Transport for Wales 769's

[AM9]

They have 25 less horsepower than a 150 per car (50hp less for a 4 car train) and they can only do 75mph so 100mph on diesel is going to have to be downhill and even then will be a struggle.

For comparison they have halve the power of a 195 which has 523hp per car while the 769 has 523hp for 2 cars.

The horsepower that you refer to is the peak output of the diesel engines, (which will be over a fraction of the engine speed range). When driven hard, the 150s torque converters take a considerable proportion of that power, mostly generating heat in their hydraulic fluid. The engine speed also varies much more as the train progresses through the gears and the operating temperature curve of the transmission, so it is not always going to be runing at it's peak power level.
The 769s though, whilst having a slightly lower gross engine power output (about 8.5% less), it has less power loss than the 150's hydraulic transmission over the rail speed range, and a greater torque figure when needed. On the 769s, the diesel engine can run at any speed in range irrespective of rail speed. Their motors are under driven (below 79% of their continuous rating) so even allowing for their age, they are unlikely to pose any constraint on performance at any temperature.The estimate weight of the the 769s is about 16t over the 319/150 tare weight so that additional load would ultimately have a slight effect on acceleration but in terms of their maximum speed, as EMUs they are capable of 100mph on level track (just - I have clocked them at that), and it was stated somewhere here that the prototype 769 achieved about 90mph in diesel mode. The 150s of course are limited by design to a maximum of 75mph.

 

[Bikeman78]

They keep to the timetable quite nicely. Once they get to 15mph they go really well

The timetable has 60 seconds at every station and two or three minutes at some, e.g. Queen Street, Caerphilly. No surprise they can keep to time. The Pacers and 150s easily managed to keep time off peak on the pre Covid timetable where most station dwell were 30 seconds.

 

[Greybeard33]

Theory...

The horsepower that you refer to is the peak output of the diesel engines, (which will be over a fraction of the engine speed range). When driven hard, the 150s torque converters take a considerable proportion of that power, mostly generating heat in their hydraulic fluid. The engine speed also varies much more as the train progresses through the gears and the operating temperature curve of the transmission, so it is not always going to be runing at it's peak power level.
The 769s though, whilst having a slightly lower gross engine power output (about 8.5% less), it has less power loss than the 150's hydraulic transmission over the rail speed range, and a greater torque figure when needed. On the 769s, the diesel engine can run at any speed in range irrespective of rail speed. Their motors are under driven (below 79% of their continuous rating) so even allowing for their age, they are unlikely to pose any constraint on performance at any temperature.The estimate weight of the the 769s is about 16t over the 319/150 tare weight so that additional load would ultimately have a slight effect on acceleration but in terms of their maximum speed, as EMUs they are capable of 100mph on level track (just - I have clocked them at that), and it was stated somewhere here that the prototype 769 achieved about 90mph in diesel mode. The 150s of course are limited by design to a maximum of 75mph.

... versus the real world experience of a Northern driver:

In reply to some of the recent posts - line speed doesn't come in to it, they're barely capable of anything above 60-70mph anyway. 769s can't reach the maximum line speed of 70 on the Southport line which has no gradient for the most part.

I know which I believe!

 

[Anonymous10]

Theory...

... versus the real world experience of a Northern driver:

I know which I believe!

shocker a electric unit converted to diesel ( means less room for engines you would think) is slower

 

[Nymanic]

"Significantly slower than Porterbrook's own projections" is the issue here, not simply "slower than electric".

Whatever your opinions of the 769 concept, if it fails to keep to the timings of 35-year old DMUs with slower (theoretical) top speeds, it's a poor advertisement and a poor fit.

 

[Bikeman78]

"Significantly slower than Porterbrook's own projections" is the issue here, not simply "slower than electric".

Whatever your opinions of the 769 concept, if it fails to keep to the timings of 35-year old DMUs with slower (theoretical) top speeds, it's a poor advertisement and a poor fit.

Agreed. I've been saying this since day one having travelled on them on a route I know very well. I'm sure the passengers on the North Downs Line will have a lovely surprise when they start running there.

