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Do Class 80x units have a theoretical top speed of 140mph on electric power?

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supervc-10

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Don't the 80x family have a theoretical top speed of 140mph on electric? Like the Javelins?

Edit:
This was split off a thread about the 769s, which have a different top speed on electric to on diesel. I know the 80x are running at 125mph on both diesel and electric, but I'm sure I remember something about them being designed for 140mph.
 
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Speed43125

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They current gearing is for 125 mph(or strictly speaking, 200 km/h, so around 124mph). A big reason they are so much faster at accelerating than IC 225 sets is because they are geared properly, rather than 91s which are geared for 140 mph running (and seemingly are able to sustain 155+ running with the current gearing too).
The 80x is designed to be 140 ready, so a change in gearing and it should have no issues doing 140, if we eventually get around to signalling upgrades that permit that.
 

hexagon789

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Don't the 80x family have a theoretical top speed of 140mph on electric? Like the Javelins?

Edit:
This was split off a thread about the 769s, which have a different top speed on electric to on diesel. I know the 80x are running at 125mph on both diesel and electric, but I'm sure I remember something about them being designed for 140mph.

The 80x are capable of 140mph on electric, they were specced to be able to run at that speed and I believe originally 110 on diesel for the bi-modern types.
 

class26

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Network Rail has selected Siemens and Atkins as their partners for the roll-out of ETCS L2 along the East Coast Main Line. The first phase covers resignalling London Kings Cross to Stoke Summit. :)

But it will need more than ETCS to enable 140 mph. Level crossings must also go before speeds higher than 125 mph can be permitted.
There some lengthy stretches on the southern part of the ECML without crossings where it might be worth going faster such as Tallington- Stoke. Others will know of more examples perhaps ?
 

jimm

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The 80x are capable of 140mph on electric, they were specced to be able to run at that speed and I believe originally 110 on diesel for the bi-modern types.

In fact, the IEP technical specification says the following about maximum speeds of the trains.

3.8 Performance

The IEP Trains must have a maximum service speed of at least 125mph and shall be able to achieve that speed on the whole of the IEP Network. The requirement to be able to operate at 125mph applies during operation in Standard Mode and Locomotive Hauled Mode.

It is accepted that 125mph may not be achieved under the following circumstances:
  • on adverse gradients;

  • in excessive headwinds;

  • in the case of an IEP Train containing Bi-mode IEP Units operating in Self Power Mode;

  • in the case where more than 312m of the IEP Train length comprises of Electric IEP Units;

    • where any hauling Locomotive has insufficient tractive effort or maximum speed to allow 125mph to be achieved;
• in the event that the braking performance of an IEP Train is incompatible with the the infrastructure at 125mph due to the braking performance of a hauling locomotive;
  • under Adverse Infrastructure Conditions;

  • where, in the event of failure of the IEP Train, it is not possible to raise two pantographs at the maximum pantograph spacing permitted by the train formation. In this event, subject to the other provisos of this provision, at least 100mph must be achieved if the pantograph spacing is 75m or greater and no less than 80mph shall be achieved for lesser spacings; and

  • in the event that it is not possible to show compatibility between the pantograph and the infrastructure, when an IEP Train is operating with two pantographs raised, on any portion of the Great Western Main Line between Paddington and Airport Junction where the line speed is greater than 100mph. In this event, the IEP Train shall be capable of 100mph or the speed at which operation is shown to be compatible with the overhead line, whichever is greater.

    The IEP Trains operating under electric power shall through modification be capable ofhigher speeds than 125mph to allow for possible line speed upgrades or new lines with higher speed limits being available. The capability of the IEP Train in this regard, together with a summary of the modifications required shall be detailed through the Design Process.


From Page 21 at https://assets.publishing.service.g...s/attachment_data/file/82840/tts-redacted.pdf
 

59CosG95

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But it will need more than ETCS to enable 140 mph. Level crossings must also go before speeds higher than 125 mph can be permitted.
There some lengthy stretches on the southern part of the ECML without crossings where it might be worth going faster such as Tallington- Stoke. Others will know of more examples perhaps ?
Tallington - Stoke is the most obvious candidate for 140mph in the first instance, as the track along that length has a complete lack of level crossings and is plain line on all 4 tracks. North of Doncaster, the 'Selby Diversion' (i.e. Temple Hirst Jn - Colton Jn) could be another contender, but as there's no ETCS announced for that section of route yet, it's more of an academic proposal.

