GWR Class 769 information. (Units no longer with GWR - Off Lease March 23)

[spark001uk]

Obviously not. Platforms too short, no suitable locomotive and many other reasons.

It was a humorous offering.

 

[DorkingMain]

You can but you can also note that Thames & Chiltern in NSE days and Thames Trains / First Great Western / GWR have arguably done better by the route than any other operator would have done, both from a fares point of view and the service offered.


Obviously not. Platforms too short, no suitable locomotive and many other reasons.

SWR's only diesel fleet is based entirely at Salisbury, which I believe is the only place with the facilities to fuel and maintain diesels.

Southern by comparison services diesels at Selhurst which is not a prohibitive distance from the Redhill end of the line.

 

[cactustwirly]

SWR's only diesel fleet is based entirely at Salisbury, which I believe is the only place with the facilities to fuel and maintain diesels.

Southern by comparison services diesels at Selhurst which is not a prohibitive distance from the Redhill end of the line.

But it's not as convenient as Reading

 

[221101 Voyager]

Thought I'd share a couple of photos I have of these units.

Search: 769 GWR | Flickr

www.flickr.com

 

[Clarence Yard]

With GWR being fine (ignoring short HSTs being a short term solution) pre-covid I doubt the DfT are too interested in getting the 769s into service post covid.

They still seem to be - I suspect because they are paying for them!

In all seriousness, the sooner these things can get out of Reading depot and start their testing, the better.

 

[FenMan]

I agree the 769 should have been subjected to more rigorous prototype testing but, once again, the DfT had got themselves in a policy mess and went directly to authorising orders. If these things actually do the business and don’t slip themselves to a stand still on the North Downs, then all well and good.

Quite. I live on the Reading-Guildford stretch of the NDL and know all too well how 165/6s struggle when departing from Sandhurst towards Reading in greasy conditions.

I'd like to think the modelling of running 769s on the line would take slipping pinch-points fully into account. The proof of the pudding will be in the eating ...

 

[Vindaloo 42]

The problem I have with the 769s is they were designed to be the equivalent to a suburban 150.

I have no doubt 769s will work on suburban, low speed, short distance stopping services, e.g up to 30-40mph then coast to next station and brake, then repeat.

The problem I *do* have with them is using them on the North Downs Line, it's 60-70mph linespeed, long distances between stations, heavily graded and generally poor all year round adhesion. It's mainly forest, hills and valleys the whole route.

Anyone who knows how a 319 performs in adverse conditions will understand a 769 with added extra diesel weight and less available power/amps will not meet the criteria for the North Downs Line. Even the Turbos struggle on it on a bad day.

Bombardier announced a bimode Aventra about a year ago, since the GWML already has Crossrail 345s, GWR could order a bimode fleet to be used on Padd - Oxford switching modes at Didcot, the Thames branches, the North Downs Line and Reading - Basingstoke.

Send the GWR 387s to Southern for Uckfield Line electrification, or replacing Coastway 313s and Metro 455s.

 

[Wyrleybart]

The problem I have with the 769s is they were designed to be the equivalent to a suburban 150.

That is the problem. A class 150 has the driveline spread through the train with each car half powered (2 axles out of 4). The 769 has all four traction motors under the motor coach and nothing under the other three coaches. This inevitably means poor rail head conditions will be worse for the one car out of four, than for the 150, which being a four car would have twice as many powered axles spread through the unit.

But Porterbrook and Wabtec have clearly OK'd the design, so who are we to criticise.

I have no doubt 769s will work on suburban, low speed, short distance stopping services, e.g up to 30-40mph then coast to next station and brake, then repeat.

The problem I *do* have with them is using them on the North Downs Line, it's 60-70mph linespeed, long distances between stations, heavily graded and generally poor all year round adhesion. It's mainly forest, hills and valleys the whole route.

Anyone who knows how a 319 performs in adverse conditions will understand a 769 with added extra diesel weight and less available power/amps will not meet the criteria for the North Downs Line. Even the Turbos struggle on it on a bad day.

Bombardier announced a bimode Aventra about a year ago, since the GWML already has Crossrail 345s, GWR could order a bimode fleet to be used on Padd - Oxford switching modes at Didcot, the Thames branches, the North Downs Line and Reading - Basingstoke.

Send the GWR 387s to Southern for Uckfield Line electrification, or replacing Coastway 313s and Metro 455s.

The concern for me is whether NR agree to power changes on the move, and whether the 769 can actually do that. Is it capable of ceasing current draw from the 3rd rail and applying it's own diesel generated amps to the same traction motors whilst passing through the islands of 750V on the Reading-Redhill route ? Or can it only change mode whilst standing still ?

