Transport for Wales 769's

[AM9]

I was in one of the non-engine coaches. Once it was up to speed, it was very quiet.

Was it the pantograph car, - if so then most of the starting noise would have been from the motors, (magnetostriction of the case, and the drive pinions) and the transformer, (a 100Hz hum/buzz) that eventually is masked by the other motor noises.
If it was a continuous note from starting at about 400Hz (notes Gsharp or Bflat), then it would be the traction electronics.

 

[Bikeman78]

I would imagine that the internal environment depends quite a bit on which coach you're in.

Every carriage has a different sound. The two outer cars have the diesel engines which are quite quiet. One of the intermediate cars has the four DC traction motors. If I recall correctly, the fourth car has the air compressor.

I had a ride on 769002. The interior is spotless and the train smells brand new. From the middle of the train, the diesel engines were barely audible, it just sounded like a 319. They won't be setting any speed records. It took 1:39 to get through Caerphilly tunnel. That's about the same as a 153 or 37418 when it had the low power fault. A decent 37 will do it in 1:30 and a Pacer in 1:25. I'll try again when the drivers are more used to them.

On arrival at Rhymney. 769002 went to the sidings and was replaced by a triple 153. There was no fault with the 769 but the line was closed late morning for NR to fix an axle counter fault. This meant that the 769 could not have run to Rhymney on its seconds trip so the 153s come out three hours early.

 

[Domh245]

and the transformer, (a 100Hz hum/buzz) that eventually is masked by the other motor noises.

Surely there would be no transformer buzz in these units, being exclusively diesel (read 750v DC) powered?

 

[Bikeman78]

Surely there would be no transformer buzz in these units, being exclusively diesel (read 750v DC) powered?

They still make the humming sound as heard at the 11 second mark on this video of 319372 departing from Flitwick. I think it's the thyristor control? Worth noting that a 769 doesn't accelerate anywhere near this fast!

 

[Domh245]

They still make the humming sound as heard at the 11 second mark on this video of 319372 departing from Flitwick. I think it's the thyristor control? Worth noting that a 769 doesn't accelerate anywhere near this fast!

Like @AM9 notes, there's two possible buzzing noises - the thyristor/motor controller buzz and the transformer. It's just about audible on the video you link that the buzzing suddenly shifts up in tone from the low transformer buzz around the 10 second mark to the higher thyristor buzz at 11 seconds. Based on everything we've been told about these units, only the thyristor buzz should be heard

 

[craigybagel]

I had a ride on 769002. The interior is spotless and the train smells brand new. From the middle of the train, the diesel engines were barely audible, it just sounded like a 319. They won't be setting any speed records. It took 1:39 to get through Caerphilly tunnel. That's about the same as a 153 or 37418 when it had the low power fault. A decent 37 will do it in 1:30 and a Pacer in 1:25. I'll try again when the drivers are more used to them.

Given both the time of year and the current weather, I suspect any train would struggle for performance, but especially one where only two bogies out of 8 are powered. The difference might not be so noticeable outside of slippy season.

 

[konstant]

The noise people are hearing and complaining about after leaving a station is the compressor rattling on startup to replenish air lost in the on boarding process.

Some units have newer resilient mounts than others and so some shake like hell and some don’t - word on the street is that a campaign change will be on the cards sooner than later for the mounts.

 

[Bletchleyite]

Well, the body shells are basically the same but all of that hanging below the floor isn't.

In the sense of it being a DMU (DEMU) based on a Mk3 bodyshell it's pretty close. Though of course the engine is newer and it has unpowered vehicles. I suppose it's like a 150/210 hybrid.

 

[AdamWW]

In the sense of it being a DMU (DEMU) based on a Mk3 bodyshell it's pretty close. Though of course the engine is newer and it has unpowered vehicles. I suppose it's like a 150/210 hybrid.

I think having the traction motors on a separate vehicle to the diesel engine is unusual.

(Didn't the Blue Pullman sets have one powered bogie at each end under a non-engined vehicle, though?)

 

[samuelmorris]

Was it the pantograph car, - if so then most of the starting noise would have been from the motors, (magnetostriction of the case, and the drive pinions) and the transformer, (a 100Hz hum/buzz) that eventually is masked by the other motor noises.
If it was a continuous note from starting at about 400Hz (notes Gsharp or Bflat), then it would be the traction electronics.

