Tilting High Speed Stock

[Blamethrower]

Interesting announcement from Alstom today:

http://www.imeche.org/news/news-art...n-from-hs2-onto-the-rest-of-the-rail-network?

Alstom has said its tilting train design would be suitable for the project and would allow for increased speeds
Alstom has said its TGV high-speed tilting trains could solve potential issues with rolling stock travelling from the HS2 line onto existing rail infrastructure.

The competition for the £7.5 billion contract to design and build HS2 rolling stock is expected to launch next year, with a mix of “classic-compatible” trains that would run across HS2 and the existing network and “captive” trains that would operate just on the high-speed line.

Alstom, which has already put forward an idea for a double-decker captive train, has said its tilting train design would be suitable for HS2 and allow for increased speeds when running from the high-speed route onto traditional lines.

The train would be based on the design it is making for the US Amtrak network.

Jaime Borrell, product manager of high-speed trains at Alstom, said: “If the priority for HS2 is journey time, including on tracks outside of HS2, then the tilting system can bring time reduction.”

Alstom’s Tiltronix anticipative tilting technology allows the train to manoeuvre around curves safely and more comfortably up to the maximum speeds set for the line. Trains usually slow down on curves to prevent unpleasant lateral acceleration. “We can run analytics and upgrade the overall speed of the line to reduce journey time,” said Borrell. “It is then the choice of the operator to fully dedicate the saved journey time to the final trip or to keep some margin back to increase punctuality on the line.”

Alstom’s tilting trains have been built to achieve mainline speeds of around 300km/h – the HS2 trains are expected to travel at up to 360km/h. However, Borrell said Alstom is able to develop tilting trains capable of faster speeds.

HS2 said: “There are no technical barriers to our specification for a classic-compatible train to have the same high-speed performance as a captive train running only on HS2.”

Last month, Professor Roderick Smith of Imperial College London said that running classic-compatible trains on and off the high-speed line would create pinch points, where late-running trains would delay HS2 trains as they transferred from the existing network.

 

[Bletchleyite]

So basically a high-speed Pendolino? Should work well I'd imagine; the technology is well proven, just need it to be able to go a bit quicker.

 

[edwin_m]

This has been discussed in the letters column of Modern Railways in recent months. The question is whether the time saving justifies the extra weight and cost of a tilting unit.

Probably the only time saving is between Preston and Glasgow/Edinburgh. Going by the differences in London journey times a non-tilting classic compatible as proposed by HS2 Ltd would have a non-stop journey time of about 2hr 10min on this leg, and a Pendolino can do Preston-Glasgow in 2hr 20min with three stops. Going by those figures there is no benefit, except in the unlikely event that the Alstom unit can improve significantly on Pendolino timings.

 

[The Planner]

It also assumes that we wont do anything to the infrastructure north of Gooborne to allow higher non tilt speeds.

 

[BananaRepublic]

The classic compatible stock will also be used on routes with much shorter runs off the HS2 lines; e.g. Liverpool, Newcastle etc, where tilt would be of no use whatsoever.

Only the Scottish services could potentially benefit from tilt and that's marginal, as described by others above.
It seems pointless to burden the whole classic compatible fleet with the extra cost, weight and complexity of tilt, just for a proportion of the routes on which it will be used on.

 

[Chris125]

It's a good way for Alstom to get some cheap publicity, but it's pretty inconceivable that a high speed tilt design could be justified for a relatively minor benefit on a fraction of the route miles these trains will operate.

 

[LNW-GW Joint]

How do you sell longer journey times to the Scots (and anybody living north of Crewe)?
There will also be a need for a 390 replacement in a similar timescale (they will be 25 years old at least by the time HS2 reaches Crewe).

 

[The Planner]

The classic compatible stock will also be used on routes with much shorter runs off the HS2 lines; e.g. Liverpool, Newcastle etc, where tilt would be of no use whatsoever.

Handsacre to Liverpool vs Stafford isnt that short....

 

[Blamethrower]

So basically a high-speed Pendolino? Should work well I'd imagine; the technology is well proven, just need it to be able to go a bit quicker.

That's what I thought

With the question of whether a 10 minute saving is worth it or not, is there any way to compare a pretendolino against a pendolino north of preston? as in a tilt vs non-tilt

Would tilt help between Newcastle and Edinburgh?

How about Birmingham to Bristol? (assuming a cross country HS service from Newcastle - Bristol via HS2 and then Bham new street)

Just trying to gauge whether tilting stock can be used as an enabler for new services once HS2 is built

 

[absolutelymilk]

How do you sell longer journey times to the Scots (and anybody living north of Crewe)?
There will also be a need for a 390 replacement in a similar timescale (they will be 25 years old at least by the time HS2 reaches Crewe).

