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

[AlexNL]

However every AC EMU I can think of has a transformer in the same vehicle as the pantograph, with lower voltage bussed down the train for those units where the motors are elsewhere.

The TGV family of trains have a 25 kV cable running alongside the roof to supply the front power car ('motrice'). On high speed lines TGVs use only their rear pantograph for current collection.

 

[33021]

Pendolino 25kV runs between pantograph cars design to allow cross feed and redundancy

 

[The_Engineer]

Thread drift alert!!!

 

[The Lad]

I believe that BR tended to prefer having all the kit in one place. Spreading it around does potentially make for better performance.

 

[AM9]

I believe that BR tended to prefer having all the kit in one place. Spreading it around does potentially make for better performance.

But with the 319s, we are where we are, and it hasn't been a problem for 30 years. The extra load in the DTs might be a bit limiting, but should have been taken into consideration in their profiling. I would imagine that the lower torque available when running on diesel would limit wheelslip if they are driven carefully.

 

[EE Andy b1]

Were 319s fitted with sanding equipment?
This 769 is fitted on 3rd axle of each driving vehicle with sanders which might just be for braking but could now be used for traction as well which would help greatly.

 

[bengley]

Were 319s fitted with sanding equipment?
This 769 is fitted on 3rd axle of each driving vehicle with sanders which might just be for braking but could now be used for traction as well which would help greatly.

Yes, the 319s have sanders

 

[jopsuk]

Wasn't there a presumption of not bussing high (6.25/25kV) ac voltages in those days and routing low voltage ac from the transformer would be wasteful. The bussed DC had been the practice ever since the LSWR was electrified as a simple measure to reduce gapping.

The Mark 3 EMUs, as built, all have DC motors- it would have been very much possible to lay out a 317 in the same configuration as a 315, with a pantograph/transformer/rectifier on a trailer and two driving motors, plus a trailer with just the power bus through it. Indeed, the 455 of course has the DC pickups on the driving trailers, feeding the MSO (as does the 319). It's not clear why BREL took the step backwards from the DM-T-(T)-DM configuration to the DT-M-(T)-DT configuration between the PEP and Mark 3 generations, and really "step backwards" does seem appropriate given Networkers and later EMUs (and have a DC bus as there needs to be a smooth rectified DC step anyway in feeding AC power to AC motors)

 

[The_Engineer]

But with the 319s, we are where we are, and it hasn't been a problem for 30 years. The extra load in the DT might be a bit limiting, but should have been taken into consideration in their profiling. I would imagine that the lower torque available when running on diesel would limit wheelslip if they are driven carefully.

The Class 769 has been designed to have performance meeting or just exceeding timings for Class 150s.

It's not clear why BREL took the step backwards from the DM-T-(T)-DM configuration to the DT-M-(T)-DT configuration between the PEP and Mark 3 generations, and really "step backwards" does seem appropriate given Networkers and later EMUs (and have a DC bus as there needs to be a smooth rectified DC step anyway in feeding AC power to AC motors)

It was Southern region politics at the time which influenced Class 455 design very strongly, over-riding what Derby Tech Centre wanted. They had a very conservative Chief Engineer who didn't want anything modern (e.g. Chopper Control) on his region, just more of the same. Basically, Southern only wanted EE507 motors as fitted to all their other stock; they only took the PEP Class 508s as a stop-gap until they could quickly dispose of them as Class 455s arrived. The Southern even demanded that the same old fashioned traction control gear used on VEP and CIG stock was utilised on Class 455s, meaning GEC Traction had to blow off discontinued EE designs and even used refurbished equipment from 4-SUB stock!!

 

[AM9]

The Class 769 has been designed to have performance meeting or just exceeding timings for Class 150s. ...

