Class 175s to GWR

[REVUpminster]

IIRC the number is dependent to the number of cabs in the formation.

Would that apply to empty stock moves?

 

[Rhydgaled]

the 175s are good trains but my only issue with them when they were in Wales was capacity. Back in the days of the 175s between Cardiff and Swansea I would avoid the 175s because I could never get a seat on one and would frequently end up standing

Agreed; 2 or 3 coaches is simply not enough capacity for services between Cardiff and Swansea, except perhaps Swanline stoppers if passengers avoid them for the faster services, and the Wales & Borders franchise never had access to enough suitable stock to allow the 175s to run in pairs everywhere that would have made sense.

 

[craigybagel]

IIRC the number is dependent to the number of cabs in the formation.

Would that apply to empty stock moves?

On Sprinters the maximum (10 cabs) is set at that level because of fears that with any more cabs, the voltage drop too low. Obviously in this case it made no difference if it was in service or ECS.

It's been a while since I did my 175 training, but if I remember rightly it was 12 cars max - again regardless of whether or not it was in service. I suspect the issue here would be the limit the TMS can cope with, but I'm open to correction. Even running 2 units in multiple was rare enough, and the longest I've ever driven was a 7 car (on a very disrupted day).

 

[43096]

On Sprinters the maximum (10 cabs) is set at that level because of fears that with any more cabs, the voltage drop too low. Obviously in this case it made no difference if it was in service or ECS.

Are 175s 110V electrically? If so, voltage drop wouldn't be a major factor.

 

[driverd]

Are 175s 110V electrically? If so, voltage drop wouldn't be a major factor.

As 24v is a relatively universal standard for DMUs (up to brand new CAF Civity), I'd be surprised if it was anything other than 24v.

 

[D365]

As 24v is a relatively universal standard for DMUs (up to brand new CAF Civity), I'd be surprised if it was anything other than 24v.

Other than Class 22x and, as I recently learned, Class 185!

My electrical schematics suggest the Class 175 and Class 180 use 110V DC for the control voltage, but I don't personally have any working experience with Alstom (ex Met-Cam) rolling stock.

 

[driverd]

Other than Class 22x and, as I recently learned, Class 185!

My electrical schematics suggest the Class 175 and Class 180 use 110V DC for the control voltage, but I don't personally have any working experience with Alstom (ex Met-Cam) rolling stock.

Well, you live and you learn! The 22x makes sense as a quasi-emu, but the 185 surprises me!

I should really stop speculating and hand over to the people who know.

 

[Ashley Hill]

On Sprinters the maximum (10 cabs) is set at that level because of fears that with any more cabs, the voltage drop too low. Obviously in this case it made no difference if it was in service or ECS.

And Pacers were 8 cabs.

 

[FGW_DID]

Would that apply to empty stock moves?

Yes it does. Even when just moving units around the depot we adhere to 12 vehicles max and that would normally be 4x 3 cars. 6x 2 cars would be very unlikely .

 

[s491]

Other than Class 22x and, as I recently learned, Class 185!

My electrical schematics suggest the Class 175 and Class 180 use 110V DC for the control voltage, but I don't personally have any working experience with Alstom (ex Met-Cam) rolling stock.

I know 180's manage to use 24V (engine start), 110V (control) and 415 3 phase (HVAC) which is quite an achievement.

 

[Mike Machin]

I’m not a particularly knowledgeable expert enthusiast, just a traveler with passing interest in the railways. I was wondering if someone with more knowledge than me could confirm if the introduction of Class 175s onto GWR services is allowing more Class 158s to be available for Cardiff/Bristol to Portsmouth service?

On all of my recent journeys the train has been formed of a couple of 158s, as have the trains we have passed going in the other direction. So much nicer than the austere discomfort of the 165/166 units I have suffered in the past.

Have I just been lucky?

Back to the main topic of this thread and I have to say although I have never travelled on a 175, they do look rather nice!

 

[fgwrich]

I know 180's manage to use 24V (engine start), 110V (control) and 415 3 phase (HVAC) which is quite an achievement.

Very Mk3 like!