Presumably the current London - Glasgow stopping service will stay as it is and an extra HS2 service will do Preston - Glasgow without stopping in a slightly shorter time. I'm not sure what you mean about the 390 replacement, are you suggesting that HS2 and Virgin use the same stock?

 

[Chris125]

How do you sell longer journey times to the Scots (and anybody living north of Crewe)?

I'm sure far more Scots and others along the route will benefit from the journeys which HS2 speeds up than those slightly slower due to a lack of tilt, and even they could be mitigated by upgrades to the northern WCML which will be required anyway.

There will also be a need for a 390 replacement in a similar timescale (they will be 25 years old at least by the time HS2 reaches Crewe).

Yes, and it's quite conceivable that such trains will not tilt - cheaper, lighter trains may well make more sense for the demand and service patterns post-HS2.

 

[BananaRepublic]

...Would tilt help between Newcastle and Edinburgh?...

Will any CC HS2 services routing up the eastern arm, progress beyond Newcastle?
I thought any diversion of IC services to/from Scotland onto HS2, would be running via the western arm (the WCML side).?

....How about Birmingham to Bristol? (assuming a cross country HS service from Newcastle - Bristol via HS2 and then Bham new street)......

There is no plan to link HS2 to New St.
HS2 is a totally segregated railway, with links into the national classic network at limited access points.
Any HS service from Newcastle to Birmingham will have to run into Curzon St.

 

[edwin_m]

Will any CC HS2 services routing up the eastern arm, progress beyond Newcastle?
I thought any diversion of IC services to/from Scotland onto HS2, would be running via the western arm (the WCML side).?

Correct.

There is no plan to link HS2 to New St.
HS2 is a totally segregated railway, with links into the national classic network at limited access points.
Any HS service from Newcastle to Birmingham will have to run into Curzon St.

It's only discussion on forums such as this one but the suggestion has been made of a connection east of Birmingham so HS2 trains from the north can continue into New Street and onwards to Bristol, assuming that route is electrified. In my personal view it would be a good piece of future proofing to at least make provision for that to be added later.
--- old post above --- --- new post below ---

How do you sell longer journey times to the Scots (and anybody living north of Crewe)?

According to my previous post, the longer journey time would only be a handful of minutes north of Preston in Phase 2B. If anyone can see any flaw in that posting, please point it out - I'm not proud and I was quite surprised at the answer.

It would be more in Phase 2A when Scotland trains join/leave HS2 at Crewe, and even more if they still do so at Handsacre in Phase 1, though the time saving on HS2 itself will outweigh it in each case.

So my conclusion is that the tilting equipment on a classic compatible would only be of use between 2027ish and 2032ish, and unlikely to be worthwhile for such a short period.
--- old post above --- --- new post below ---

Handsacre to Liverpool vs Stafford isnt that short....

Still a lot shorter than Preston to Glasgow, and probably less curvy too.

 

[route:oxford]

According to my previous post, the longer journey time would only be a handful of minutes north of Preston in Phase 2B. If anyone can see any flaw in that posting, please point it out - I'm not proud and I was quite surprised at the answer.

Only a few minutes if the Scotland ends at Edinburgh or Glasgow.

If a unit is classic compatible, why not run all the way through to Aberdeen and Inverness?

Transport Scotland might be willing to upgrade elements of the routes to make them tilt compatible.

 

[LNW-GW Joint]

According to my previous post, the longer journey time would only be a handful of minutes north of Preston in Phase 2B. If anyone can see any flaw in that posting, please point it out - I'm not proud and I was quite surprised at the answer.
It would be more in Phase 2A when Scotland trains join/leave HS2 at Crewe, and even more if they still do so at Handsacre in Phase 1, though the time saving on HS2 itself will outweigh it in each case.
So my conclusion is that the tilting equipment on a classic compatible would only be of use between 2027ish and 2032ish, and unlikely to be worthwhile for such a short period.
Still a lot shorter than Preston to Glasgow, and probably less curvy too.

It's quite a leap to presume that HS2 will open north of Handsacre, when all the parliamentary process has still to be negotiated.
Handsacre-Glasgow/Edinburgh is getting on for 300 miles of winding WCML (and 70-odd miles Handsacre-Manchester/Liverpool).
I think the tilting differential is a lot more than 10 minutes over that stretch, more like 20-30 minutes.
The proposed extensions finish at Crewe or Golborne, well south of Preston.

Much is made of potential new sections of the WCML, but that is equally uncertain, and the HS2 policy is not to fund classic network upgrades.
A Lancaster-Carlisle bypass isn't going to happen for decades.

All Alstom are saying (as they would) is that they have a solution for all combinations of HS2 train, without penalty for tilting capability.
It will be at least 5 years before any orders get placed.
I would hope a holistic approach is taken over the train specification.
Tilting was ruled out of the IEP spec, mainly because it was a design aimed at GWML/ECML services.
A tilting option would have made upcoming decisions on ICWC rolling stock a lot simpler.

