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

[175001]

With the 195 cracks, they'll be needed don't worry

 

[Gricer99]

Will

590P 1845 Manchester Vic.(Rev.Sdg) to Southport
Departing today be the NH 769 on the way to Southport?​

 

[1D53]

Will

590P 1845 Manchester Vic.(Rev.Sdg) to Southport​

Departing today be the NH 769 on the way to Southport?​

Yes.

 

[Bertie the bus]

Deleted.

 

[Jamesrob637]

With the 195 cracks, they'll be needed don't worry

Well the social media team had better be prepared for loads of complaints if not!

 

[Grannyjoans]

Will the 769 be able to keep up to the 150/156 timings ?
The Sprinters are hard pushed as it is to keep to time on the Southport line. Especially when it is required to stop at all stops.
The 769s apparantly have even poorer acceleration, at least in Diesel mode.

 

[AM9]

Will the 769 be able to keep up to the 150/156 timings ?
The Sprinters are hard pushed as it is to keep to time on the Southport line. Especially when it is required to stop at all stops.
The 769s apparantly have even poorer acceleration, at least in Diesel mode.

Time will tell whether the different qualities of a DEMU with new diesel prime power give better performance than a 40+ year old traction system with a slushy hydraulic torque converter, especially once the drivers get to know them and have a free hand in controlling their different power characteristics.

 

[1Z99]

769434, 448, 431 and 450 all in passenger operation from today (as at 0200, Monday 17th May 2021).

Allocations as follows (ex-Southport);

2K81 0617 SOP-ALD - 769434
2K82 0716 SOP-ALD - 769424
2K83 0815 SOP-ALD - 769448
2K84 0917 SOP-ALD - 769431
2K85 1016 SOP-ALD - 769450

 

[TT-ONR-NRN]

769434, 448, 431 and 450 all in passenger operation from today (as at 0200, Monday 17th May 2021).

Allocations as follows (ex-Southport);

2K81 0617 SOP-ALD - 769434
2K83 0815 SOP-ALD - 769448
2K84 0917 SOP-ALD - 769431
2K85 1016 SOP-ALD - 769450

Hooray! We’ve waited long enough. I’ve got two days in Manchester next week and I look forward to trying them out.

 

[175001]

442 also booked to be out but first trip cancelled due to a fault. Possibly reinstated from Wigan to Stalybridge at 0808

 

[Gricer99]

Thanks. Looks like its just the Southport -Alderney Edge ones booked today.

 

[Boothby97]

Can confirm 769450 is out, just sighted on late running 2W02 0749 Alderley Edge to Southport.
Will admit I did doubt platform announcements when I thought what looked like a 319 pulled in on a Southport service, totally forgot about the 769s

 

[Purple Orange]

Can confirm 769450 is out, just sighted on late running 2W02 0749 Alderley Edge to Southport.
Will admit I did doubt platform announcements when I thought what looked like a 319 pulled in on a Southport service, totally forgot about the 769s

3 years late running!

 

[43102EMR]

3 years late running!

Weren’t they targeted for 2017, or was it 2018?

 

[37424]

Presumably these are meant to run on electric between Bolton and Alderley Edge?

Bi-modes comes to Northern but in true Northern style its a bodged up 30 year old train.

 

[Killingworth]

769434 delayed out of Alderley Edgec currently 14 minutes late at Wigan Wallgate. Running well.

 

[Neptune]

769434 delayed out of Alderley Edgec currently 14 minutes late at Wigan Wallgate. Running well.

Trains delayed through Stockport due to a pair of 331’s sitting down. No fault of the 769.

 

[Domh245]

Still has the old colour palette "n" s, though I don't suppose they're particularly high priority to be changed

 

[Geeves]

What ever was up with 769442 seems to be fixed as its on 1330 Staly - Southport

 

[Jamesrob637]

Trains delayed through Stockport due to a pair of 331’s sitting down. No fault of the 769.

Oh the irony!

 

[Neptune]

Oh the irony!

They sat down due to infrastructure failure.