South of Peterborough, you'd probably have to vastly reduce the number of crossovers on the ECML to make 140mph worthwhile, and you'd have to iron out the remaining bottlenecks (Welwyn Viaduct & Tunnels; Huntingdon-Woodwalton; Holme Jn-Fletton Jn) in order to achieve any meaningful time savings without being at the expense of capacity. And that's before the myriad number of level crossings from Arlesey to Peterborough are closed...
 

samuelmorris

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I believe the actual maximum speed of the AT300 as a product is 240km/h so almost 150mph, but that may not apply to the 26m vehicle length variant. Certainly 140 is as much as they'd ever be likely to see in the UK, if they were ever upped from 124.
 

Meerkat

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I still can’t believe that there are so many level crossings on the ECML! Especially as many are in rural/semi-rural areas
 

MarlowDonkey

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I still can’t believe that there are so many level crossings on the ECML!

Level Crossings are still in evidence on the Berks & Hants, but that's limited to 110 mph because it isn't straight.

There's none between Paddington and Reading, but are there any west of Reading on the lines to Bristol and Cardiff?
 

59CosG95

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Level Crossings are still in evidence on the Berks & Hants, but that's limited to 110 mph because it isn't straight.

There's none between Paddington and Reading, but are there any west of Reading on the lines to Bristol and Cardiff?
Steventon (Stocks Lane, The Causeway). 'Nuff said.

There are a few between Bath & Bristol as well AIUI, but there's no point running 140mph along there!
 

Mikey C

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Why are level crossings a no-no at 140mph, but perfectly ok at 125mph which is still incredibly fast when compared to other surface transport?
 

quantinghome

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Why are level crossings a no-no at 140mph, but perfectly ok at 125mph which is still incredibly fast when compared to other surface transport?
Because at some point the speed is so high that level crossings are deemed unsafe. Whatever speed is decided on, it would always be possible to ask your question. But that doesn't mean it's the wrong decision. Otherwise you could repeat the argument and end up with level crossings being permitted at 200mph.

The other point is that higher speeds would mean longer stopping distances and the barriers having to come down earlier. Coupled with increasing train frequencies, the level crossing becomes functionally useless as it ends up closed most of the time.
 

II

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How much of an obstacle would station platform safety be for 140mph running? If costly modifications were required, that in itself might well be enough to scupper any thoughts of running at 140mph on the GWML.
 

hexagon789

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How much of an obstacle would station platform safety be for 140mph running? If costly modifications were required, that in itself might well be enough to scupper any thoughts of running at 140mph on the GWML.

France runs TGVs at 220km/h (136.7mph) through open platforms on some lines and I think Germany might run ICEs at 230 (142.9mph) through some stations sans barriers.
 

LNW-GW Joint

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Don't the 80x family have a theoretical top speed of 140mph on electric? Like the Javelins?

And the Pendolinos in tilt mode.
Also limited to 125mph by signalling constraints.
They were procured for a 140mph tilting WCML which never materialised.
 

II

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Thanks, I'm just wondering whether those platforms are purpose built for high speed running (i.e. nice and wide)? Somewhere with fairly narrow, or very busy, platforms Slough and Maidenhead or somewhere like Goring & Streatley are examples that might be different?
 

hexagon789

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And the Pendolinos in tilt mode.
Also limited to 125mph by signalling constraints.
They were procured for a 140mph tilting WCML which never materialised.

And InterCity 225, which are marked for 140 on the data panels. I'm not sure if 80x are marked first 125 or 140 on the data panels though, I haven't managed to find a photo as yet
 

hexagon789

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Thanks, I'm just wondering whether those platforms are purpose built for high speed running (i.e. nice and wide)? Somewhere with fairly narrow, or very busy, platforms Slough and Maidenhead or somewhere like Goring & Streatley are examples that might be different?

The approaches to Paris Est off the LGV Est starts out with a 220 limit when the LGV joins the classic line and then progressively reduces speed. Though it seems the fast lines (220km/h) are not given platforms at the likes of Vaires-Torcy.