That's fine but the point under discussion was the concentration of all the traction to the four axles in one car, and it's impact on adhesion when the trailing load is increased by two gensets located in the DTs. The current 319 EMUs can have problems accelerating on track with poor railhead conditions. My comment was that the lower torque (at low wheel speeds) when the motors are powered by the gensets may reduce the tendency for wheelslip (albeit with a lower rate of acceleration). In addition, bengley's post confirms the availability of sanding equipment which may further assist when pulling away with poor railhead conditions.

 

[driver_m]

Excellent decision to allow sanding to occur during acceleration instead of just braking. However, would the 769/319 have a decent amount in the sandbox to last the day?

 

[jopsuk]

It was Southern region politics at the time which influenced Class 455 design very strongly, over-riding what Derby Tech Centre wanted. They had a very conservative Chief Engineer who didn't want anything modern (e.g. Chopper Control) on his region, just more of the same. Basically, Southern only wanted EE507 motors as fitted to all their other stock; they only took the PEP Class 508s as a stop-gap until they could quickly dispose of them as Class 455s arrived. The Southern even demanded that the same old fashioned traction control gear used on VEP and CIG stock was utilised on Class 455s, meaning GEC Traction had to blow off discontinued EE designs and even used refurbished equipment from 4-SUB stock!!

But that doesn't fully explain it- the 317s were the first of the family, they set the template of having the motors on an intermediate car (with the pantograph, transformer and rectifier there too on the AC/DV versions)

 

[100andthirty]

That's fine but the point under discussion was the concentration of all the traction to the four axles in one car, and it's impact on adhesion when the trailing load is increased by two gensets located in the DTs. The current 319 EMUs can have problems accelerating on track with poor railhead conditions. My comment was that the lower torque (at low wheel speeds) when the motors are powered by the gensets may reduce the tendency for wheelslip (albeit with a lower rate of acceleration). In addition, bengley's post confirms the availability of sanding equipment which may further assist when pulling away with poor railhead conditions.

At low speed, it is expected that the motors will deliver the same torque on either supply - diesel or 25kV. It is the speed at which the torque starts to fall that will be lower when powered by the diesel engines. Sanders in motoring will, indeed, be useful.

As far as I recall it, the mk3 derived emus have one power car as the designers of the day deemed that this was all that was needed to meet the required performance, and it led to a cheaper train than the PEP derived trains which were deemed expensive. Of course, these trains are deemed underpowered when viewed through today's lens.

 

[AM9]

... As far as I recall it, the mk3 derived emus have one power car as the designers of the day deemed that this was all that was needed to meet the required performance, and it led to a cheaper train than the PEP derived trains which were deemed expensive. Of course, these trains are deemed underpowered when viewed through today's lens.

The class 319s not only managed well into the 21st century to run one of the most intensive services in the UK, but also shared running with inter-city services on a 100mph mainline. So their current/future use, e.g. as EMUs on the Chat Moss route/Bolton line should be well within their capability. As class 769s, progress will be slightly more sedate but almost anything that reduces the ridiculous practice of running diesel under wires can't be a bad thing.

 

[notlob.divad]

But the big question.... Has it moved yet?

 

[Journeyman]

I can't speak for the class number but I remember having explained on a depot visit that the oldest GE units were indeed DC units with transformers/rectifiers added to the existing control gear.

There were two classes of GE units converted from 1500v to 25kV, the sliding door 306s, dating from 1949, and the slam-door 307s dating from 1956. The latter units were for the extension from Shenfield to Southend. As originally constructed, both types had a single motor coach apiece, with the pantograph located on it. When rebuilt, the pantographs were relocated to adjacent trailers, with transformers added on those vehicles too - the transformers produced fixed 1500v outputs, routed directly into the original control circuits, keeping mods to a minimum. The pantographs were moved to different vehicles simply because the transformers are bulky and heavy, and there were space/weight issues placing them on the motor coaches.

 

[FenMan]

That's fine but the point under discussion was the concentration of all the traction to the four axles in one car, and it's impact on adhesion when the trailing load is increased by two gensets located in the DTs. The current 319 EMUs can have problems accelerating on track with poor railhead conditions. My comment was that the lower torque (at low wheel speeds) when the motors are powered by the gensets may reduce the tendency for wheelslip (albeit with a lower rate of acceleration). In addition, bengley's post confirms the availability of sanding equipment which may further assist when pulling away with poor railhead conditions.

