TASS, its purpose and and its future

[Transilien]

The good news is that 390s still have another 15 years left in them, so that gives the industry at least 7 years to come up with a replacement... right? right????

Aren’t the HS2 trains going to replace the 390s?

 

[dk1]

Aren’t the HS2 trains going to replace the 390s?

There have been ideas about 390s using HS2 to capitalise on their 140mph capability and their superior speed once off it and north of Crewe.

 

[zwk500]

There have been ideas about 390s using HS2 to capitalise on their 140mph capability and their superior speed once off it and north of Crewe.

Have there? I thought the entire case for HS2 was based on achieving the 200mph+ capability of the line*, not to mention the lack of level boarding and ETCS, and the fact 390s aren't 200m long.

* - Yes, I know it's actually about capacity, but they've kind of tied themselves to the journey time masts now...

 

[Bald Rick]

There have been ideas about 390s using HS2 to capitalise on their 140mph capability and their superior speed once off it and north of Crewe.

That was firmly speculation.

 

[Bletchleyite]

That was firmly speculation.

It wasn't just speculation here, though; it was speculation by someone in the industry, thus carries a fair bit of weight compared to say me speculating. Who was it again? I forget.

 

[dk1]

It wasn't just speculation here, though; it was speculation by someone in the industry, thus carries a fair bit of weight compared to say me speculating. Who was it again? I forget.

I seem to recall the railway press picked up on said suggestion too.

 

[Zomboid]

It wasn't just speculation here, though; it was speculation by someone in the industry, thus carries a fair bit of weight compared to say me speculating. Who was it again? I forget.

I saw a suggestion from Chris Gibb that the 390s could be upgraded for 155 and would then run on HS2

Gibb plans HS2 alternative with 155mph Pendolinos

Former Virgin West Coast manager Chris Gibb is putting forward a radical alternative to the cancelled HS2 route between Birmingham and Manchester, writes Peter Plisner

www.railmagazine.com

There are worse ideas out there TBH.

 

[Elecman]

It wasn't just speculation here, though; it was speculation by someone in the industry, thus carries a fair bit of weight compared to say me speculating. Who was it again? I forget.

Chris Gibb

 

[Krokodil]

There have been ideas about 390s using HS2 to capitalise on their 140mph capability and their superior speed once off it and north of Crewe.

Why bother upgrading them (ETCS etc.) when they'll pretty much be end-of-life by then?

 

[Speed43125]

Why bother upgrading them (ETCS etc.) when they'll pretty much be end-of-life by then?

This file might be of interest from the proposal around a year ago.

 

[LNW-GW Joint]

Why bother upgrading them (ETCS etc.) when they'll pretty much be end-of-life by then?

I think the context was before the HS2 programme hit the buffers, so to speak, and options were being floated to expand the HS2 rolling stock fleet (for the Phase 2a/b scope) at low cost.
All this when HS2 was supposed to be opening by 2030-ish.

Also 390s show every sign of being strongly built and well-suited to the routes they operate on, with untapped potential for higher speeds.
We still don't know how the HS2 rolling stock programme will work out on the truncated Phase 1, with the unsuitable 8/16-car layout (and no tilt).
Just as HS2 construction began too early in the project cycle, the rolling stock was ordered before the true state of the project was acknowledged.

 

[dk1]

Why bother upgrading them (ETCS etc.) when they'll pretty much be end-of-life by then?

I suppose it all depends. Will be interesting to see how things play out although I personally doubt they’ll see service on HS2.

 

[RailWonderer]

Aren’t the HS2 trains going to replace the 390s?

When HS2 opens the majority of WCML services will use it but some legacy services from Euston with Pendolinos will stiill run. This was the plan published not too long ago, albeit the legacy services will be a heavily reduced frequency due to lack of paths on lines to Manchester, Liverpool and Scotland. I think fares will be priced to balance loads so one isn't too overcrowded and the other too quiet. When 390s are life expired, HS2 will be up and running* and a 110mph IC train will probably replace them.

*Someone tell me if I'm being optimistic.

 

[Pendomonium]

TASS may be specifically for tilting trains, but it provides overspeed protection for 125mph running as well. ORRs view is that removing a 221 (fitted) and replacing with a 80x (not fitted) was therefore a reduction in safety - however marginal - which is why the 80x have been unable to use the upgraded linespeed profiles specifically designed for them.

Its an argument based on technicality and nuance but it gives an idea of how it’s necessary to consider the widest picture when proposing a rolling stock change on a route, rather than rely on a narrow rules-based assumption (I.e. in this case, ‘TASS is for tilting stock and therefore not required for 80x.’)

