Class 397 125mph?

[The Planner]

I suspect the differential EPS speeds for Voyagers will have to go before a new general WCML speed profile can be introduced and signed, initially for Avanti's 80x due in 2023.
And that might only cover south of Preston/Crewe.
It all seems quite opaque at the moment, particularly the amount of track adjustment to achieve 125mph non-tilt without a saw-tooth profile.

All of which is quite advanced in the planning and delivery for south of Weaver as mentioned in other threads which is speed board changes only. The 221 differential will go and it will be saw tooth regardless as no one in considering track changes.

 

[LNW-GW Joint]

All of which is quite advanced in the planning and delivery for south of Weaver as mentioned in other threads which is speed board changes only. The 221 differential will go and it will be saw tooth regardless as no one in considering track changes.

Excellent.

 

[a_c_skinner]

I've never noticed a poor ride north of Newcastle (not done it since the 80x sets came in) and strongly suspect that running an 80x set on the WCML 221 speeds would not be noticed, certainly not commented upon, by "normal" passengers. It seems an obvious experiment.

 

[hexagon789]

All of which is quite advanced in the planning and delivery for south of Weaver as mentioned in other threads which is speed board changes only. The 221 differential will go and it will be saw tooth regardless as no one in considering track changes.

With decent enough acceleration even "sawtooth" adds up. Isn't the MML pretty sawtooth in profile and has been since the HSTs were first introduced but all those incremental changes have ox course over time brought the overall journey times down.

I've never noticed a poor ride north of Newcastle (not done it since the 80x sets came in) and strongly suspect that running an 80x set on the 221 speeds would not be noticed, certainly not commented upon, by "normal" passengers. It seems an obvious experiment.

Pretty much any journey running at full up to 125mph speeds is "lively" north of Newcastle in my view - irrespective of train.

Mk4s in particular curve rather interestingly!

 

[Bald Rick]

Exceptional cant deficiency rules apply on the ECML north of Newcastle, the MML (Bedford to Leicester, IIRC), and the Berks & Hants.

Similar levels of cant deficiency apply to many French ‘classique’ lines.

Were they to be applied to the WCML, then the ride would indeed become more ‘interesting’. Weedon in particular would be fun, with double reverse curves at, I guess, 110mph (vs 100mph normal, 120 EPS)

 

[Railperf]

All of which is quite advanced in the planning and delivery for south of Weaver as mentioned in other threads which is speed board changes only. The 221 differential will go and it will be saw tooth regardless as no one in considering track changes.

So 221s will 'drop' to the increased non EPS limits then. But of course none of this is useful to 397s which don't use WCML South of Weaver anyway.

 

[The Planner]

So 221s will 'drop' to the increased non EPS limits then. But of course none of this is useful to 397s which don't use WCML South of Weaver anyway.

Yes, though along the same lines, 221s with tilt won't be south of Weaver so it doesnt make any difference.

 

[a_c_skinner]

Pretty much any journey running at full up to 125mph speeds is "lively" north of Newcastle

But plainly safe and acceptable to passengers and train crew or it wouldn't continue.

 

[Railperf]

Yes, though along the same lines, 221s with tilt won't be south of Weaver so it doesnt make any difference.

So the change will occur before the 803's are introduced and established in service and not before then?

 

[LNW-GW Joint]

So the change will occur before the 803's are introduced and established in service and not before then?

It was stated previously that 3 concurrent speeds was the maximum allowed on route speed signage, so to introduce a new speed band means removing one of the existing ones - ie the 221 lower EPS differential limit, tilting 221s going off the premises with the arrival of 80x.
There are likely to be quite a few more signs than the current common 110/125EPS with a few EPS differentials for 221s at some locations.

 

[Bald Rick]

So the change will occur before the 803's are introduced and established in service and not before then?

Well that depends.

If the timetable is planned on the basis of 805s / 807s in service using the new speed profile, then it must be done before the timetable is implemented - indeed it must be confirmed to be happening whilst the timetable is being developed.

If the timetable is planned on 805s / 807s using the old speed profile, then it doesn’t matter. Albeit the timetable will be more difficult to write.

But the speed profile is, I imagine, only one of the issues of concern for introduction of the trains. Route clearance and power supply will be an issue, and no doubt other matters too.

 

[The Planner]

So the change will occur before the 803's are introduced and established in service and not before then?

Depends on what we do for Dec 22 as its planned to tinkered with on a wider scale. The 221 paths could be re-written with provisional 800 SRTs. As @Bald Rick says, there are other bits going on in the background such as power (Bushey) etc.

 

[hexagon789]

But plainly safe and acceptable to passengers and train crew or it wouldn't continue.