Given some units are bound for the North Downs, I hope testing tries to replicate Down departures from Sandhurst during leaf fall season. The Turbos have lots of problems with wheel spin at this location.

 

[Greybeard33]

Press release from Skeleton Technologies:

Skeleton Technologies Signs Contract with Brush Traction to Supply Ultracapacitors for All BMU Class 769 Prime Movers

INNOTRANS Berlin, Germany, 18th of September 2018. Ultracapacitor European market leader Skeleton Technologies is now contracted to supply SkelStart Engine Start Module units on all Brush Traction Porterbrook Bi Mode Unit Class 769 flex prime movers.

The high-power density, inherent safety and tiny size of the 24V SkelStart module were decisive over other solutions during feasibility stage to start the Auxiliary Power Supply (APS) units. There was simply not enough allocated space available to integrate any other solution.

SkelStart is installed as a standalone starting powerpack with no power needed to top it up during standby periods as the case for long standby does not exist with this application. A Single Skelstart is powerful enough to start 27-liter engines at 20°C.

"We had limited space available for the integration of the APS starting power supply. The 24V SkelStart has the size of a regular car battery and with its 8kg weight, it solved the space restriction we had. Also, we do not need batteries for the APS start module as the BMU standby time is short. The expected lifetime of the SkelStart of at least 5 years also adds reliability to the system." said Mr. Chris Myatt, Engineering Director at Brush Traction.

Mr Taavi Madiberk, CEO of Skeleton Technologies added “It is a major stepping-stone for Skeleton Technologies to bring ultracapacitors to the rail industry. In this case, size matters, and the power density of our cells made the difference. Millions of rail passengers will benefit from our technology”

In this context Auxiliary Power Supply (APS) appears to refer to the diesel generator modules. Presumably the ultracapacitors will be used (instead of batteries) to start the diesel engines on transition to an unelectrified line.

It seems Brush uses the acronym "BMU" (Bi Mode Unit or Bi-mode Multiple Unit) to describe the 769, rather than EDMU.

If contracts are only now being awarded to suppliers of equipment needed on all production units, it perhaps suggests that deliveries are still many months away?

 

[Jonny]

Press release from Skeleton Technologies:

In this context Auxiliary Power Supply (APS) appears to refer to the diesel generator modules. Presumably the ultracapacitors will be used (instead of batteries) to start the diesel engines on transition to an unelectrified line.

It seems Brush uses the acronym "BMU" (Bi Mode Unit or Bi-mode Multiple Unit) to describe the 769, rather than EDMU.

If contracts are only now being awarded to suppliers of equipment needed on all production units, it perhaps suggests that deliveries are still many months away?

Maybe, but it sounds like a standard unit. Also there are usually auxiliary batteries on EMUs that could also be used to start the engines.

 

[Bertie the bus]

It’s a bit concerning they are only now signing contracts for components for trains which should have entered service 4 months ago.

 

[LowLevel]

But the big question.... Has it moved yet?

It's been hauled to Loughborough with it's barrier vehicles as of this morning. Whether it's moved under it's own power I have no idea.

 

[driver_m]

I'll just leave this here.... H-bomb version next!

https://www.railwaygazette.com/news...-train-demonstrator-to-be-tested-in-2019.html

UK: A memorandum of understanding for the development of a hydrogen fuel cell demonstrator train was signed by leasing company Porterbrook and the University of Birmingham’s Centre for Railway Research & Education at InnoTrans on September 19.

Porterbrook is to provide an ex-Thameslink Class 319 25 kV 50 Hz/750 V DC third rail electric multiple-unit for the Hydro Flex project. The partners expect it to be equipped with a fuel cell system and ready for demonstration runs in mid-2019. It would retain the ability to use electrical power.

