Transport for Wales 769's

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From any perspective this is not going well. How many units are now considered reliable? How far is this from being considered a failed project, albeit with no alternative at present?!
 

PHILIPE

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Of all three 769s that have been in traffic (either originals or replacements) at some time today, they have now all fallen by the wayside.
 

Envoy

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Well, I suppose that if we were going to have this awful virus, that it could not have come at a better time for TfW.
 

Wyrleybart

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From any perspective this is not going well. How many units are now considered reliable? How far is this from being considered a failed project, albeit with no alternative at present?!

Think it depends whether you are in the industry and which company you work for, or whether you are able to look at the project from "over the fence" so to speak. Really, the 769 is the solution to a problem which hasn't been defined yet, although some will offer their version of it.

One of the Northern fleet was allocated today on a multi leg diagram from Allerton to Carnforth and Warrington, but not sure if it was more successful than the TfW units which are ironically theoretically simpler through being a pure DEMU with no power switching.

Gonna be really interesting to observed the GWR units switching between 750V and diesels.
 

Cardiff123

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From any perspective this is not going well. How many units are now considered reliable? How far is this from being considered a failed project, albeit with no alternative at present?!
Looking at this from a layman's POV, if I was TfW, I'd want abandon the 769 farce and scoop up the remaining 153s that have been sent off lease by EMR & WMR in the last few months, and run those in multiple on Penarth - Rhymney rather than faff around with 769s any longer. At least 153s are proven to actually reliably work. Obviously some would need to be PRM modified, with or without toilets.

But far too much time, effort and money has been invested in the 769 project to just abandon it now. That's ignoring the fact that the 769 project utterly failed at meeting its primary objective, which was to facilitate ATW/TfW in PRM-ing the 150s in time for 1/1/2020.

Plus there would be an enormous amount of face lost by both the TOCs and Porterbrook by just abandoning the 769 project now.
 

Caaardiff

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The issue now though is these units have been running around for nearly a year whether ECS or in passenger service, and the reliability hasn't been great.
So even if TfW continue with the 769, what's to say the reliability doesn't improve and punctuality takes a nose dive on that route?
We're getting ever closer to the point where these units are required for reliable service. When travel recommences and the timetable ramps up again, whether commuters will return to travel in big numbers or not, there may not be spare 150s or 153s to recover the service.
 

Greybeard33

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Mainly engine faults I think. The 319s were never great for reliability but they were better than 142/143/150/153.
I have no idea what issues TfW are experiencing, but I would not jump to the conclusion they are all down to the new gensets.

When Northern first introduced 319s their reliability was awful - far worse than it had been with Thameslink and far worse than Northern's 14x/15x DMUs. It has since gradually improved, suggesting it takes time for a new maintenance depot to get to grips with the quirks and foibles of these thirty year old units.

The TfW units were in storage a long time before re-entering service as 769s - that won't have helped.
 

AM9

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Mainly engine faults I think. The 319s were never great for reliability but they were better than 142/143/150/153.
What do you mean by "engine faults"? If it's the diesel engine in the gensets then as 319s, they didn't have any and they are new hardware anyway. The motors and their drive electronics are getting on but surely that is more a maintenance issue.
 

Bikeman78

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What do you mean by "engine faults"? If it's the diesel engine in the gensets then as 319s, they didn't have any and they are new hardware anyway. The motors and their drive electronics are getting on but surely that is more a maintenance issue.
As far as I'm aware, most of the faults with the 769s are to do with the new equipment that has been fitted. Obviously they can still have all the usual faults that 319s had, e.g. door faults. As 319s they had an MTIN of 10-12,000 miles on Thameslink. Not great but better than most DMUs.
 

Bikeman78

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What are the 170s MTIN? 10 000 is very low, didn't the 350s get around 120 000?
Looking at Modern Railways.
WMT 319s 12,127
Northern 319s 9,800

170s vary a lot.
Crosscountry 20,598
WMT 18,822
Scotrail 11,512
Northern 8,402
TfW 5,264

You are right about the 350s but don't forget the Silverlink 321s used to be top of the table. Close to 100,000 I think.