There is (or was) a tilting faction in NR and the TOCs, dominating planning for the WCML.
There is also an anti-tilting faction, including the HS2 lot and the "HST brigade".
Again, HS2 is against any factor which increases costs, without thinking about operational flexibility for the classic network.
The DfT will have to make some provision for this in the upcoming ICWC franchise spec (ie buy more tilting stock or not).

RENFE's operation of its network demonstrates what range of high speed solutions can be devised, with a combination of dedicated, bi-mode, bi-gauge and tilting options all adding to comprehensive system integration and through services across Spain.

 

[The Planner]

It's quite a leap to presume that HS2 will open north of Handsacre, when all the parliamentary process has still to be negotiated.

Hybrid Bill for 2A is being prepared now, you cannot have two running concurrently apparently.

It will be at least 5 years before any orders get placed.

It will be well before that, HS2 intend to be testing for a significant period of time before opening.

 

[edwin_m]

It's quite a leap to presume that HS2 will open north of Handsacre, when all the parliamentary process has still to be negotiated.

By the time the trains are ordered for Phase 1, we should know whether Phase 2 is happening or not as the Bill will have been to Parliament (or not).

Handsacre-Glasgow/Edinburgh is getting on for 300 miles of winding WCML.
I think the tilting differential is a lot more than 10 minutes over that stretch, more like 20-30 minutes.
The proposed extensions finish at Crewe or Golborne, well south of Preston.

Assuming Phase 2 does go ahead, Handsacre will only be the limit of high speed infrastructure for Scotland trains for a year or two, so not really significant in the specification of a train that will last for decades. (I'm aware that is exactly what has happened to the IEP for GW, but it was fitting extra diesel engines that were always allowed for in the design, not a total re-work of the bodyshell and running gear to incorporate tilt.) In fact I wouldn't be surprised if it opened through to Crewe on Day 1, allowing Handsacre to be simplified as it would never carry more than a couple of trains an hour.

I do agree, as I posted above, that the time saving for a tilting train coming off HS2 at Crewe would be greater, but this is still only over a five-year period. Golborne to Preston is pretty straight apart from the curves through Wigan where there is no EPS differential at present so tilting trains can't run faster. There are EPS north of Coppull but this is probably straight enough that non-tilting trains to run faster if needed. Hence I think the only potential gains are north of Preston, but as per my original posting was rather surprised to find they are very small.

All Alstom are saying (as they would) is that they have a solution for all combinations of HS2 train, without penalty for tilting capability.
It will be at least 5 years before any orders get placed.

I agree with that except for "without penalty". There would be a significant increase in capital cost, in weight (hence running cost), and possibly in passenger space. The interior would have to be smaller, though hopefully good design could make it more like a Meridian than a Pendolino. For those reasons any tilting variant would probably be a sub-fleet rather than the full fleet of classic compatibles, increasing costs further.

I think in view of the apparently small benefit and the possibly large cost that it is entirely reasonable to be somewhat cynical about this.

 

[Chris125]

Much is made of potential new sections of the WCML, but that is equally uncertain, and the HS2 policy is not to fund classic network upgrades.
A Lancaster-Carlisle bypass isn't going to happen for decades.

Extra capacity will almost certainly be necessary on the northern WCML regardless of who pays for it - failing to satisfy that demand would be a much greater issue in the decades ahead than HS2 trains lacking tilt.

 

[SpacePhoenix]

Provided HS2 gets built, will there then be any need for tilting stock on the WCML?

 

[randyrippley]

A Lancaster-Carlisle bypass isn't going to happen for decades.

If ever - very hard to see where it could be put, other than alongside the existing route via Shap. You've got three possible valleys north from Preston/Lancaster: the Ribble (which would land you at Ribblehead), the Lune (which would send you via Shap/Tebay) or the Lake District central valley north of Windermere via Dunmail Raise. All bring severe environmental and engineering issues.
Only other options would be via Manchester - Leeds and then up the east coast.........unless you wanted to dogleg back to the west coast via Stainmore or Redmire. Not very sensible.
The only "sensible" answer is a tidal power-generating barrier across Morecambe Bay from Heysham or Fleetwood to Barrow, and then a new coastal line around Cumbria. Still a lot of environmental issues but probably more do-able. Damned expensive though and you'd have to destroy a RAMSAR wildlife refuge to do it

 

[Mikey C]

It's a tricky one, as without tilt the new Classic compatible trains will be slower on the conventional lines, which will be include the Birmingham to Crewe section until Stage 2 of HS2 is built.

On the other hand, it adds cost and complication, and makes the interior smaller