Perhaps something on the classic line to Boreaux? That used to have some 210/220 sections for TGVs.
 

Mikey C

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Because at some point the speed is so high that level crossings are deemed unsafe. Whatever speed is decided on, it would always be possible to ask your question. But that doesn't mean it's the wrong decision. Otherwise you could repeat the argument and end up with level crossings being permitted at 200mph.

The other point is that higher speeds would mean longer stopping distances and the barriers having to come down earlier. Coupled with increasing train frequencies, the level crossing becomes functionally useless as it ends up closed most of the time.

It just seems that allowing 125mph running was a compromise/pragmatic decision rather than one based on hard facts

Is someone had decided that 100mph was the safe limit, then effectively most of our inter city network would be reduced to 100mph as the cost of replacing all the level crossings would be horrendous, and the disruption caused by closing them unacceptable.
 

ac6000cw

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It just seems that allowing 125mph running was a compromise/pragmatic decision rather than one based on hard facts

I assume it's basically grandfather rights - regular 125 mph running started nearly 45 years ago with the first GW mainline HST services in 1976.

The point of the HST was that they could run at 125 mph on largely the existing infrastructure (as there wasn't the money to replace it all), so after careful consideration and testing it was deemed safe to run at 125 mph through most existing platforms, full-barrier crossings, tunnels and bridges, using existing colour light signalling and AWS protection (but they did originally have another driver in the cab).

It was 125 mph operation achieved on a relative shoestring in a different world back then (and a much less busy railway than today), but without it BR's InterCity services would likely have continued their downward spiral of decline.
 
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swt_passenger

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How much of an obstacle would station platform safety be for 140mph running? If costly modifications were required, that in itself might well be enough to scupper any thoughts of running at 140mph on the GWML.
Station platforms are covered by existing standards, they’re ok being passed at 140 mph, but with the restriction that above 125 mph no one can be allowed on the platform.
 

II

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Station platforms are covered by existing standards, they’re ok being passed at 140 mph, but with the restriction that above 125 mph no one can be allowed on the platform.

Thanks. I wonder if that restriction effectively means no likelihood of 140mph on the GWML then? With the possible exception of some sections between Didcot Parkway and Bristol Parkway/Chippenham which might not be enough to worth bothering about.
 

hexagon789

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Thanks. I wonder if that restriction effectively means no likelihood of 140mph on the GWML then? With the possible exception of some sections between Didcot Parkway and Bristol Parkway/Chippenham which might not be enough to worth bothering about.

Either the limit remains at 125 through stations or some means of closing off the platforms? Perhaps then 140 could be allowed.
 

swt_passenger

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Either the limit remains at 125 through stations or some means of closing off the platforms? Perhaps then 140 could be allowed.
I suspect the minor stations such as those between Reading and Didcot that presently have a fairly “porous” safety fence would have to have it replaced with a far more secure version. But a station where most but not all fast trains call would be problematical if people couldn’t be cleared from a platform before the next through train was due. Can’t see a safe solution to that...
 

hexagon789

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I suspect the minor stations such as those between Reading and Didcot that presently have a fairly “porous” safety fence would have to have it replaced with a far more secure version. But a station where most but not all fast trains call would be problematical if people couldn’t be cleared from a platform before the next through train was due. Can’t see a safe solution to that...

Platform edge screens?
 

II

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That’s about the only really safe solution, but then you have issues with differing length of trains, door positions, stopping accuracy etc etc...

As well as cost...

I guess if you somehow modified Didcot Parkway and closed off the main line platforms at Tilehurst, Goring and Cholsey unless a train was calling (staff to open up as and when necessary?) that would give you a clear run from Reading to Swindon (level crossings aside) which along with sections the other side of Swindon might just about be worth it? As long as no more stations are built, except for Grove which could be built on the up and down relief lines. The formation will also need to be up to it - there are some curves you can certainly feel at 125mph in the Pangbourne area.

I can see it being more hassle and cost to much to be worth it though.
 

AlexNL

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That’s about the only really safe solution, but then you have issues with differing length of trains, door positions, stopping accuracy etc etc...
There are vertical platform screens, which look more like a sort of net. These could be installed along the length of a platform and will be able to accommodate any kind of train. Here's a video of a trial setup in South Korea:

 
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