Of course the irony is that the 442s were slagged off as being very unreliable on the Brighton line but their MTIN was actually better than the 319s!
 

southern442

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Looking at Modern Railways.
WMT 319s 12,127
Northern 319s 9,800

170s vary a lot.
Crosscountry 20,598
WMT 18,822
Scotrail 11,512
Northern 8,402
TfW 5,264
Interesting that the most unreliable class 170s are the ones that have recently moved. This perhaps goes some way to credit the theory that cascaded stock experience teething troubles when they are moved.
 

craigybagel

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Interesting that the most unreliable class 170s are the ones that have recently moved. This perhaps goes some way to credit the theory that cascaded stock experience teething troubles when they are moved.
Possibly. But I wonder how well those 170s compared to the others when they were with their previous operator?
 

AM9

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As far as I'm aware, most of the faults with the 769s are to do with the new equipment that has been fitted. Obviously they can still have all the usual faults that 319s had, e.g. door faults. As 319s they had an MTIN of 10-12,000 miles on Thameslink. Not great but better than most DMUs.
If it's the engines themselves then that is a problem that belongs to Porterbrook, or ultimately MAN as the engines are a) proven in rail use and b) nearly new, (probably still within any warranty period that they had).
If on the other hand there are issues with the control and management of the engines, then that would be a Brush Traction responsibility as it was them that designed and tested the power-sharing control that fixed the original problems of the two engines interacting whilst supplying power to the DC bus.
I doubt that the DC traction system (bus/PWM electronics/motors) themselves would be creating problems as even if the drivers drove the trains hard, the motors could only get about 60-70% of the power that would be available to them as EMUs as it is be limited by the genset outputs.
 

samuelmorris

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Just from the video footage alone, the 769s don't seem to behave like other DMUs as far as engine speeds are concerned. If there are reliability issues related to the engines, I almost guarantee it'll be their implementation, e.g. how they are mounted, cooled, or controlled, that is the issue, not the units themselves.
 

samuelmorris

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In what way does their behaviour seem different to you?
Use of higher than normal (in some case full) engine speeds when decelerating or when stopped. There aren't a lot of regular runs of 769s on youtube and of course I haven't ventured down to Wales during lockdown to see for myself, but there's definitely been something odd about the way they behave up until now.
 

Bletchleyite

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Just from the video footage alone, the 769s don't seem to behave like other DMUs as far as engine speeds are concerned.

They should behave like Voyagers (their fellow DEMUs) or diesel FLIRTs? If they are running when the train is decelerating or not moving, this will I guess because of something else drawing power, e.g. topping up starting batteries, running the air compressors or whatever? Indeed, is what you are hearing the air compressor (which can sound a bit like a diesel engine on older EMUs) and not the engine at all?

Interesting that the most unreliable class 170s are the ones that have recently moved. This perhaps goes some way to credit the theory that cascaded stock experience teething troubles when they are moved.

Happens a lot. Reliability of 321s went through the floor when they moved to Northampton from Bletchley, for instance, though it picked back up again when they got used to them.
 

samuelmorris

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They should behave like Voyagers (their fellow DEMUs) or diesel FLIRTs? If they are running when the train is decelerating or not moving, this will I guess because of something else drawing power, e.g. topping up starting batteries, running the air compressors or whatever? Indeed, is what you are hearing the air compressor (which can sound a bit like a diesel engine on older EMUs) and not the engine at all?



Happens a lot. Reliability of 321s went through the floor when they moved to Northampton from Bletchley, for instance, though it picked back up again when they got used to them.
Yes, but idle speed (or a little above it) should be ample for that. DMUs tend not to idle as slowly as other commercial vehicles due to the reasons you cited, but there's still a substantial drop in engine speed (and thus noise) when they aren't under power.

It's definitely engine noise - listen to the both power cars in this example - particularly noticeable with the rear power car. Both engines are running at almost full speed until the unit comes to a complete stop.

The timestamp you want is 6m15 - xenforo tends to strip those out when linking timestamped youtube videos.

 

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