Class 701 'Aventra' trains for South Western Railway: progress updates

[nctd2306]

701010 seems to be a bit of a rogue unit. Only eleven days in service since its first one a month ago. Three others have entered service more recentkly and racjked up twice as many days in service.

It broke down on Monday and hasn't been out since. I don't know what the issue was with it but it caused my train to be cancelled which was frustrating!

 

[norbitonflyer]

It broke down on Monday and hasn't been out since. I don't know what the issue was with it but it caused my train to be cancelled which was frustrating!

It was also hors de combat for nearly two weeks from Christmas Eve until 4th January inclusive.

 

[WWTownEnth]

Any news on further units coming into passenger service?

 

[Bigfoot]

Any news on further units coming into passenger service?

There won't be any significant number for a good few weeks. 701/5 car trials start late spring. There's just enough 10s for the current timetable. Some more spares might be helpful to cover for failures but diagram wise we won't see changes for some time, probably May.

 

[WWTownEnth]

There won't be any significant number for a good few weeks. 701/5 car trials start late spring. There's just enough 10s for the current timetable. Some more spares might be helpful to cover for failures but diagram wise we won't see changes for some time, probably May.

may? Wow. That is a long wait. Why so long?

 

[Goldfish62]

There won't be any significant number for a good few weeks. 701/5 car trials start late spring. There's just enough 10s for the current timetable. Some more spares might be helpful to cover for failures but diagram wise we won't see changes for some time, probably May.

Given that SWR are claiming 45 units by "summer" there'll clearly then have to be a bit of a rush from May onwards then.

Wonder what's going to cover the 458/5s which I'm told are coming off in March.

 

[TEW]

The 701 diagrams are due to start increasing again from February. Should be back to a pretty consistent increase in diagrams from then.

 

[WWTownEnth]

Quite conflicting information in the above few posts……

 

[Covshire1]

701022 has worked 5Q52 Wimbledon Park Depot Sdgs to Clapham Yard Sidings this evening. It's first move since it left Marchwood on 23/12/25.

 

[Robert Carroll]

Given that SWR are claiming 45 units by "summer" there'll clearly then have to be a bit of a rush from May onwards then.

Wonder what's going to cover the 458/5s which I'm told are coming off in March.

But "summer" might mean 31 August.

 

[southerngtr]

Not really. Until two weeks ago there were 6, 7, 8, 23, 45 & 49 at Long Marston. So Four lower numbered ones and only two higher numbered ones. Particularly half of them in the first ten.

I expect 701003 at Derby might be the last !.

But the 701s have varying histories. The first ten (or more ?) had to go back to Derby for enlarged cabs. Once SWR realised their ideas were not going to be accepted by the people who have to work in the cab. Some other factors will be ones that were accepted first and then moved into store. Quite a few 701s seem to have been moved on and back off SWR - I am not 100% as I was not following the 701 introduction very closely until early 2025.

A general point about new fleets. They rarely get introduced in numerical order. Some get held back by faults. Early examples get sidelined for more detailed type testing so might not have seats etc in (usually the first one or two). Some fleets have a redesign after the first few are seen in the flesh and so get left behind if the manufacturer does not want to disrupt ongoing production.

Do we know about the specifics to the cab enlargement ? And have all units had this enlargement ?

 

[43096]

But "summer" might mean 31 August.

Informed Sources Third Law applies: “Always mistrust schedules based on the seasons”

 

[WWTownEnth]

There won't be any significant number for a good few weeks. 701/5 car trials start late spring. There's just enough 10s for the current timetable. Some more spares might be helpful to cover for failures but diagram wise we won't see changes for some time, probably May.

The 701 diagrams are due to start increasing again from February. Should be back to a pretty consistent increase in diagrams from then.

So which of these statements is correct? Because I don’t think they both can be….

 

[swr444]

So which of these statements is correct? Because I don’t think they both can be….

I think I’d go with TEW, who seems to have the most info when it comes to new diagrams

 

[class701]

We are stilll getting 455s on the Dorking via Epsom line so there clearly aren't any spare 701s around yet. The last 455 tours clearly weren't.

 

[WWTownEnth]

I think I’d go with TEW, who seems to have the most info when it comes to new diagrams

Thanks. Makes sense although given both are known for considered and helpful contributions it would be good to understand the reason for the deviation in views.

 

[Bigfoot]

Thanks. Makes sense although given both are known for considered and helpful contributions it would be good to understand the reason for the deviation in views.

My source is a member of the 701 training team. It might only be partly true, we will wait and see.

I'm fairly certain that we will not see a diagram a week like in the past. There are still issues having enough crew trained to drive them at current level of usage.