 

[800 Driver]

That is the problem. A class 150 has the driveline spread through the train with each car half powered (2 axles out of 4). The 769 has all four traction motors under the motor coach and nothing under the other three coaches. This inevitably means poor rail head conditions will be worse for the one car out of four, than for the 150, which being a four car would have twice as many powered axles spread through the unit.

But Porterbrook and Wabtec have clearly OK'd the design, so who are we to criticise.

The concern for me is whether NR agree to power changes on the move, and whether the 769 can actually do that. Is it capable of ceasing current draw from the 3rd rail and applying it's own diesel generated amps to the same traction motors whilst passing through the islands of 750V on the Reading-Redhill route ? Or can it only change mode whilst standing still ?

There's a reason they are not doing the testing in leaf fall season. Same reason they are doing signal sighting before the ASDO system is fitted into the cab. The 769 house of cards will fall down, preferably before they enter service, alternatively, shortly afterwards.

As for using the third rail system, it can only be used in a couple of areas where there is enough substation capacity, there's not enough available power in the majority of the third rail sections. I think it'll only be used Reading - Wokingham there's too much demand for DC juice in Guildford and Gatwick already.

 

[JonathanH]

As for using the third rail system, it can only be used in a couple of areas where there is enough substation capacity, there's not enough available power in the majority of the third rail sections. I think it'll only be used Reading - Wokingham there's too much demand for DC juice in Guildford and Gatwick already.

'Bald Rick' provided an assessment of the power supply in the '3tph on the North Downs Line' thread this week which debunks a bit of what you have suggested above.

https://www.railforums.co.uk/threads/3tph-on-north-downs-line.140595/page-38#post-5024146

Of the four electrified sections, IIRC:

Reading - Wokingham is specified to deal with 4 x 12 car trains each way an hour. If the uplift to 4 happens - which I very much doubt - then it is possible there needs to be some strengthening. If it doesn’t, then battery trains will be fine all day. They’ll be fine off peak regardless.

Aldershot South to Shalford Jn via Guildford - plenty spare, except perhaps in the Guildford station area.

Reigate - Redhill. Even if it’s a weak point (and I don’t know), there is electrical capacity for a 4 car service each way, which is all that could possibly operate.

Redhill - Gatwick. May need strengthening, but I struggle to believe that an extra two four cars in section at any one time could tip the line over the edge when there are routinely 10 x 12 car trains in the section concurrently without issue.

769s aren't to change power supply on the move.

 

[OTRail]

Do GWR plan on using the 769s on services to Paddington? If so wouldn’t that enable some service from Didcot to be extended to Oxford as per pre-electrification days?

 

[JonathanH]

Do GWR plan on using the 769s on services to Paddington? If so wouldn’t that enable some service from Didcot to be extended to Oxford as per pre-electrification days?

No. That isn't going to happen.

They wouldn't have anything like the performance needed to operate in between other trains out of Paddington.

 

[OTRail]

No. That isn't going to happen.

They wouldn't have anything like the performance needed to operate in between other trains out of Paddington.

Understandable given Reading stoppers are now with TfL Rail and the 387s are capable of 110mph

 

[anthony263]

769008 been fitted with new cab air cooling ive heard

 

[Vindaloo 42]

769008 been fitted with new cab air cooling ive heard

But that's not a GWR one? It's a TfW unit.

 

[JonathanH]

But that's not a GWR one? It's a TfW unit.

...and more to the point what has been fitted is presumably the same system fitted to the GWR units.

[There was a comment above about the air cooling not being effective.]

PS - you might want to correct the auto text

 

[OTRail]

But that's not a Jewish one? It's a TfW unit.

Regardless, shows that the fleet is having the cab air-con issue being addressed so there should be less issues bringing them into passenger service

 

[Southern Dvr]

are 769s planned for West Ealing to Greenford?
if so having them cleared to Paddington would make sense as they’d have to go at least as far as West Ealing. As mentioned in other places the amount of diesel that the Greenford branch requires with all day shuttling and associated ECS moves to and from Reading TMD is quite excessive.

 

[OTRail]

are 769s planned for West Ealing to Greenford?
if so having them cleared to Paddington would make sense as they’d have to go at least as far as West Ealing. As mentioned in other places the amount of diesel that the Greenford branch requires with all day shuttling and associated ECS moves to and from Reading TMD is quite excessive.

I think that will still be a Turbo given platform lengths at Greenford I heard

 

[JonathanH]

As mentioned in other places the amount of diesel that the Greenford branch requires with all day shuttling and associated ECS moves to and from Reading TMD is quite excessive.

