Chiltern MK5s Starting 2026 (non speculative updates thread)

[DelW]

I assume the Mk5 sleepers can be reformed at will as they split and reform en-route on the Highland sleeper, so how come we went backwards for the TPE stock.

AIUI they can't, the sleeper coaches have to be kept in fixed sets as different coaches within each set have different equipment fitted to them. Sets can only be combined or separated at discrete positions for the services north of Edinburgh.

 

[JonathanH]

AIUI they can't, the sleeper coaches have to be kept in fixed sets as different coaches within each set have different equipment fitted to them. Sets can only be combined or separated at discrete positions for the services north of Edinburgh.

One coach is lopped out of each 'set' during the winter such that they run with 7 / 14 coaches instead of 8/16.

The thing with the Mark 5 coaches going to Chiltern is that there are effectively four different types of coach in each five coach formation and two of the five only have gangways at one end.

The fascination with locomotive hauled coaching sets which can have numbers of coaches differing at whim depending on the weather, demand, or whatever is always a bit strange. Chiltern's DMU fleet allows them to form any length of train between 2 and 9 coaches without any need for complex shunting. Elsewhere, Intercity operators have the ability to run 5, 9 and 10 coach trains to suit demand, (and admittedly don't always get it absolutely right) and everyone thinks all the trains should be standardised on 9 coaches, regardless of demand. Even if LHCS did operate with flexible formations, there are still a number of different types of coaches which have to be in the formation, and no doubt there would be criticism that sometimes the operators don't match formations to the demand.

 

[Pumbaa]

Not sure what all the concern about capacity is about. Chiltern appear to be withdrawing 25 - not particularly intensively used - passenger carrying vehicles and replacing them with 65. (Admittedly I thought they had more currently).

Evidently some moving parts we don’t know, but combined with internal industry declaration of a Dec 26 timetable uplift, clear this will set off a rolling stock cascade and associated train service changes to match.

Given the hoops TOCs have to go to get DfT/Treasury support to spend any money currently, I’d wager this will have been assured to the nth degree. Been an open secret for long enough.

 

[Bald Rick]

There is your issue - "short term Britain" where everything has to be considered in periods - generally five years, like the CPs or ahem parliaments etc. This country cannot cope with the thought of "for it's lifetime" and the shenanigans of the TPE franchise is a classic example , pretty hence why the Mk5s are where they are.

In this case, short to medium term has to be right though. The rest of Choltern’s fleet is likely to need replacement in the next decade, and that will most likely be some sort of battery hybrid, and if you are providing depot snd charging facilities for that for that then economy of scale will push you down the route of replacing the Mark 5s too.

 

[stevieinselby]

In this case, short to medium term has to be right though. The rest of Choltern’s fleet is likely to need replacement in the next decade, and that will most likely be some sort of battery hybrid, and if you are providing depot snd charging facilities for that for that then economy of scale will push you down the route of replacing the Mark 5s too.

While the Mk5As might not be amenable to being shuffled and reformed into different length rakes easily, they could be hooked up to a compatible electric or bi-mode loco as and when the line is partially or fully electrified without any modification to the carriages. Economies of scale may not suggest ditching rolling stock that is only 10–15 years old unless there is an alternative use for it elsewhere on the network.

 

[Bletchleyite]

While the Mk5As might not be amenable to being shuffled and reformed into different length rakes easily, they could be hooked up to a compatible electric or bi-mode loco as and when the line is partially or fully electrified without any modification to the carriages. Economies of scale may not suggest ditching rolling stock that is only 10–15 years old unless there is an alternative use for it elsewhere on the network.

Indeed that was what TPE intended to do with them.

 

[Wilts Wanderer]

The fascination with locomotive hauled coaching sets which can have numbers of coaches differing at whim depending on the weather, demand, or whatever is always a bit strange. Chiltern's DMU fleet allows them to form any length of train between 2 and 9 coaches without any need for complex shunting. Elsewhere, Intercity operators have the ability to run 5, 9 and 10 coach trains to suit demand, (and admittedly don't always get it absolutely right) and everyone thinks all the trains should be standardised on 9 coaches, regardless of demand. Even if LHCS did operate with flexible formations, there are still a number of different types of coaches which have to be in the formation, and no doubt there would be criticism that sometimes the operators don't match formations to the demand.

Whilst I agree with your point about flexibility, that’s a lot of redundant cabs being carried around in multi-formations and (Chiltern being a good example) tends to result in train formations that you can’t walk through, which isn’t ideal for an intercity route and can end up needing more traincrew - 80x also being a case in point.

I used to work for an operator where it wasn’t unusual for traincrew to lock the rear unit of 3 out of use, even when specially-provided for major crowds on special events etc, due to the lack of inter-unit gangways. Modern standards tend to require a competent member of staff in every non-gangwayed portion of a train these days.

 

[43096]

Modern standards tend to require a competent member of staff in every non-gangwayed portion of a train these days.

Modern standards, or because no one is prepared to address the elephant in the room - too many stupid agreements that are not being challenged and removed.

 

[Bald Rick]

Modern standards tend to require a competent member of staff in every non-gangwayed portion of a train these days.