Many (not all) who drive them already are a little fed up of being asked to swap their duty so the 701 work can be covered.

 

[Snow1964]

My source is a member of the 701 training team. It might only be partly true, we will wait and see.

I'm fairly certain that we will not see a diagram a week like in the past. There are still issues having enough crew trained to drive them at current level of usage.

Many (not all) who drive them already are a little fed up of being asked to swap their duty so the 701 work can be covered.

Many thanks, I think that explains the difference, you are basing it on driver knowledge and rostering, and TEW is almost certainly referring to physical units certified for service.

So looking like extra unit every 8-10 days (3-4 per month from February) which obviously means 455s held for substitution can be dropped, and no one will need to retain 455 competency.

But at same time there is not yet universal driver knowledge on 701s so some are still restricted to 450 and 458 workings. Only when 100% of suburban drivers are passed can roster diagrams be unsegregated.

 

[adc82140]

We are assuming that the short notice 455 substitutions are due to unavailability of a unit, but are any of them actually down to unavailability of a driver who signs 701s?

 

[pompeyfan]

We are assuming that the short notice 455 substitutions are due to unavailability of a unit, but are any of them actually down to unavailability of a driver who signs 701s?

No, it’s purely down to unit availability if it’s an all day diagram. It’s a huge amount of effort to substitute the unit for the whole diagram if only one or two trips are uncovered due to lack of traction knowledge as several depots have now lost their 455 knowledge.

 

[TEW]

There's another 5 LTP 701 diagrams from the 9th February. I don't think any will be 701 from that date but will start going over from mid/late February. There does seem to have been a slowdown in new units being accepted for passenger service though so plans may have changed and it may have moved back slightly.

 

[Peter Sarf]

Do we know about the specifics to the cab enlargement ? And have all units had this enlargement ?

It certainly was not all 701s in the build that started off with a smaller different drivers desk in the cab. If I remember correctly the need to change the design came about part way through the build of the 701/0s. At a very rough guess within twenty of the first 701/0s built. I am fairly certain the alteration was to move the cab bulkhead back into the coach. That is the wall separating the cab from the passenger compartment. Might sound fairly simple but I expect all sorts of electrical equipment would have also needed moving and that would have resulted in wiring looms not fitting and so needing altering.

No, it’s purely down to unit availability if it’s an all day diagram. It’s a huge amount of effort to substitute the unit for the whole diagram if only one or two trips are uncovered due to lack of traction knowledge as several depots have now lost their 455 knowledge.

I wonder if there are any drivers who can drive 455s that are not yet qualified to drive 701s ?.
(I assume none).

I also wonder if there are any drivers who can drive 450s/458s that are not yet qualified to drive 701s ?.
(I assume drivers based a long way out of London or who only work those longer routes will never need to learn 701s).
(I am thinking about the proportion of outer suburban drivers not yet qualified on 701s).

It is obvious from further up thread that nigh on 100% availability is required out of the 701s currently.

My take on comments above is that over the next month or so enough 701s will be accepted to allow 455s to no longer be needed as cover.
Then, beyond that, as more 701s get accepted training might well become the bottleneck. I remember back last year there was a point where a whole days diagram could not be crewed reliably so the number of 701s accepted rose faster than the number of 701s in use. I suppose we might soon be seeing the same issue effect another group of routes (outer suburban).

EDIT 28/01/2026
It seems cab enlargement has become an urban myth - just drivers desk re-designed.

 

[Big Jumby 74]

I would imagine the outer area depots who will sign 701's will be Woking, Guildford, and (one link?) at Farnham?

 

[Peter Sarf]

I would imagine the outer area depots who will sign 701's will be Woking, Guildford, and (one link?) at Farnham?

Thanks. That could be where the next bottle neck appears (crew training wise).

It is not a criticism of SWR btw as these things always have to go in fits and starts. For a given area/service-group need a lot more crew trained on 701s before it is possible to switch over a whole diagram. But training crew takes them of revenue earning work and also training them too early just lets their qualification lapse.

 

[Bigfoot]

The Feb PA brings diagrams, but more than likely to be STP to other stock. The Feb PA usually takes the timetable through until the May timetable change.

 

[Big Jumby 74]

For a given area/service-group need a lot more crew trained on 701s before it is possible to switch over a whole diagram. But training crew takes them of revenue earning work and also training them too early just lets their qualification lapse.

Exactly so. The one fly in the (all suburban trains) 701 thinking that has crossed my mind, is the need for main line diversionary route knowledge for weekend engineering work, primarily via Chertsey. Basing depot has always played a large part in this, as the likes of Woking/Waterloo etc would not be able to cover everything on top of their own work.
Thus far a couple of Weybridge return trips have been covered by 450's worked by Basing for this very purpose.