 

[REVUpminster]

I’m not a particularly knowledgeable expert enthusiast, just a traveler with passing interest in the railways. I was wondering if someone with more knowledge than me could confirm if the introduction of Class 175s onto GWR services is allowing more Class 158s to be available for Cardiff/Bristol to Portsmouth service?

On all of my recent journeys the train has been formed of a couple of 158s, as have the trains we have passed going in the other direction. So much nicer than the austere discomfort of the 165/166 units I have suffered in the past.

Have I just been lucky?

Back to the main topic of this thread and I have to say although I have never travelled on a 175, they do look rather nice!

The three 158s used at Exeter should be returning to Bristol when enough 175s arrive which looks like the new year now; as removing HSTs are the priority.

 

[Snow1964]

I’m not a particularly knowledgeable expert enthusiast, just a traveler with passing interest in the railways. I was wondering if someone with more knowledge than me could confirm if the introduction of Class 175s onto GWR services is allowing more Class 158s to be available for Cardiff/Bristol to Portsmouth service?

On all of my recent journeys the train has been formed of a couple of 158s, as have the trains we have passed going in the other direction. So much nicer than the austere discomfort of the 165/166 units I have suffered in the past.

It is looking like 175s will not release 158s from Exeter area until sometime in Spring or Summer 2026 at the earliest.

You were lucky if you got 4car 158s on Cardiff-Portsmouth
Today, the 8 diagrams are :
1 train 2car 158
3 trains 4car 158
4 trains 3car 166

But should be noted the 175s wont release enough 158s to allow all Portsmouth-Cardiff trains to become 5car 158 (as GWR simply doesn't have enough 158s)

It also remains to be seen if the 175s allow the former outer suburban 166s to be concentrated longer services from Bristol (to Weymouth, Worcester etc), or if they will continue to randomly mix with 165s (which were never configured for longer journey passenger comfort, being inner suburban and local trains)

 

[s491]

Very Mk3 like!

Mk'3 make do with batteries (110V) and 415V (3 phase) rather than yet another power source.

 

[fgwrich]

Mk'3 make do with batteries (110V) and 415V (3 phase) rather than yet another power source.

Oh I know, I still occasionally work with them. But the principles are similar and you just have a 750HP Cummins lump creating the power source than a RP200 of the time.

I wonder if that was done as part of the design request from First Group (to make maintenance easier at somewhere like OOC) or something Alstom was offering at the time?

 

[Snow1964]

Been announced that a contract for upgrades at Laira depot for 175s has been awarded to Emeg value £3,159,166

1 buyer​

• First Greater Western Wiltshire

1 supplier​

• Emeg Group Chesterfield

Description​

GWR Laira Depot Enhancements Works Location: Laira Depot is a Traction and Rolling Stock depot situated in Plymouth, Devon. The depot is Network Rail owned and leased as a Traction and Rolling Stock Depot (T&RSD) to Great Western Railway as a primary location in the Southwest of England for the maintenance, repair, servicing and cleaning of high speed rolling stock including GWR AT300, Class 175 trains and GWR operated DMU fleets. Project Background Laira Train Depot is owned by Network Rail (NR) and leased by Great Western Railway (GWR) as the Train Operating Company (TOC). As part of the need to increase passenger capacity and provide additional rolling stock to replace the aging High Speed Train (HST) fleet to the South-West, GWR have identified a need to increase the operational capacity of the Laira Traction and Rolling Stock Depot (T&RSD). GWR have entered a new rolling stock contract to supply Class 175 Trains, these Trains will be maintained at Laira T&RSD.

Award Detail​

1	Emeg Group (Chesterfield) Laira Depot Enabling works: Class 175 Reference: 1 Value: £3,159,166

https://bidstats.uk/tenders/2025/W47/859046297

 

[XFeed]

And of course TfW staff did servicing and light maintenance on them until recently at Canton.

Canton only carried out very light maintenance and running repairs for units to be able to return to Chester.

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With 27 units coming and looking like they’re not to across too many routes, it should be pretty good once it’s all up and running!

Probably 26 units with 008 being unavailable for the foreseeable future, if ever ?

 

[northernbelle]

Canton only carried out very light maintenance and running repairs for units to be able to return to Chester.