Standards do not require that.

Union agreements might, but that is very different.

 

[Bletchleyite]

Whilst I agree with your point about flexibility, that’s a lot of redundant cabs being carried around in multi-formations and (Chiltern being a good example) tends to result in train formations that you can’t walk through, which isn’t ideal for an intercity route and can end up needing more traincrew - 80x also being a case in point.

1. Chiltern is not an intercity operator. It operates commuter and regional/regional express services.
2. Chiltern does not require a member of staff in every portion. It operates DOO and most trains have a portion with no staff in it, some have more than one.

 

[800001]

1. Chiltern is not an intercity operator. It operates commuter and regional/regional express services.
2. Chiltern does not require a member of staff in every portion. It operates DOO and most trains have a portion with no staff in it, some have more than one.

DOO only as far as Banbury I believe?

 

[Bletchleyite]

DOO only as far as Banbury I believe?

Correct, but I'd reckon well over 50% of services out of Marylebone operate with at least one portion without staff in it, even if it may get one on arrival at Banbury.

 

[800001]

Correct, but I'd reckon well over 50% of services out of Marylebone operate with at least one portion without staff in it, even if it may get one on arrival at Banbury.

Didn't know they operated with them out of London, I always assumed they only joined at Banbury

 

[Bletchleyite]

Didn't know they operated with them out of London, I always assumed they only joined at Banbury

On DMUs they do, yes. So there is a portion of most trains (other than Mk3s) that operates between Marylebone and Banbury with no staff in it.

The Mk3s carry guards throughout.

 

[800001]

On DMUs they do, yes. So there is a portion of most trains (other than Mk3s) that operates between Marylebone and Banbury with no staff in it.

The Mk3s carry guards throughout.

Thanks for clarifying

 

[Energy]

Not sure what all the concern about capacity is about. Chiltern appear to be withdrawing 25 - not particularly intensively used - passenger carrying vehicles and replacing them with 65. (Admittedly I thought they had more currently).

More vehicles but less flexibility. With the class 168s, Chiltern can form them into 2 to 8 car sets, depending on the capacity needed. The Mk5As are fixed in length.

On Wembley match days, Chiltern shifts around maintenance to increase train lengths and subsequently increase capacity. With the Mk5As, the only way to increase capacity is to increase the service pattern.

While the Mk3s are leaving, I wouldn’t be surprised if some of the 165s will also be scrapped for parts

Fewer longer trains would be a much better operational and operating cost fit for the route.

Chiltern also has limited capacity at Marylebone, so it'll be interesting what services they add.

While the Mk5As might not be amenable to being shuffled and reformed into different length rakes easily, they could be hooked up to a compatible electric or bi-mode loco as and when the line is partially or fully electrified without any modification to the carriages. Economies of scale may not suggest ditching rolling stock that is only 10–15 years old unless there is an alternative use for it elsewhere on the network.

In this case, short to medium term has to be right though. The rest of Choltern’s fleet is likely to need replacement in the next decade, and that will most likely be some sort of battery hybrid, and if you are providing depot snd charging facilities for that for that then economy of scale will push you down the route of replacing the Mark 5s too.

Replied in speculative thread

 

[PLY2AYS]

On Wembley match days, Chiltern shifts around maintenance to increase train lengths and subsequently increase capacity. With the Mk5As, the only way to increase capacity is to increase the service pattern.

Chiltern do increase service capacity on event days, by running a greater service pattern with match day specials and event special services as well as special stop orders. You don’t need to always just put in more trains… but if you needed to add additional flexibility, it comes from 165 and 168 interchangeable sets.

It should be noted that not all special services go on to Birmingham.

While the Mk3s are leaving, it's expected that at least some of the 165s will also be scrapped.

Unsure where you’ve got this information from.

 

[Energy]

Chiltern do increase service capacity on event days, by running a greater service pattern with match day specials and event special services as well as special stop orders. You don’t need to always just put in more trains… but if you needed to add additional flexibility, it comes from 165 and 168 interchangeable sets.

Thanks for the information. It’ll be interesting how Mk5A and extra 168 services will cope, I’m yet to be convinced given the capacity downgrade compared to a double 168.

Unsure where you’ve got this information from.

It’s my speculation, edited to make it more clear.

I’d love for Chiltern to retain all stock but it seem unlikely to be that Oxford & Aylesbury (and the couple remaining Birminghams) will get the full 165 & 168 fleet.

 

[HeelBurton]

Assuming this is to do with the fact they’re a fixed formation set, and to reconfigure the SDO and electrickery would have been a faff.

Imagine the publicity if it had been tinkered with and made the sets less reliable than current rolling stock…

Agree with this 100%

I was part of one of the trainers in a different life when the 458’s were reformed from 4 car to 5 car. We had all sorts of niggling problems when the extra carriage was put in to do with electrics, what the TMS recognised and automatic selective door opening and some traction packages not doing what they should do.

better to leave it as it is to be sure

== Doublepost prevention - post automatically merged: 7 Aug 2025 ==

More vehicles but less flexibility. With the class 168s, Chiltern can form them into 2 to 8 car sets, depending on the capacity needed. The Mk5As are fixed in length.