To my mind it's completely unpracticable to train xx bodies at Basing on 701's (this is when someone with closer hands on tells me they are.. !) both in cost terms and in traction knowledge retention, unless there is a plan to 'pass' crews between, Basing and (eg) Woking to give them a greater degree of 701 work.

Otherwise with 450's still visiting Clapham Yard between the peaks (off main line work) it may be that some of these be used for a couple of return trips to Weybridge via Chertsey, for the benefit of Basing depot's retention of route knowledge?

 

[meld3]

As its been half a lifetime since the 701's were ordered....what was the original plan for the 10-car and 5-car 701s to work ?
There are an awful lot of both still to enter service, whilst nearly all the 455/456's have gone, so what is next to be replaced ?

 

[Stephen42]

We are assuming that the short notice 455 substitutions are due to unavailability of a unit, but are any of them actually down to unavailability of a driver who signs 701s?

In addition to the above, when the 455s are allocated at start of day it's a very consistent set of diagrams. The diagram starting 5J97 is usually 450s, when 455s are used it's the one to switch over with 5M03 running with 450s instead. It looks much more keeping 455s on diagrams that will be worked by crews who still sign 455s.

I wonder if there are any drivers who can drive 455s that are not yet qualified to drive 701s ?.
(I assume none).

I'd expect some. Guildford had 455s stabled until the end of last month and doubt 701 training is 100% complete there. Don't know if they had 455s immediately removed from their cards or not though.

I also wonder if there are any drivers who can drive 450s/458s that are not yet qualified to drive 701s ?.
(I assume drivers based a long way out of London or who only work those longer routes will never need to learn 701s).
(I am thinking about the proportion of outer suburban drivers not yet qualified on 701s).

That's probably a larger category. Training is ongoing and existing drivers doing that training will sign 450s at least.

It is obvious from further up thread that nigh on 100% availability is required out of the 701s currently.

A mere 94% with 34 out of 36 required. That can be doable with larger fleets. The 701s haven't fully settled in yet and two isn't a lot to play with, one in planned maintenance and two faults in quick succession is enough to cause a shortfall.

My take on comments above is that over the next month or so enough 701s will be accepted to allow 455s to no longer be needed as cover.
Then, beyond that, as more 701s get accepted training might well become the bottleneck. I remember back last year there was a point where a whole days diagram could not be crewed reliably so the number of 701s accepted rose faster than the number of 701s in use. I suppose we might soon be seeing the same issue effect another group of routes (outer suburban).

Training will be continuing in this period while no new diagrams are being added. Swaps being required is pretty common; hypothetically if 10% of work needs training but only 25% have completed training those people will spend 40% of their time doing that work or four times the usual rate. Particularly for outer depots where the 701 trained will do more inner work and feel it's taking them off the faster work people might be unhappy even if the work can be reliably covered through those swaps.

The number of people going through the training and the pass rate will give reliable projections for staff trained. Units being commissioned is less predictable, faults might be found when they start doing test runs.

Otherwise with 450's still visiting Clapham Yard between the peaks (off main line work) it may be that some of these be used for a couple of return trips to Weybridge via Chertsey, for the benefit of Basing depot's retention of route knowledge?

There are four 450 empty workings for this purpose that run weekdays (from splits at London Waterloo)

5C91 1028 LONDON WATERLOO - WOKING 1134
5S92 1141 WOKING - LONDON WATERLOO 1334

5S93 1925 LONDON WATERLOO - WOKING 2029
5C94 2047 WOKING - LONDON WATERLOO 2151

 

[Meglos]

As its been half a lifetime since the 701's were ordered....what was the original plan for the 10-car and 5-car 701s to work ?
There are an awful lot of both still to enter service, whilst nearly all the 455/456's have gone, so what is next to be replaced ?

Remember the 701's were ordered pre-Covid when there was a more expansive timetable. Such as an WAT-EPS-DRG/GLD every 15 minutes, rather than every 30 minutes, that alone accounts for an additional 6 units. You probably needed an extra 6 units to provide for a full WAT-Hounslow-WAT timetable.

Then there are well over a dozen diagrams covered by 450's & 458's. These will gradually get replaced by 701's. Likely with some of the 450's moved to mainline services.

Assuming the December 2025 timetable includes re-instatement of a lot of the services lost during Covid, plus the replacements of the 450/458 diagrams that will account for at least another 24 units. That is when the 701/5's may start to be needed.

 

[DavidRail]

No extra units would be required for Hounslow Loop, as the service runs in peak hours. What would be needed for all day service, is more drivers.