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Probably 26 units with 008 being unavailable for the foreseeable future, if ever ?

Yes, 26 units. The left over vehicles are nothing to do with GWR.

 

[Bob85]

Have any units been repainted / re-vinyled into GWR livert yet?

 

[Pete_uk]

Been announced that a contract for upgrades at Laira depot for 175s has been awarded to Emeg value £3,159,166

https://bidstats.uk/tenders/2025/W47/859046297

That's a very specific number!

 

[REVUpminster]

That's a very specific number!

And will not pay for much. Maybe the lifting road and bogie exchange at Exeter might actually get used. Do they ever use it?

 

[BillStampy]

Realtime Trains | 5V84 1022 Wolverton Centre Sidings to Laira T.& R.S.M.D. | 28/11/2025

Real-time train running information for 5V84 1022 departure from Wolverton Centre Sidings to Laira T.& R.S.M.D. on 28/11/2025. From Realtime Trains, an independent source of train running info for Great Britain.

www.realtimetrains.co.uk

Another move from Wolverton for this Friday.

 

[XFeed]

Yget need to endure the under frames are regularly cleaned ( avoiding a couple of ‘sensitive’ areas like the purpose built and programmed underframe wash at Chester did.

Underframes were washed prior to each exam, weather conditions/wash operational. You are correct that the underframe wash was programmed to avoid certain areas plus the wash pressure was also reduced in an attempt to avoid earth faults during cleaning.

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To be fair Alstom usually managed to deliver the contracted 23 in service each day under TFW. If maintained properly, they are fairly reliable trains.

£1500 fine per unit per day below the contracted 24/27

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As

Is Class 175 engineers being recruited by GWR not enough?

As far as I`m aware no ex Alstom Chester 175 maintenance staff have moved to GWR.

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I suppose it'll be down to the condition TfW have left them in. It didn't sound like they treated them very nicely in their twilight years in Wales.

All maintenance schedules as per VMI were carried out as required to each unit prior to the units being withdrawn from traffic.

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I think it's all to do with the decision to bin chester depot off to CAF and put all the new 197's there. As such there was just no space to continue maintenance of the 175's at Chester. That's without even getting into the poor job CAF did with regards to 175 maintenance and currently even 197 maintenance.

Overall correct

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Technically the 175 fleet was never maintained by ATW, or latterly by TFW either. Alstom maintained the sets in the purpose-built facility at Chester and provided the agreed number of operational units each day. This was the depot that was sold to CAF who proceeded to make a pig’s ear of matters resulting in the 175 fleet being withdrawn prematurely.

Mostly correct apart from Network Rail owns Chester depot.

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The pair running to Ely Papworth sidings for storage today has sat down between Peterborough and Ely, several hours delay.

Does anyone know the reason that the units came to a stand ?

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I already have the popcorn on standby. 175101 has never worked very well since the most recent reform. It has vehicles from three different units.

I`m not sure of 101 but as a side note at the time of withdrawal either 104 or 109 did not have any of its original cars within the units, any different configurations were known as hybrids and there was a small number of units classed as hybrid for various reasons.

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The 175s will not of course couple to any other type currently in the GWR fleet. I say "currently" as I understand they will couple to a 180.

Correct

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I very much like the 175s, but they have never reliably run in double formation.
A good day is when a 3-car turns up rather than a 2-car.
FNW, ATW and TfW all wanted 4/5/6-car operation but never got it reliably.
The fleet availability was also too low for multiple working to be other than a luxury, except where it was essential so that trains could split en route.

I disagree that 175s could not run reliably coupled together

 

[XFeed]

Yes, full guard release. As built they were set up for driver release, and the intermediate panels only had close buttons, but the wiring has been removed from the drivers release buttons, and release buttons have been added to the intermediate panels (in addition to the full panels on the cab bulkhead).

Incorrect regarding that the wiring had been removed from the drivers cab door release/arming buttons for A or B sides.

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I would guess so - the damage to 008 was reported as quite extensive.

Correct and not for the first time !

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You're assuming they haven't harmonised the exam schedules between the misformed units. It's perfectly normal to do so when the new formation is planned to be long-term/permanent.