 

[_toommm_]

Agreed. I've been saying this since day one having travelled on them on a route I know very well. I'm sure the passengers on the North Downs Line will have a lovely surprise when they start running there.

Especially if GWR and TfW have the same policy as Northern that the power notches must be used sequentially, and you can’t jump straight to Notch Two

 

[samuelmorris]

The only footage I've seen of 769s at present shows acceleration suggesting a top speed of perhaps 60 tops without tens of miles between stops. If there's an example somewhere that shows something more like the expectations set by Porterbrook, I'd certainly be interested to see it.

 

[craigybagel]

The only footage I've seen of 769s at present shows acceleration suggesting a top speed of perhaps 60 tops without tens of miles between stops. If there's an example somewhere that shows something more like the expectations set by Porterbrook, I'd certainly be interested to see it.

To be fair, they're only working Penarth - Rhymney at present and very little of that route has a linespeed higher than 60 anyway. It's also very hilly at both ends. Other then the section downhill from Heath to Queen Street I doubt a 150 would get over 60 on that route either.

 

[Bob Price]

These units were brought in for capacity to enable the 150's to be refurbished. They have shown they can easily keep time so not sure there is a big issue from a user pov. However if the Stadlers can't keep pace then there is a problem.

 

[JN114]

I think there’s a stark disconnect between what members here seem to expect of the 769s, and what the manufacturer and promoter (Wabtec-Faiveley and Porterbrook respectively) have billed them to operators as.

They were billed as BiMode equivalents to a 4 car Cl150 - which doesn’t get far north of 70mph either. For the most part the 769s appear to broadly match that billing. They are a tad slower, but not unreasonably so.

There are a lot of elements of the introduction that has left a lot to be desired - some of it outside their control, but some very much in. Reliability hasn’t been there and there’s rumours - and I confess only rumours - that they’re not meeting fuel range expectations, both of which cause headaches for operators.

The shiny new products from Stadtler brought in by Greater Anglia are evidently superior at doing a similar job; but I’m sure there’d be similarly huge outrage amongst the membership here and the wider enthusiast community if all Sprinter-Generation stock was scrapped nationally and replaced with new builds.

For TfW they’re in, they’re doing the job they’re designed to reasonably well, reliability will come with time.

 

[Bletchleyite]

These units were brought in for capacity to enable the 150's to be refurbished. They have shown they can easily keep time so not sure there is a big issue from a user pov. However if the Stadlers can't keep pace then there is a problem.

FLIRTs are very quick off the mark indeed, you'd not know it was a DMU.

 

[PHILIPE]

These units were brought in for capacity to enable the 150's to be refurbished. They have shown they can easily keep time so not sure there is a big issue from a user pov. However if the Stadlers can't keep pace then there is a problem.

Are you sure ? I thought they were brought in to enable the withdrawal of Pacers until new stock became available. Refurbishments are usually catered for within the existing fleet and not by anything additional.

 

[Energy]

Are you sure ? I thought they were brought in to enable the withdrawal of Pacers until new stock became available. Refurbishments are usually catered for within the existing fleet and not by anything additional.

5 were ordered by ATW to cover for refurbishments, TfWRS subsiquently added 4 more units to help replace the pacers (the 170s and 230s also are replacing pacers)

 

[Mrs. Fortescue]

Saw 003 out in service this morning. Amazing how quiet they are compared to the 150s.

 

[samuelmorris]

I think there’s a stark disconnect between what members here seem to expect of the 769s, and what the manufacturer and promoter (Wabtec-Faiveley and Porterbrook respectively) have billed them to operators as.

They were billed as BiMode equivalents to a 4 car Cl150 - which doesn’t get far north of 70mph either. For the most part the 769s appear to broadly match that billing. They are a tad slower, but not unreasonably so.

There are a lot of elements of the introduction that has left a lot to be desired - some of it outside their control, but some very much in. Reliability hasn’t been there and there’s rumours - and I confess only rumours - that they’re not meeting fuel range expectations, both of which cause headaches for operators.

The shiny new products from Stadtler brought in by Greater Anglia are evidently superior at doing a similar job; but I’m sure there’d be similarly huge outrage amongst the membership here and the wider enthusiast community if all Sprinter-Generation stock was scrapped nationally and replaced with new builds.