Porterbrook CEO Mary Grant told Railway Gazettethat the company was aiming to innovate and look ahead to what what the railway industry will need 30 years in the future.

While electrification is likely to remain the optimal approach for busy inter-city routes, cost and practicality mean that there will be a need for self-powered trains long into the future, believes Helen Simpson, Engineering Supplier Development Manager at Porterbrook, and this is likely to require a mix of traction types.

Much of the interest in hydrogen power is because of its potential as a means of energy storage, Simpson explained. It could help to smooth national demand for electrical power by enabling power generated off peak to be used to produce hydrogen for later use.

This means that early applications of hydrogen trains could be in areas where there is hydrogen production infrastructure in place for other purposes.

There are currently no acceptance procedures in place for approving hydrogen trains for use in the UK, Simpson said, but this is not expected to be a problem for the project as there is industry-wide interest in developing hydrogen technology.

BCRRE has already undertaken research into the potential use of fuel cells in rail operations, and has worked with a number of global rail businesses to identify potential opportunities.

A team from BCRRE recently demonstrated a narrow-gauge locomotive powered by a fuel cell.

‘Hydrogen powered trains offer a cleaner alternative to current diesel trains and this project demonstrates the opportunities and value of innovation in the rail industry’, said Dr Stuart Hillmansen, Senior Lecturer in Railway Systems

 

[LOL The Irony]

Porterbrook is to provide an ex-Thameslink Class 319 25 kV 50 Hz/750 V DC third rail electric multiple-unit for the Hydro Flex project. The partners expect it to be equipped with a fuel cell system and ready for demonstration runs in mid-2019. It would retain the ability to use electrical power.

Of all the trains they can peddle, once again they choose one of the most unreliable trains on British rails as the basis of such a sham. Also, mid 2019 it'll be ready? You mean that'll be the earliest we'll see a flex in passenger service?

 

[mushroomchow]

What a joke. There's no way in a million years that they're going to have a hydrogen powered 769 operational by "mid-2019". We're still twiddling our thumbs, as of mid-September 2018, waiting to see a diesel version run under its own power. They would be mad to start a separate project with its own inevitable complications when they are seemingly still nowhere near meeting the commitments of the one they're currently mired in.

That said, is anybody down at the GCR today to see if the unit there has actually started testing? I imagine today will be the day if any if it has indeed moved to Loughborough.

 

[Bletchleyite]

Of all the trains they can peddle, once again they choose one of the most unreliable trains on British rails as the basis of such a sham. Also, mid 2019 it'll be ready? You mean that'll be the earliest we'll see a flex in passenger service?

It's one of the easiest to adapt as it has a third rail power system to feed into but also OHLE capability.

 

[LOL The Irony]

It's one of the easiest to adapt as it has a third rail power system to feed into but also OHLE capability.

It's also had 30 years of the elements to deal with.

 

[superkev]

It's one of the easiest to adapt as it has a third rail power system to feed into but also OHLE capability.

I wondered at the time if the lighter aluminium 313 types would have been a better bet.
K

 

[Bletchleyite]

I wondered at the time if the lighter aluminium 313 types would have been a better bet.

The other advantage of the 319 is that there's barely anything under 3 of the 4 coaches, so lots of room to fit engines etc. PEP EMUs have it more distributed with no large gaps.

 

[whhistle]

I wonder how much money would be saved using a train like this instead of just buying new; especially as now the CAF units have started mainline testing.

 

[bigyinn]

What a joke. There's no way in a million years that they're going to have a hydrogen powered 769 operational by "mid-2019". We're still twiddling our thumbs, as of mid-September 2018, waiting to see a diesel version run under its own power. They would be mad to start a separate project with its own inevitable complications when they are seemingly still nowhere near meeting the commitments of the one they're currently mired in.

Considering the amount of work already carried out on packaging the gensets etc, I see no reason why a hydrogen powered genset would be much harder to accomodate, given much of the work has already been done for the diesel versions.