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

[Bletchleyite]

The only potential issue was that in a 3rd rail area, would there need to be some system to prevent back-flow from a "flex" with the generator(s) running onto the 3rd rail itself?

What, like a double-pole isolating switch? Not exactly the height of modern technology there

 

[HSTEd]

You would probably also need to limit the maximum current demanded by the traction package when on diesel power, so as not to exceed what the diesels can supply. Otherwise if the driver selected maximum power when on diesel, the DC bus voltage would just drop until something shut down or tripped out. Also necessary to consider what happens if one of the two diesel gensets is offline.

The specification requires that current draw be suppressed below 600vDC when operating on third rail, probably to prevent a chain reaction overload/trip.

You could set up your generators so they will be able to use such a thing to ensure they never trip out without modifying the existing traction system.

 

[AM9]

The only potential issue was that in a 3rd rail area, would there need to be some system to prevent back-flow from a "flex" with the generator(s) running onto the 3rd rail itself?

Given that the modification will be using new components, the diesel engine will drive a three-phase ac generator. This will feed a rectifier stack to create the DC fed to the bus. That stack, plus any control electronics will maintain the bus at 750v or less by controlling the generator excitation to:

a) feed the hotel services
and
b) feed the dc-dc converters for the traction circuits.​

The presence of the rectifiers will prevent any DC from either the 3rd rail or transformer from reaching the generator. The generator control electronics will reduce the generator excitation to prevent it feeding the 3rd rail.

 

[edwin_m]

The specification requires that current draw be suppressed below 600vDC when operating on third rail, probably to prevent a chain reaction overload/trip.

You could set up your generators so they will be able to use such a thing to ensure they never trip out without modifying the existing traction system.

Presuming you're referring to the spec for the traction package, that sounds as if it would do the job without having to change the existing equipment.

 

[edwin_m]

Given that the modification will be using new components, the diesel engine will drive a three-phase ac generator. This will feed a rectifier stack to create the DC fed to the bus. That stack, plus any control electronics will maintain the bus at 750v or less by controlling the generator excitation to:

a) feed the hotel services
and
b) feed the dc-dc converters for the traction circuits.​

The presence of the rectifiers will prevent any DC from either the 3rd rail or transformer from reaching the generator. The generator control electronics will reduce the generator excitation to prevent it feeding the 3rd rail.

I think you'd still need a circuit breaker between the generator and the bus and between the bus and the shoegear if third rail operation was still permitted. Otherwise the generator and electronics become safety critical because of the hazard of the generator feeding power into the third rail which might, for example, have been isolated for staff protection.

 

[northwichcat]

If what's been posted on another forum is true Northern have submitted a plan to DfT which will see a Stalybridge-Victoria-Bolton-Wigan and Wigan-Bolton-Piccadilly-Alderley Edge services operated using 319 Flexs and 4 car DMUs, with the DMU workings extended to Southport at peak times. The post also claims Northern want to use 319 Flexs on Southport services instead of Windermere services, subject to DfT approval.

 

[Bletchleyite]

If what's been posted on another forum is true Northern have submitted a plan to DfT which will see a Stalybridge-Victoria-Bolton-Wigan and Wigan-Bolton-Piccadilly-Alderley Edge services operated using 319 Flexs and 4 car DMUs, with the DMU workings extended to Southport at peak times. The post also claims Northern want to use 319 Flexs on Southport services instead of Windermere services, subject to DfT approval.

That is potentially a very good fit indeed - Southport isn't and doesn't need to be Northern Connect - what is basically a double Class 150 is a very well suited unit to that route, given that what it might well feature today is, err, a double Class 150.

 

[HSTEd]

Presuming you're referring to the spec for the traction package, that sounds as if it would do the job without having to change the existing equipment.

Yes, that current restriction is in the standard for 3rd rail traction systems on trains - or at least was circa 1997.

 

[Class 170101]

Has there been anymore on this?

 

[LNW-GW Joint]

The Porterbrook Class 319 Flex bi-mode conversion is to be Class 769, according to June's Modern Railways (p85).
Maybe the Stadler Flirt bi-modes for GA will have a similar class number.

 

[D6975]

The Porterbrook Class 319 Flex bi-mode conversion is to be Class 769, according to June's Modern Railways (p85).
Maybe the Stadler Flirt bi-modes for GA will have a similar class number.

Class number for the flirts has already been allocated - 755

3 car sets will be 755 301-14
4 car sets will be 755 401-24

 

[childwallblues]

I can understand the converted units being renumbered but why the 700 series?

 

[northwichcat]

I can understand the converted units being renumbered but why the 700 series?

Indeed. I thought electric trains with diesel engines were being given numbers in the 800 series.

 

[swt_passenger]

Indeed. I thought electric trains with diesel engines were being given numbers in the 800 series.

There's also a high speed aspect to the Class 800 definition: "High speed multiple unit / fixed formation sets". So as I see it a 100 mph EMU would not ever be an 8XX.

There was no class number defined (in the most recent group standard) for an AC unit with a diesel alternator backup. But 700 is fine for an AC EMU that is not "high speed".

However high speed seems undefined. AIUI some of the future 125 mph EMUs, e.g. for TPE, are staying with 3XX numbers. They should logically be 8XX.

 

[northwichcat]

There's also a high speed aspect to the Class 800 definition: "High speed multiple unit / fixed formation sets".

There was no class number defined (in the most recent group standard) for an AC unit with a diesel alternator backup. But 700 is fine for an AC EMU that is not "high speed".

However high speed seems undefined. AIUI some of the future 125 mph EMUs, e.g. for TPE, are staying with 3XX numbers. They should logically be 8XX.