There are no ECS moves. The Turbo for Greenford operates in service from Reading to Paddington at 0354 and Paddington to Oxford at 2315. No alternative propulsion is currently available between West Ealing and Greenford than diesel at present.

As noted, a 769 doesn't fit the platforms and, in any case, would potentially use more diesel than a Turbo shuttling between West Ealing and Greenford.

 

[Wyrleybart]

'769s aren't to change power supply on the move.

Which shows how restrictive the conversions are then ?
Thirty years ago Class 73s used to be able to transition quite easily, and used diesel on occasions to climb out of Victoria on the Gatexs before continuing on DC

But then that was under nasty old British Rail !!

 

[cactustwirly]

are 769s planned for West Ealing to Greenford?
if so having them cleared to Paddington would make sense as they’d have to go at least as far as West Ealing. As mentioned in other places the amount of diesel that the Greenford branch requires with all day shuttling and associated ECS moves to and from Reading TMD is quite excessive.

No they're not being used east of Maidenhead.
The only daytime branch getting them is the Henley line. With Maidenhead to Bourne End using them at peak times.

The only other lines are the Reading to Basingstoke and North Downs line

 

[OTRail]

No they're not being used east of Maidenhead.
The only daytime branch getting them is the Henley line. With Maidenhead to Bourne End using them at peak times.

The only other lines are the Reading to Basingstoke and North Downs line

I’m pretty sure they’re being used on the Slough to Windsor and Eton Central branch as well?

 

[JonathanH]

I’m pretty sure they’re being used on the Slough to Windsor and Eton Central branch as well?

No, if you read the thread, you will find that they aren't being used on the Windsor line.

https://www.railforums.co.uk/thread...mation-discussion.174866/page-15#post-4778221

The only routes the 769 units are due to enter service on are the North Downs, Basingstoke, Henley and to Bourne End in the peaks. 16 diagrams from 19 units. Originally the Windsor was going to be the 16th diagram but the 4th (peak) Basingstoke unit took that one away.

 

[Non Multi]

I’m pretty sure they’re being used on the Slough to Windsor and Eton Central branch as well?

Not enough units so the branch was was dropped from plans, see post #422 in this thread.

 

[Jamesrob637]

The problem I have with the 769s is they were designed to be the equivalent to a suburban 150.

I have no doubt 769s will work on suburban, low speed, short distance stopping services, e.g up to 30-40mph then coast to next station and brake, then repeat.

The problem I *do* have with them is using them on the North Downs Line, it's 60-70mph linespeed, long distances between stations, heavily graded and generally poor all year round adhesion. It's mainly forest, hills and valleys the whole route.

Anyone who knows how a 319 performs in adverse conditions will understand a 769 with added extra diesel weight and less available power/amps will not meet the criteria for the North Downs Line. Even the Turbos struggle on it on a bad day.

Bombardier announced a bimode Aventra about a year ago, since the GWML already has Crossrail 345s, GWR could order a bimode fleet to be used on Padd - Oxford switching modes at Didcot, the Thames branches, the North Downs Line and Reading - Basingstoke.

Send the GWR 387s to Southern for Uckfield Line electrification, or replacing Coastway 313s and Metro 455s.

Isn't Reading to Guildford a slightly drier part of the land than Wilmslow to the Fylde Coast? So if Northern examples won't struggle with adhesion, GWR's examples won't be too bad either.

 

[JN114]

The North Downs route is one of the worst for Autumn adhesion issues in the country. I wouldn’t say it’s particularly bad outside Autumn though.

 

[starlightEXPRESS]

Isn't Reading to Guildford a slightly drier part of the land than Wilmslow to the Fylde Coast? So if Northern examples won't struggle with adhesion, GWR's examples won't be too bad either.

The foot of the North Downs is a notorious frost pocket. Cold air rolls off the top of the hills and collects in the valley at the bottom (called the Vale of Holmesdale). The NDL runs along this valley for most of the distance between Guildford and Redhill.

In addition, the two rivers (Wey and Mole) that the line crosses, provide plenty of mist and moisture.

This picture is taken from the southern edge of the North Downs near Dorking, and shows how cold, damp air collects below the hills: https://www.flickr.com/photos/colin...TkLS-PdEWqF-8RYDT-8jKZ6u-pdecUR-oVXJkW-oW1Wx5

 

[Chriso]

Will these be operated with guard on the Henley line or remain DOO?

 

[JN114]

As currently equipped the 769s are not capable of DOO(P) operation.

We will have to wait and see what that means for the Henley branch, which hasn’t had guards in nearly 30 years now.