diesel, if that's what you were wondering.

Was it ever confirmed if the 75 mph restriction is actually a local instruction or is it just that they can't run at MU speeds? If the BML is 90 for everything (and I'm reasonably sure it is) then hopefully they will indeed be allowed run at those speeds?

I was wondering whether 75mph Bolton - Salford Crescent was either a local restriction on 769s or a local restriction on MU timings, which I believe it is, so I do want to see whether they are cleared for 90mph on DC on the BML.

A 769 on AC indeed has poor acceleration, as does a 319, but these are very sluggish units compared with modern EMUs such as the 331. Even 323s, with only a 90mph top speed, easily outperform 319s on stopping services.

What about a 319/769 on DC? 323s are very much acceleration units with very impressive acceleration, but 313/507/314/508/315s also have vastly superior acceleration to 319s despite being 10 years older.

769s and 390s can't obey MU speeds. Apologies if you are already aware of this.

I was, but thank you for the clarification.

As for poorer performance under diesel and fuel range this could be resolved by removing heavy/bulky things like transformers !. I'll get my coat.

This is very much an option. Transformers aren’t used at all when not in AC mode and are easily removable for replacement in case one fails, so if AC mode is temporarily banned, transformers and/or pantographs perhaps should be removed to improve Diesel performance/range. This would also prevent drivers from inadvertently using AC mode despite the instruction not to.

 

[AM9]

What about a 319/769 on DC? 323s are very much acceleration units with very impressive acceleration, but 313/507/314/508/315s also have vastly superior acceleration to 319s despite being 10 years older.

323s are geared for 90mph and are genuine metro toastracks of the '90s. 319s are 1980's 100mph outer suburban DC motored trains. They can't be sensibly compared on acceleration.
313/507/314/508/315s are all 75mph geared and designed for frequent stops. They would have fared very poorly on the MML.

This is very much an option. Transformers aren’t used at all when not in AC mode and are easily removable for replacement in case one fails, so if AC mode is temporarily banned, transformers and/or pantographs perhaps should be removed to improve Diesel performance/range. This would also prevent drivers from inadvertently using AC mode despite the instruction not to.

Removing an EMU transformer as a temporary measure makes no difference. The suspension is set up for the weight of the transformer, so would need to be substituted by an equivalent lump of concrete, (AFAIK that was the case on the SWML class 444s and 450s).

 

[Greybeard33]

Removing an EMU transformer as a temporary measure makes no difference. The suspension is set up for the weight of the transformer, so would need to be substituted by an equivalent lump of concrete, (AFAIK that was the case on the SWML class 444s and 450s).

Indeed so. And the 319/769 transformer and pantograph are in the motor coach, which has the only driven axles. The weight is needed to minimise the risk of wheelslip during acceleration.

 

[AM9]

Indeed so. And the 319/769 transformer and pantograph are in the motor coach, which has the only driven axles. The weight is needed to minimise the risk of wheelslip during acceleration.

Yes, that's why the 319 MSO weighs over 50t and as an EMU has over 36% adhesive weight.

 

[swt_passenger]

Indeed so. And the 319/769 transformer and pantograph are in the motor coach, which has the only driven axles. The weight is needed to minimise the risk of wheelslip during acceleration.

AIUI the SWR units do not have a lump of concrete. It’s why the PTSO is significantly lighter than the 350 equivalent. We had a thread about it a few years ago, and it turned out Bombardier and Siemens did not follow the same approach.

 

[507020]

AIUI the SWR units do not have a lump of concrete. It’s why the PTSO is significantly lighter than the 350 equivalent. We had a thread about it a few years ago, and it turned out Bombardier and Siemens did not follow the same approach.

How do 450s and 444s have PTSO vehicles when they don’t carry pantographs?

 

[swt_passenger]

How do 450s and 444s have PTSO vehicles when they don’t carry pantographs?

They have a pantograph well, and Siemens include the letter “P” on the relevant carriage designation on its data plate.

 

[59CosG95]

They have a pantograph well, and Siemens include the letter “P” on the relevant carriage designation on its data plate.

Precisely; 350s are just 450s with a transformer and a pantograph (and no shoegear on all but 30).

 

[507020]

They have a pantograph well, and Siemens include the letter “P” on the relevant carriage designation on its data plate.

Precisely; 350s are just 450s with a transformer and a pantograph (and no shoegear on all but 30).

They were ordered as 450s for SWT, with only passive provision for AC i.e. a pantograph well and space for a transformer, so if they weren’t intended to run on AC initially, why would they be designed to carry a heavy concrete block around everywhere? Then some were of course diverted to the WCML and pantographs and transformers were fitted to the existing DC EMU cars that had been built by Siemens.

 

[TurboMan]

I do want to see whether they are cleared for 90mph on DC on the BML.

Yes they are. There is no differential speed restriction, it's 90 on both fast and slow.

== Doublepost prevention - post automatically merged: 25 May 2022 ==

This is very much an option. Transformers aren’t used at all when not in AC mode and are easily removable for replacement in case one fails, so if AC mode is temporarily banned, transformers and/or pantographs perhaps should be removed to improve Diesel performance/range. This would also prevent drivers from inadvertently using AC mode despite the instruction not to.

That would be an awful lot of work. The far easier option is to isolate the air supply to the pan, which is what GWR have in place when an AC restriction is applied to a 769.

 

[507020]

Yes they are. There is no differential speed restriction, it's 90 on both fast and slow.

But have they run at that speed there, or anywhere else since they had Diesel engines fitted?

That would be an awful lot of work. The far easier option is to isolate the air supply to the pan, which is what GWR have in place when an AC restriction is applied to a 769.

That is perhaps a better idea if you want to prevent drivers accidentally switching to AC mode, but does nothing to reduce dead weight.

 

[Greybeard33]

AIUI the SWR units do not have a lump of concrete. It’s why the PTSO is significantly lighter than the 350 equivalent. We had a thread about it a few years ago, and it turned out Bombardier and Siemens did not follow the same approach.

350s/450s are not equivalent to 319s/769s. They have two motor coaches, with twice as many driven axles, and the transformer is in a trailer car, where it does not contribute to adhesive weight.