For TfW they’re in, they’re doing the job they’re designed to reasonably well, reliability will come with time.

It's certainly fair not expect EMU performance from DMUs, and I only expect DMU performance of 769s, of course. Genuinely though, the performance of 769s I've seen thus far is more like that of full-length loco hauled stock consists, Sprinters are far quicker. If it just so happens that all the units that have been captured on video have been in reduced power settings then fair enough, I've just yet to see any evidence of a 769 performing anywhere near the standard of a 150, let alone a Stadler unit.

 

[Bikeman78]

I think there’s a stark disconnect between what members here seem to expect of the 769s, and what the manufacturer and promoter (Wabtec-Faiveley and Porterbrook respectively) have billed them to operators as.

They were billed as BiMode equivalents to a 4 car Cl150 - which doesn’t get far north of 70mph either. For the most part the 769s appear to broadly match that billing. They are a tad slower, but not unreasonably so.

There are a lot of elements of the introduction that has left a lot to be desired - some of it outside their control, but some very much in. Reliability hasn’t been there and there’s rumours - and I confess only rumours - that they’re not meeting fuel range expectations, both of which cause headaches for operators.

The shiny new products from Stadtler brought in by Greater Anglia are evidently superior at doing a similar job; but I’m sure there’d be similarly huge outrage amongst the membership here and the wider enthusiast community if all Sprinter-Generation stock was scrapped nationally and replaced with new builds.

For TfW they’re in, they’re doing the job they’re designed to reasonably well, reliability will come with time.

When you get the chance, I suggest having a go on one. They really are slow! I'm not convinced they would win a race against a class 205 DEMU.

 

[Caaardiff]

The whole point of the 769 introduction is to meet capacity demands, not speed demand. Which is what they are (or will be doing).
The speed comparison is only because of the luxury of having 150s on the routes which are a perfect fit. The timings as such should be reflected in the timetable and would very much likely have been tested by TfW to ensure accuracy. Don't forget the 170s haven't exactly been a good match for the routes they are doing and the timetable had to be amended to accommodate them. But again, they are doing the job intended, increasing capacity.

As for the reliability, I'd put that into question. Personally I think TfW in their desperation have taken on dogs. Over a year delayed and still not providing a reliable service, and only 3-4 of the units which are actually suitable for passenger service. The work that has been required to be done by Canton to get these things up to scratch is unacceptable and should have been sorted by Porterbrook before coming to TfW.

 

[AM9]

... The work that has been required to be done by Canton to get these things up to scratch is unacceptable and should have been sorted by Porterbrook before coming to TfW.

Do we know whether Porterbrook are underwriting the cost of the Canton work, which might be easier to integrate with the driver training programme in the current situation?

 

[43096]

As for the reliability, I'd put that into question. Personally I think TfW in their desperation have taken on dogs. Over a year delayed and still not providing a reliable service, and only 3-4 of the units which are actually suitable for passenger service. The work that has been required to be done by Canton to get these things up to scratch is unacceptable and should have been sorted by Porterbrook before coming to TfW.

How do we know it isn’t Canton who have broken them? It’s not like Canton Car Sheds have a stellar reputation for maintenance.

 

[Caaardiff]

How do we know it isn’t Canton who have broken them? It’s not like Canton Car Sheds have a stellar reputation for maintenance.

Maybe, maybe not, its doubtful we'll know. But what I do know is TfW have an ageing fleet that is still running, mainly, if not exclusively down to Canton.
The latest 153s arrived in what TfW deemed an unsuitable state to put in service, which meant a lot of work needed to get them up to standard, which puts into question the maintenance of the previous operators those 153s were with.

 

[Llama]

Especially if GWR and TfW have the same policy as Northern that the power notches must be used sequentially, and you can’t jump straight to Notch Two

That policy is nonsense, nobody on Northern drives them like that and nobody was trained to drive them like that.

 

[Rhydgaled]

FLIRTs are very quick off the mark indeed, you'd not know it was a DMU.

FLIRTs, the UK ones at least, are all diesel-electric (which we tend to refer to as DEMUs). Does having the wheels driven by traction motors instead of gears make a difference all else being equal?