Well it must be safe, I'm not sure if I would call it acceptable really

It was stated previously that 3 concurrent speeds was the maximum allowed on route speed signage, so to introduce a new speed band means removing one of the existing ones - ie the 221 lower EPS differential limit, tilting 221s going off the premises with the arrival of 80x.
There are likely to be quite a few more signs than the current common 110/125EPS with a few EPS differentials for 221s at some locations.

So a new category just for 803s? I presumed it was just raising the non-EPS speeds that was the approach being taken.

 

[Bald Rick]

So a new category just for 803s? I presumed it was just raising the non-EPS speeds that was the approach being taken.

It’s going to be an ‘MU’ speed.

 

[LNW-GW Joint]

Well it must be safe, I'm not sure if I would call it acceptable really
So a new category just for 803s? I presumed it was just raising the non-EPS speeds that was the approach being taken.

Raising the PS to 125 is probably not easily achieved on the WCML (else why tilt?).
So PS and EPS speeds will stay and you need a new profile in the middle for suitable stock.
That's how it works on the Birmingham loop.

 

[Railperf]

One of the Avanti controllers was telling me that they tend to diagram 390s with tilt/ TASS issues onto Liverpool services with little loss of time. But that is because they eat into pathing/ engineering and dwell times rather than any ability to keep the usual SRTs.

It’s going to be an ‘MU’ speed.

Be interesting to see how the TASS system on 221s will be modified then. Will 221 tilt and TASS remain activated?

 

[hexagon789]

It’s going to be an ‘MU’ speed.

That makes sense, then TPE 397s can use it

Raising the PS to 125 is probably not easily achieved on the WCML (else why tilt?).

I don't see why, other than producing a more sawtooth profile than with tilt

 

[Railperf]

That makes sense, then TPE 397s can use it


I don't see why, other than producing a more sawtooth profile than with tilt

It all hinges on how long those higher speed sections can be and the time savings revenue potential/ capacity improvement vs additional energy/ fuel costs and track/ train maintenance costs.
As an example there are places straight enough for 125mph but posted at lower limits due to adverse gradients and minimal chance of the traction reaching the higher speed uphill.

 

[Bald Rick]

That makes sense, then TPE 397s can use it

They could, if they went between Euston and Weaver Junction.

 

[Railperf]

So to clarify our understanding of the current situation:

1. Class 397's are certified for 125mph running where the infrastructure allows. But at present they are limited to the WCML - which does not allow more than 110mph for non-tilting stock
2. The speed limits between Euston and Weaver junction (situated between Crewe and Warrington BQ) are to be revised to allow more than 110mph for multiple units - primarily Avanti's new Hitachi built rolling stock. To enable this, the Class 221 EPS limit is to be dropped - leaving a Pendolino EPS limit/ a new MU limit replacing Class 221 EPS / and then most likely the existing blanket limit for all other trains.
3. Class 221's will have to run at the lower (MU) limit once the speed boards are changed - which may result in some slight journey time increases for services using those units.
4. Class 397's don't use any part of the route between Euston and Weaver Jn.
5. There are long term 'plans' to upgrade non EPS speeds above 110mph between Wigan NW and Carstairs - primarily for HS2 stock. Rail magazine contributor Gareth Dennis - claimed a non-EPS speed limit upgrade was due to be implemented last summer for Class 397's between Wigan and Carstairs - but this has not taken place yet and there seems to be no further detail or timeline on this.

 

[hexagon789]

It all hinges on how long those higher speed sections can be and the time savings revenue potential/ capacity improvement vs additional energy/ fuel costs and track/ train maintenance costs.
As an example there are places straight enough for 125mph but posted at lower limits due to adverse gradients and minimal chance of the traction reaching the higher speed uphill.

I did read a piece somewhere (Modern Railways?) that discussed this and explained why it wasn't customers effective to have EPS speeds in certain locations/stretches of the WCML.

They could, if they went between Euston and Weaver Junction.

I was thinking in terms of the grander full WCML project north and south, unless the northern project is likely to be vastly different in nature to that south of Weaver Jcn?

 

[LNW-GW Joint]

I was thinking in terms of the grander full WCML project north and south, unless the northern project is likely to be vastly different in nature to that south of Weaver Jcn?

It will be First Group who are paying for the changes, and there is probably money for Avanti but maybe not for TPE after their franchise travails.
Avanti also have double the size of affected train fleet than TPE.
We still don't know if journey times will be affected.
From September, Voyagers will be back to doing Euston-Chester in 1h58m (with stops at Milton Keynes and Crewe), which is my benchmark.

 

[Bald Rick]

It will be First Group who are paying for the changes

It can only ever be taxpayers or fare payers!

 

[Jozhua]

I don't think the top speed of these is that important. Their acceleration is excellent so suspect that they get to and stay at maximum speed quicker and the additional blast of extra 15mph won't have much effect on overall times

Likely not enough of a speed increase to justify ironing out the curves! - HSR to Scotland would be a logical next step if journey time reductions were that important, but I doubt this would happen on the west coast anyway.