 

[Grannyjoans]

Time will tell whether the different qualities of a DEMU with new diesel prime power give better performance than a 40+ year old traction system with a slushy hydraulic torque converter, especially once the drivers get to know them and have a free hand in controlling their different power characteristics.

Well, the main issue comes from the fact that the DEMU only has two diesel engines generating 1000hp, while the 150/156 has four diesel engines generating 1140hp and is a lighter train as well!

 

[CR165022]

769434 delayed out of Alderley Edgec currently 14 minutes late at Wigan Wallgate. Running well.

Nice to see the original n style still in place!

 

[1D53]

Trains delayed through Stockport due to a pair of 331’s sitting down. No fault of the 769.

Sitting down = having half the pan carbon ripped off by some damaged OHLE. Thankfully no serious damage!

 

[Gricer99]

Seemed to be on time mid morning.

 

[AM9]

Well, the main issue comes from the fact that the DEMU only has two diesel engines generating 1000hp, while the 150/156 has four diesel engines generating 1140hp and is a lighter train as well!

It actually a lot more subtle than simple Wikipedia data. The power transfer curve of electric generator + motor traction is totally different to that of a hydraulic transmission driven by a diesel engine. The two diesel engines only produce 1046hp between them at their output shafts, much the same as the class 150s which can only give 1144shp (shaft hp) from their combined efforts. It's what happens after that matters. A modern 3 phase generator will convert over 90% of its mechanical input power into electricity, and the engine can be run at its most efficient speed to generate that maximum power. The torque converter in a hydraulic transmission has a fairly restricted efficiency band and a lot of slippage when the load is stalled, (i.e. when starting from still) that wastes quite a large portion of the input energy. There are hydrulic experts here that can define the operation of a hydraulic drive far better than me. A traction motor however can provide maximum torque at very low speeds whilst the generator allows the engine to run at its optimum speed for power output. This is the main reason for all UK diesel freight locos being diesel electric.
All this adds up to far better control and use of the available output power, avoiding the noisy thrash you get when all that a sprinter driver can do is get the engine to stir the fluid up as fast as it can.

 

[scrapy]

13.30 Stalybridge to Southport (769442) and 14.50 Alderley Edge to Southport (769424) both delayed at Bolton this afternoon due to power switching issues.

 

[Foggycorner]

I was at Bolton today and saw the changeover on a few went smoothly as far as I could seeand there seemed to be no differance in running on electric from the pan or from the greaseburner underneath why should it its the same electric motors driving the train

 

[AM9]

I was at Bolton today and saw the changeover on a few went smoothly as far as I could seeand there seemed to be no differance in running on electric from the pan or from the greaseburner underneath why should it its the same electric motors driving the train

Precisely, and although the available electric power from the diesel genset is less than the transformer output, the take off from Bolton platforms probably feels just the same, maybe a bit noisier.

 

[Grannyjoans]

It actually a lot more subtle than simple Wikipedia data. The power transfer curve of electric generator + motor traction is totally different to that of a hydraulic transmission driven by a diesel engine. The two diesel engines only produce 1046hp between them at their output shafts, much the same as the class 150s which can only give 1144shp (shaft hp) from their combined efforts. It's what happens after that matters. A modern 3 phase generator will convert over 90% of its mechanical input power into electricity, and the engine can be run at its most efficient speed to generate that maximum power. The torque converter in a hydraulic transmission has a fairly restricted efficiency band and a lot of slippage when the load is stalled, (i.e. when starting from still) that wastes quite a large portion of the input energy. There are hydrulic experts here that can define the operation of a hydraulic drive far better than me. A traction motor however can provide maximum torque at very low speeds whilst the generator allows the engine to run at its optimum speed for power output. This is the main reason for all UK diesel freight locos being diesel electric.
All this adds up to far better control and use of the available output power, avoiding the noisy thrash you get when all that a sprinter driver can do is get the engine to stir the fluid up as fast as it can.

Whether 769 can match a 150 or not will be tested by whether the 769s are keeping to time on Southport to Wigan "all-stops"