On Wembley match days, Chiltern shifts around maintenance to increase train lengths and subsequently increase capacity. With the Mk5As, the only way to increase capacity is to increase the service pattern.

While the Mk3s are leaving, I wouldn’t be surprised if some of the 165s will also be scrapped for parts


Chiltern also has limited capacity at Marylebone, so it'll be interesting what services they add.



Replied in speculative thread

It is worth noting that when working Wembley events of busy services in general, a 2 car 165 although being slower fits way more passengers on than a 2 car 168 and thus will appear on sheets for driver liaisons at WCX during event days as HC (high capacity)

From a passenger view it’s an inconvenience when a 165 shows up but they are people movers and work horses. For this reason you’d probably want them to remain around as long as practical

 

[midland1]

1. Chiltern is not an intercity operator. It operates commuter and regional/regional express services.
2. Chiltern does not require a member of staff in every portion. It operates DOO and most trains have a portion with no staff in it, some have more than one.

Is not Birmingham to London an intercity operation.

 

[A S Leib]

Is not Birmingham to London an intercity operation.

It currently averages around 56 mph. I know they were faster pre-Covid, but that's still compared to 70 mph for Trent Valley stoppers or 51 mph for Euston – Birmingham via Northampton services.

 

[43102EMR]

It currently averages around 56 mph. I know they were faster pre-Covid, but that's still compared to 70 mph for Trent Valley stoppers or 51 mph for Euston – Birmingham via Northampton services.

Average speed doesn’t really determine it - it’s just not a higher speed service like most UK intercity services, but it’s very much an intercity service in it’s own right.

 

[Bletchleyite]

Is not Birmingham to London an intercity operation.

Average speed doesn’t really determine it - it’s just not a higher speed service like most UK intercity services, but it’s very much an intercity service in it’s own right.

It connects two cities, but so does the District Line. The InterCity service from Birmingham to London is operated by Avanti. Chiltern's service is a regional express/commuter operation near enough the same as WMT's service.

 

[Tetchytyke]

it’s very much an intercity service in it’s own right.

It really isn’t. It’s an outer-suburban service that happens to run between two cities. It’s the same as WMR/LNR.

 

[Rob F]

Probably a stupid question, but here goes!

If increased capacity was required for special events, could they be operated with 2 Mk5 sets with a loco in the middle? Probably platform lengths is an issue, but is it technically possible?

 

[Mikey C]

Standards do not require that.

Union agreements might, but that is very different.

Southeastern for example will regularly run 465-465-466 or 465-466-466 formations, with no gangway between the units, and DOO.

 

[KevL]

Ive just got one request..,can we have the mk3s n locos for TPE?!!!

 

[dooton]

Probably a stupid question, but here goes!

If increased capacity was required for special events, could they be operated with 2 Mk5 sets with a loco in the middle? Probably platform lengths is an issue, but is it technically possible?

Not technically possible as I understand it.

 

[Harpo]

Chiltern appear to be withdrawing 25 - not particularly intensively used - passenger carrying vehicles and replacing them with 65

Not an assumption I’d make. I can’t see DfT allowing a nett increase of that size.

My money says DfT will require a DMU cascade away from Chiltern to other TOCs (perhaps Turbos to FGW?) to allow 15x withdrawals. But that’s one for a speculative thread.

 

[Wyrleybart]

Probably a stupid question, but here goes!

If increased capacity was required for special events, could they be operated with 2 Mk5 sets with a loco in the middle? Probably platform lengths is an issue, but is it technically possible?

I am not very knowledgeable but I reckon there would be problems with that. AIUI the CAF stock was designed with a fairly basic (cheap) braking system - ie two pipe air brakes.

The WCML TDM system on AC locos and DVTs allowed for rolling stock either side of the loco, as there was a regularly afternoon train from Scotland which had motorail vans shunted onto the rear at Carlisle. The DVT and the class 90 had an E70 / DW3 brake valve in the cab which allowed the brake to be controlled a different way to normal; two pipe brakes

Not sure a Mk5 set could be configured with a loco between two sets apart from the potential for "jostling" by the loco in the middle. Ironically, when the first WCML drivers were learning DVTs I think there were a couple of formations of DVTs sandwiching AC electric locos.

== Doublepost prevention - post automatically merged: 7 Aug 2025 ==

Not an assumption I’d make. I can’t see DfT allowing a nett increase of that size.

My money says DfT will require a DMU cascade away from Chiltern to other TOCs (perhaps Turbos to FGW?) to allow 15x withdrawals. But that’s one for a speculative thread.

Maybe Harpo but the replacement of Mk5s on the "Mainline" services is initially for Mk3 withdrawal, but also for growth. I imagine there are quite a number of two car turbo diagrams which can be doubled up, or maybe 4 car 168s displaced from the "Mainline" dropping onto Oxford diagrams etc. I foresee a ripple down, but I guess it does depend on how much blood DfT want to suck out of the Chiltern rolling stock.
Also worth considering the relative age of the 165s and whether a few "christmas trees" might help the Rosco with fleet availabilty.