Pedantry, but G sharp is (equivalent to) A flat, not B flat, and the noise in question is actually 300Hz, or D sharp / E flat.

As pointed out above, the 100Hz buzz produced by the transformer will be absent on a 769 when on diesel power. No bad thing as some Mk3 EMUs, such as the 322 I’m on right now, are horrendous for it and the vibration seems to hit every bone in your body!

 

[Bikeman78]

Like @AM9 notes, there's two possible buzzing noises - the thyristor/motor controller buzz and the transformer. It's just about audible on the video you link that the buzzing suddenly shifts up in tone from the low transformer buzz around the 10 second mark to the higher thyristor buzz at 11 seconds. Based on everything we've been told about these units, only the thyristor buzz should be heard

I can confirm there is no transformer buzz on a 769 running on diesel.

 

[norbitonflyer]

I think having the traction motors on a separate vehicle to the diesel engine is unusual.

(Didn't the Blue Pullman sets have one powered bogie at each end under a non-engined vehicle, though?)

They did - the leading two vehicles each had one power bogie (2-Bo+Bo-2)

== Doublepost prevention - post automatically merged: 16 Nov 2020 ==

This is, I believe, the first new class to enter service since Class 397, in November last year. If, indeed, it can really be called new.

 

[AM9]

I can confirm there is no transformer buzz on a 769 running on diesel.

Ooops, yes we're talking about class 769/0s which on delivery at least will not run on OLE. So they would sound more like a 319 on 3rd rail.

 

[AdamWW]

Ooops, yes we're talking about class 769/0s which on delivery at least will not run on OLE. So they would sound more like a 319 on 3rd rail.

They certainly won't without pantographs.

 

[AM9]

They certainly won't without pantographs.

Which is a shame.

 

[Bikeman78]

They certainly won't without pantographs.

I'm told that all the other 25kV equipment is still in situ so the pantographs can easily be put back on if required.

 

[AM9]

I'm told that all the other 25kV equipment is still in situ so the pantographs can easily be put back on if required.

I've heard that as well. There could be scope for them to run under wires in south Wales if necessary.
I know that the 3rd rail shoes were regularly removed and stored, only to be replaced every time that they moved over routes not cleared for them.

== Doublepost prevention - post automatically merged: 16 Nov 2020 ==

Pedantry, but G sharp is (equivalent to) A flat, not B flat, and the noise in question is actually 300Hz, or D sharp / E flat. ...

Yes, I was trying to be clever and insert the 'b' like character normally used on staves, using Windows Character Map.
Not a musician, but I've long known that A above middle C is 436 or 440 Hz, so I had to look up for notes around 400Hz.

 

[AdamWW]

I've heard that as well. There could be scope for them to run under wires in south Wales if necessary.
I know that the 3rd rail shoes were regularly removed and stored, only to be replaced every time that they moved over routes not cleared for them.

== Doublepost prevention - post automatically merged: 16 Nov 2020 ==

I don't supposed constantly putting the diesels on and off for the intermittent electrification planned for the Valleys would be too great an idea, though.

Especially if what I read is true that one of the places they plan to leave live wires out of is stations.

Does anyone know if one is out again today for passengers to have a go on?

 

[anthony263]

769002 should be out today

 

[LNW-GW Joint]

First 769 running in anger.

So that's nearly 4 years since the Flex project was kicked off (by DfT/Porterbrook/Northern) in December 2016.
And 7 months less for this diesel-only WG project which started in July 2017.
Meanwhile, the railway landscape has changed completely.
I guess the original aim (to replace non-compliant Pacers) still exists.

 

[Bletchleyite]

So that's nearly 4 years since the Flex project was kicked off (by DfT/Porterbrook/Northern) in December 2016.
And 7 months less for this diesel-only WG project which started in July 2017.
Meanwhile, the railway landscape has changed completely.
I guess the original aim (to replace non-compliant Pacers) still exists.

There's still a DMU shortage. Though will the impending release of TfW's 158s and 175s solve that for good?

Could I suppose scrap some 150s and 156s to replace with those units with more modern engines. And Northern are still running DMUs under wires which was part of the rationale for it.