I think the TPE 397s will have a maximum speed of 125mph, while the Hitachi IEP would be able to operate at 140mph if they were being used on a route which allowed speeds of >125mph.

 

[swt_passenger]

I think the TPE 397s will have a maximum speed of 125mph, while the Hitachi IEP would be able to operate at 140mph if they were being used on a route which allowed speeds of >125mph.

A respectable theory, but then the 'high speed' is defined elsewhere in the standard as "capable of operating at speeds in excess of 190 km/h" - so 118 mph?.

Beats me how they decide. As we already know they don't need to use 7XX for new EMUs either, as there are still 3XX class numbers spare; and any existing are reusable once the previous class has been out of service for a while...

 

[D365]

The 7xx range is turning out to be a complete mess...

 

[507021]

The Porterbrook Class 319 Flex bi-mode conversion is to be Class 769, according to June's Modern Railways (p85).
Maybe the Stadler Flirt bi-modes for GA will have a similar class number.

That seems like an odd choice, I think 319/9 or 819 would have been better. Oh well, they're only unit numbers.

 

[SpacePhoenix]

The 7xx range is turning out to be a complete mess...

Are either the 6xx or 9xx ranges reserved for any particular types of stock?

 

[najaB]

Are either the 6xx or 9xx ranges reserved for any particular types of stock?

9xx is reserved for NR departmental stock.

 

[swt_passenger]

Are either the 6xx or 9xx ranges reserved for any particular types of stock?

Here's the full list to save anyone having to look it up:

Diesel mechanical / hydraulic multiple unit sets 100 – 199

Diesel electric multiple unit sets 200 – 299

Diesel multiple unit sets 600 – 699

d.c. electric multiple unit sets 400 – 599

a.c. and a.c. / d.c. electric multiple unit sets 300 – 399

a.c. and a.c. / d.c. electric multiple unit sets 700 – 799

High speed multiple unit / fixed formation sets 800 – 899

Infrastructure maintenance / non-passenger multiple unit / fixed formation sets 900 – 999

That's the same order as given in table A.5 of GMRT2453, you'll see that 6XX is for new DMUs of unspecified type.

https://www.rssb.co.uk/rgs/standards/GMRT2453 Iss 2.pdf

 

[cjmillsnun]

Here's the full list to save anyone having to look it up:

Diesel mechanical / hydraulic multiple unit sets 100 – 199

Diesel electric multiple unit sets 200 – 299

Diesel multiple unit sets 600 – 699

d.c. electric multiple unit sets 400 – 599

a.c. and a.c. / d.c. electric multiple unit sets 300 – 399

a.c. and a.c. / d.c. electric multiple unit sets 700 – 799

High speed multiple unit / fixed formation sets 800 – 899

Infrastructure maintenance / non-passenger multiple unit / fixed formation sets 900 – 999

That's the same order as given in table A.5 of GMRT2453, you'll see that 6XX is for new DMUs of unspecified type.

https://www.rssb.co.uk/rgs/standards/GMRT2453 Iss 2.pdf

But that doesn't quite work as 450 and 444 are ac/dc capable EMUs (the same as 377 and 375 Electrostars without pantographs fitted), so technically should be 3XX.

 

[northwichcat]

Do despite the lack of a Civity family of DMUs currently a 600 number wasn't obtained for the new Northern DMUs, while the Desiro City got a 700 number despite there being class 350 and 360 Desiros and unallocated numbers starting 35 and 36. :roll:

 

[swt_passenger]

But that doesn't quite work as 450 and 444 are ac/dc capable EMUs (the same as 377 and 375 Electrostars without pantographs fitted), so technically should be 3XX.

Well quite. That seems to have been a widely understood point even at the time of the DC Desiro introduction, and the necessity for the full 400-599 range to be available for pure DC EMUs that will probably never be built again is highly questionable.

But I just wanted to explain what the current position is, not pick the obvious holes in hit. Someone has after all reserved another 100 class numbers for DMUs, even though at the time of publication (in 2011) the general assumption was that very few new DMUs would ever be needed...

 

[swt_passenger]

Do despite the lack of a Civity family of DMUs currently a 600 number wasn't obtained for the new Northern DMUs, while the Desiro City got a 700 number despite there being class 350 and 360 Desiros and unallocated numbers starting 35 and 36. :roll:

Well yes, and I also remember the Thameslink insider (who no longer posts) insisting against the tide of opinion that the whole of the 7XX series was reserved for Desiro City style units because they were somehow special.

 

[61653 HTAFC]

There's also a high speed aspect to the Class 800 definition: "High speed multiple unit / fixed formation sets". So as I see it a 100 mph EMU would not ever be an 8XX.

There was no class number defined (in the most recent group standard) for an AC unit with a diesel alternator backup. But 700 is fine for an AC EMU that is not "high speed".

However high speed seems undefined. AIUI some of the future 125 mph EMUs, e.g. for TPE, are staying with 3XX numbers. They should logically be 8XX.

And that's where you've gone wrong... looking for logic in the numbering system!

 

[jopsuk]

There have been brief pockets of logic in the class numbering system, but the last stock to follow any sort of logic seem to have been the Networkers

 

[Islineclear3_1]

Getting back on topic, any updates as to the status of 319.456 or any other units please?

 

[507021]

Getting back on topic, any updates as to the status of 319.456 or any other units please?

319434 and 319456 are still at Loughborough, I don't think any others have joined them yet.

Any guesses on their future numbers? I'll go for 769034 and 769056...

 

[Brian Aylott]

319434 and 319456 are still at Loughborough, I don't think any others have joined them yet.

Any guesses on their future numbers? I'll go for 769034 and 769056...

Wrong
Brian