This is going to be the difficulty on GWML when ATP reaches the end of its life as well - in theory 125mph running is perfectly safe without enhanced protection but the change from ‘having ATP’ to ‘not having ATP’ will similarly be seen as a deterioration of safety margin if there is nothing comparable such as ETCS to replace it.

Having only recently gotten into the thread regarding 390s now being passed for MU speed operations in non tilt mode, I decided to go ask some questions as to why they are not doing so. And this was the very root of the matter. TASS has created a standard, that must be bettered or at least replaced to avoid a perceived reduction in mitigation measures. A 390 running with TASS isolated has no such protection. The current push is for a Driver Advisory System to be used. The 80x fleet has this capacity, although the 805/807 DAS has a long way to go before it is useable. Potentially using DAS on the GWML fleet would be the mitigation required for the removal of ATP. For 390s there is no DAS. What could be used is a carry on device issued to drivers. However, this raises all sorts of safety, working condition & integration issues etc, which will require a lot of work & negotiation to resolve. Given ASLEF are having to represent drivers being disciplined for portable technology, they are absolutely resistant to the idea of another carry on device beyond the agreed company mobile that is inactive in a driving cab.

 

[dk1]

Having only recently gotten into the thread regarding 390s now being passed for MU speed operations in non tilt mode, I decided to go ask some questions as to why they are not doing so. And this was the very root of the matter. TASS has created a standard, that must be bettered or at least replaced to avoid a perceived reduction in mitigation measures. A 390 running with TASS isolated has no such protection. The current push is for a Driver Advisory System to be used. The 80x fleet has this capacity, although the 805/807 DAS has a long way to go before it is useable. Potentially using DAS on the GWML fleet would be the mitigation required for the removal of ATP. For 390s there is no DAS. What could be used is a carry on device issued to drivers. However, this raises all sorts of safety, working condition & integration issues etc, which will require a lot of work & negotiation to resolve. Given ASLEF are having to represent drivers being disciplined for portable technology, they are absolutely resistant to the idea of another carry on device beyond the agreed company mobile that is inactive in a driving cab.

DAS can be ignored as is only advisory. I only like it for the clock.

 

[HSTEd]

Given that the TASS system uses eurobalises transmitting an ETCS compatible message format (using a packet number reserved for national system specific messages), wouldn't fitting the CLass 80x trains to obey TASS be a software issue?

They will all have ETCS compatible computers won't they?

On the other hand, its another example of the UK safety ratchet at work

 

[Sorcerer]

Given that both TASS and ETCS require the use of Eurobalises, would it be theoretically possible to have some kind of integration where any future tilting trains could use the ETCS signalling to determine where to tilt and by how many degrees? I know this wouldn't be precedented since European Pendolino trains don't require smart tilt systems, but if it were somehow possible it could allow future tilting trains without the need for TASS which is something Alstom and Network Rail don't seem too keen on supporting further developments of. It's all hypothetical but it is a question I've pondered for a while now.

 

[Tilting007]

Having only recently gotten into the thread regarding 390s now being passed for MU speed operations in non tilt mode, I decided to go ask some questions as to why they are not doing so. And this was the very root of the matter. TASS has created a standard, that must be bettered or at least replaced to avoid a perceived reduction in mitigation measures. A 390 running with TASS isolated has no such protection. The current push is for a Driver Advisory System to be used. The 80x fleet has this capacity, although the 805/807 DAS has a long way to go before it is useable. Potentially using DAS on the GWML fleet would be the mitigation required for the removal of ATP. For 390s there is no DAS. What could be used is a carry on device issued to drivers. However, this raises all sorts of safety, working condition & integration issues etc, which will require a lot of work & negotiation to resolve. Given ASLEF are having to represent drivers being disciplined for portable technology, they are absolutely resistant to the idea of another carry on device beyond the agreed company mobile that is inactive in a driving cab.

Interesting… thank you.

 

[Roast Veg]

At risk of too detailed an answer, both ETCS and TASS use the same type of Balise, but each Balise can/will have a data type, and if the train isn't looking for that type, it will ignore the message.

A prime example is Edinburgh Haymarket where there are ETCS Balises for Hitachi Units, TASS Balises for Avanti.

I don't know if Balises can have more than one message type?

They can definitely hold multiple packet types - next signal aspect and upcoming speed restriction, for example.

Given that the TASS system uses eurobalises transmitting an ETCS compatible message format (using a packet number reserved for national system specific messages), wouldn't fitting the CLass 80x trains to obey TASS be a software issue?