 

[Wyrleybart]

So that's nearly 4 years since the Flex project was kicked off (by DfT/Porterbrook/Northern) in December 2016.
And 7 months less for this diesel-only WG project which started in July 2017.
Meanwhile, the railway landscape has changed completely.
I guess the original aim (to replace non-compliant Pacers) still exists.

Might be wrong but I thought the Raison d etre for the TfW 769s was to temporarily cover the 150/2s and the 140x on the Rhymney line, so that the TfW DMU fleet could be released for PRM'ing. That didn't happen and TfW had to PRM the units with the help of some Porterbrook loan 153s.

I was under the impression the 769s were an interim provision for TfW but am not sure how they intend to use all nine, particularly as it is only Rhymney conductors who currently sign them.

Lets hope the actually deliver reliability for TfW and prove the concept.

 

[Bob Price]

There must have been a reason for the extra order for the 769's. Perhaps the plan was Rhymney to Penarth would be 100% 769's?

== Doublepost prevention - post automatically merged: 17 Nov 2020 ==

Notice 5Z53 also on the diagrams. Are they running one and testing another?

 

[anthony263]

Think the plan is to have at least 1 class 769 in service with a 2nd joining it before December and another on test/training.

However things could change so we'll just have to wait and see

 

[PHILIPE]

There must have been a reason for the extra order for the 769's. Perhaps the plan was Rhymney to Penarth would be 100% 769's?

== Doublepost prevention - post automatically merged: 17 Nov 2020 ==

Notice 5Z53 also on the diagrams. Are they running one and testing another?

5Z53 is not a diagram Bob, but a Train identification. A diagram is the pre-planned full days work for a unit. There is one out in service and another out training.

 

[Cardiff123]

Might be wrong but I thought the Raison d etre for the TfW 769s was to temporarily cover the 150/2s and the 140x on the Rhymney line, so that the TfW DMU fleet could be released for PRM'ing. That didn't happen and TfW had to PRM the units with the help of some Porterbrook loan 153s.

I was under the impression the 769s were an interim provision for TfW but am not sure how they intend to use all nine, particularly as it is only Rhymney conductors who currently sign them.

Lets hope the actually deliver reliability for TfW and prove the concept.

The TfW 769s are supposed to be temporary. They'll be withdrawn once the Stadler Flirts are up and running on the Rhymney line, so it's unlikely the 769s will be in use by TfW for more than 3 years from now. Of course plans could change and the 769s could be deployed elsewhere in S Wales if they finally prove to be reliable but TfW has an entire fleet replacement on order, so there'll be no need for the 769s to hang around once the Rhymney line is electrified and the Flirts are running.

 

[Bob Price]

5Z53 is not a diagram Bob, but a Train identification. A diagram is the pre-planned full days work for a unit. There is one out in service and another out training.

I am looking at a Diagram of Cardiff and the Valleys, as in a map showing the workings. There are a few 5Zxx workings on there. Just wondered if they are 769's testing alongside the operating train. Be interesting to have three units out.

 

[Bikeman78]

There must have been a reason for the extra order for the 769's. Perhaps the plan was Rhymney to Penarth would be 100% 769's?

== Doublepost prevention - post automatically merged: 17 Nov 2020 ==

Notice 5Z53 also on the diagrams. Are they running one and testing another?

769002 is back out on the same diagram again today. I saw it at Queen Street. Pre Covid there were nine sets required for Penarth-Bargoed/Rhymney. The December 2020 timetable will require six sets of stock.

 

[PHILIPE]

I am looking at a Diagram of Cardiff and the Valleys, as in a map showing the workings. There are a few 5Zxx workings on there. Just wondered if they are 769's testing alongside the operating train. Be interesting to have three units out.

769003 is out training today. I presume these runs will continue until training complete

 

[Bikeman78]

I've noticed a reduction to 3 Cars on most of the Rhymney Valley lately, the Caerphilly Bay shuttle and some Rhymney Bridgends running as Pacer + 1 x 153 and one circuit as 3 x 153s

As you say, most are Pacer+153 today. I travelled on one such pair to Caerphilly. Definitely more power than the 769. Similar weather to yesterday, they peaked at 43/38 mph from Heath to Llanishen to Lisvane compared with 33/30 on the 769. Also noticable how slowly the 153s pull away. The 142 revved up straight away and sat there slogging its guts out waiting for the slow brakes on the 153 to release.