When different 175 cars were swapped around into other units the additional car was "harmonised" as you say to reflect the current units exam status.

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The beauty of the 175 is it can run in 2, 3, 4, 5, 6 formations. The only restricting factor is platform lengths on Okehampton and Barnstaple services, but there is probably a way round it with selective door closures.

The maximum length 175s were run was 9 cars

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How many 175's (units or vehicles) can be operated together in multiple?

A maximum of 9 cars was ever used

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I know 180's manage to use 24V (engine start), 110V (control) and 415 3 phase (HVAC) which is quite an achievement.

All the mentioned 180 voltages also apply to 175 including additional 3 phase for air compressor and battery chargers along with single phase for toilet handrier and at seat 3 pin sockets plus 24v also used for Voith transmission control.

 

[craigybagel]

Incorrect regarding that the wiring had been removed from the drivers cab door release/arming buttons for A or B sides.

The wiring may not have been removed, but some steps were taken to stop those buttons working. Only the close button worked

The maximum length 175s were run was 9 cars

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A maximum of 9 cars was ever used

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But longer were permitted in theory.

 

[Mike Machin]

It is looking like 175s will not release 158s from Exeter area until sometime in Spring or Summer 2026 at the earliest.

You were lucky if you got 4car 158s on Cardiff-Portsmouth
Today, the 8 diagrams are :
1 train 2car 158
3 trains 4car 158
4 trains 3car 166

But should be noted the 175s wont release enough 158s to allow all Portsmouth-Cardiff trains to become 5car 158 (as GWR simply doesn't have enough 158s)

It also remains to be seen if the 175s allow the former outer suburban 166s to be concentrated longer services from Bristol (to Weymouth, Worcester etc), or if they will continue to randomly mix with 165s (which were never configured for longer journey passenger comfort, being inner suburban and local trains)

Thank you very much for such a detailed reply! I guess I have just been lucky on recent trips, but I’m sure it’s a difficult route to determine what the best stock for this service should be. The trains make fairly frequent stops and at peak times it’s not unusual for people to literally travel five minutes between two stations - I have witnessed piling on at Fratton for example, only for most of them to get off at Cosham or Fareham.

Equally I have seen plenty of people boarding at Southampton Central and travel all the way to Bristol or Cardiff, so it has to somehow satisfy short-hop local commuters and the longer-distance Inter-City traveller. Something like TPE’s Class 185 would perhaps be ideal - wishful thinking of course!

 

[Wyrleybart]

Been announced that a contract for upgrades at Laira depot for 175s has been awarded to Emeg value £3,159,166

https://bidstats.uk/tenders/2025/W47/859046297

So when did the first 175 rock up at Laira, and how long before that did the DfT plan as opposed to authorise the replacement of "Castles" with the 175s ?

This is the typical DfT playbook, with piecemeal and poorly timed arrangements o the railway industry. It was always known that that 2+4 GTIs would be a temporary arrangement and would be an expensive proposition, and the IETs would likely be an expensive addition to the fleet. Obviously ministerial intransigence over electrification has seen much more diesel use of the MTUs which has stretched the fleet, but overall the local GWR services need DMUs and there just aren't enough.

The DfT knew the 175s were redundant from TfW when the 197s were ordered, first class 197 delivered to Crewe in April 2021 and first one entered service November 2022. Chester depot which was home to the 175s was transferred to become a CAF depot for the 197s in June 2022 (3.5 years ago) so the writing was very clearly "on the wall" for the class 175. So perhaps it is reasonable to ask why it has taken so long for DfT to make the decisions / plan for the future of the West fleet, and this doesn't take into account the splitting of the Cardiff-Penzance route at Exeter for the foreseeable future, purely for the benefit of getting the "new" trains into service - crews maintenance etc.

Be interesting to see how long it takes to get Exeter and eventually other depots on board with the fleet of 26 class 175s. Will they be tyre turned t Laira ?

 

[tfw756rider]

So when did the first 175 rock up at Laira?

On the 27/11/24.

(Yes, a year ago tomorrow).

 

[BillStampy]

On the 27/11/24.

(Yes, a year ago tomorrow).

Certainly doesn't feel like a year. Read this and had to double check it for myself!