They will all have ETCS compatible computers won't they?

On the other hand, its another example of the UK safety ratchet at work

I'm not sure why you'd do this as opposed to just using the correct message format for speed restrictions as part of a proper ETCS fitment.

Given that both TASS and ETCS require the use of Eurobalises, would it be theoretically possible to have some kind of integration where any future tilting trains could use the ETCS signalling to determine where to tilt and by how many degrees?

By the sounds of it, TASS already uses ETCS compatible technology in all ways that are practical. A future ETCS fitment of the WCML could continue to provide TASS packets, but if the infrastructure owners aren't interested in continuing to maintain the systems to provide that data then it won't happen.

 

[HSTEd]

I'm not sure why you'd do this as opposed to just using the correct message format for speed restrictions as part of a proper ETCS fitment.

Because apparently (as indicated in post #15 of this thread) is that 80x trains are unable to use the higher speeds available because of a lack of TASS overspeed protection.

There is unlikely to be an ETCS installation on the west coast for a rather long time give how slow the programme is progressing. So we should probably do somethign in the interim.

 

[Pendomonium]

DAS can be ignored as is only advisory. I only like it for the clock.

Quite. I gather GW drivers are encouraged to use it via a bonus. I also gather that most dont.

 

[dk1]

Quite. I gather GW drivers are encouraged to use it via a bonus. I also gather that most dont.

Crikey!! Will they stop at nothing?

 

[eldomtom2]

TASS may be specifically for tilting trains, but it provides overspeed protection for 125mph running as well. ORRs view is that removing a 221 (fitted) and replacing with a 80x (not fitted) was therefore a reduction in safety - however marginal - which is why the 80x have been unable to use the upgraded linespeed profiles specifically designed for them.

Its an argument based on technicality and nuance but it gives an idea of how it’s necessary to consider the widest picture when proposing a rolling stock change on a route, rather than rely on a narrow rules-based assumption (I.e. in this case, ‘TASS is for tilting stock and therefore not required for 80x.’)

This is going to be the difficulty on GWML when ATP reaches the end of its life as well - in theory 125mph running is perfectly safe without enhanced protection but the change from ‘having ATP’ to ‘not having ATP’ will similarly be seen as a deterioration of safety margin if there is nothing comparable such as ETCS to replace it.

If this is true it seems to be a problematic way of managing safety - if the railways can never remove a safety system, no matter if installing it would never pass a cost-benefit analysis, then not only will money be taken up that could go into more effective safety measures but the railways will also become more and more uneconomic to operate, with negative effects on ridership and government support.

 

[Pendomonium]

If this is true it seems to be a problematic way of managing safety - if the railways can never remove a safety system, no matter if installing it would never pass a cost-benefit analysis, then not only will money be taken up that could go into more effective safety measures but the railways will also become more and more uneconomic to operate, with negative effects on ridership and government support.

It is the crux of many issues. An introduced safety system like TASS sets the benchmark going forward. It can only be replaced with something of equal or better to avoid increasing risk.

 

[Roast Veg]

I don't think it's that simple. Line speed increases all carry increased risk regardless of the fitment of train protection.

 

[HSTEd]

If this is true it seems to be a problematic way of managing safety - if the railways can never remove a safety system, no matter if installing it would never pass a cost-benefit analysis, then not only will money be taken up that could go into more effective safety measures but the railways will also become more and more uneconomic to operate, with negative effects on ridership and government support.

This sort of behaviour is seen in all sorts of "safety case" industries. Especially in nuclear.

 

[Egg Centric]

Quite. I gather GW drivers are encouraged to use it via a bonus. I also gather that most dont.

It must be pretty annoying if they're turning down free money to use it? I would do a lot of mildly annoying things for free money...

 

[The exile]

They certainly had a vision for the future.

Even the 220/221s that transferred over to XC and have taken an absolute hammering every day for the last 15 years are still going strong, if looking a little rough around the edges.

An awful lot less rough round the edges than the XC ones they’re augmenting.

 

[Bletchleyite]

It very did my friend and I fear we’ll never see the likes again. With so much to go wrong many (and not just the usual doom mongers) thought it would be a poisoned chalice but it has proved them wrong.

West Coast has gone well. XC has gone terribly. 50% isn't bad

 

[Pendomonium]

It must be pretty annoying if they're turning down free money to use it? I would do a lot of mildly annoying things for free money...

In this case mildly annoying may lead to a load more monitoring and mildly annoyingly having to explain yourself as to why you didnt react to DAS.