Are you sure ? I thought they were brought in to enable the withdrawal of Pacers until new stock became available. Refurbishments are usually catered for within the existing fleet and not by anything additional.

Refurbishments don't usually have to be rushed to meet a legal compliance deadline. By being able to take more units out of service at a time for refurbishment, PRM mods could theoretically be completed sooner. Not sure if that's why the 769s were ordered or whether it was to make a start on scrapping Pacers but it's a possiblity.

 

[Energy]

Does having the wheels driven by traction motors instead of gears make a difference all else being equal?

Seems to, the Voyagers also accelerate very well.

 

[Anonymous10]

FLIRTs, the UK ones at least, are all diesel-electric (which we tend to refer to as DEMUs). Does having the wheels driven by traction motors instead of gears make a difference all else being equal?


Refurbishments don't usually have to be rushed to meet a legal compliance deadline. By being able to take more units out of service at a time for refurbishment, PRM mods could theoretically be completed sooner. Not sure if that's why the 769s were ordered or whether it was to make a start on scrapping Pacers but it's a possiblity.

or it could have been both as we know tfw were keeping pacers till 150s were prm whatever happened so possibly it was to cover for 150s then replace pacers

 

[Caaardiff]

or it could have been both as we know tfw were keeping pacers till 150s were prm whatever happened so possibly it was to cover for 150s then replace pacers

The initial directive was that no non PRM unit was allowed to be in service after a certain date. (Of which I forget the actual date). Originally the 150s were expected to have the mods done by this date or not be allowed in service.
So as per the PRM requirements only PRM compliant 150s and original 153s would have been allowed in service after that date.
The 150 refurb program would have a limit to how many could be done at any one time as it wasn't ATW/TfW completing the refurbs, it was a dedicated team Arriva Train Care Crewe

 

[Wyrleybart]

The initial directive was that no non PRM unit was allowed to be in service after a certain date. (Of which I forget the actual date). Originally the 150s were expected to have the mods done by this date or not be allowed in service.
So as per the PRM requirements only PRM compliant 150s and original 153s would have been allowed in service after that date.
The 150 refurb program would have a limit to how many could be done at any one time as it wasn't ATW/TfW completing the refurbs, it was a dedicated team Arriva Train Care Crewe

IIRC all non PRM stock was to have been stood down by 2359 on 31/12/2019.
In the case of TfW rolling stock there have been several excuses blaming variously TfW WAG, Arriva and the DfT. I really don't know what to believe but 142 and 143 were never going to be PRM modded, neither I think were any, or at least many 153s. PRM work was heavily delayed as was the Flex project, so the 769s weren't able to release the 150s or the 14x anyway.

The point though is, the Flex project is a different beast for each of the three customers. TfW units have been delivered without 25kV capability, neither have they been factory liveried nor accumulated mileage prior to entry into traffic. As opposed to the Northern fleet which saw FFR by ROG staff. The GWR 769s appear to have been liveried at the factories prior to despatch to the Reading, similar to the Northern fleet to Allerton or Edge Hill. The question begs whether Pullman Rail or Wabtec staff are doing the business at Canton.

The thing that blows me away though is the class 769 used to be a 100mph dual voltage EMU. Adding diesel traction to the EMU theoretically made the units self propelled. Despite that each of the 36 units seems to have needed diesel hauling or delivered by road because they apparently cannot be driven on NR metals.
Is the paperwork really so difficult ?

 

[43096]

FLIRTs, the UK ones at least, are all diesel-electric (which we tend to refer to as DEMUs).

Except for the electric only ones.

 

[Bob Price]

The thing that blows me away though is the class 769 used to be a 100mph dual voltage EMU. Adding diesel traction to the EMU theoretically made the units self propelled. Despite that each of the 36 units seems to have needed diesel hauling or delivered by road because they apparently cannot be driven on NR metals.
Is the paperwork really so difficult ?

The initial one was, I have video of it. However there were some issues with physical clearance en route in the Midlands which meant they had to be road delivered.

 

[Bletchleyite]

Except for the electric only ones.

Indeed. In essence they're an EMU with a generator added - very similar to a 769 really.