Why doesn't the e320 Eurostar run at 200mph?

[tornado]

Hi,

A simple question, perhaps I've missed it somewhere. When the e320 were introduced we were promised 15 minutes quicker London-Paris using the 200mph capability once all the previous rolling stock was withdrawn on that route. This doesn't seem to have happened. Does anyone know why?

 

[StephenHunter]

I don't think the line has been upgraded to 200mph capability, certain not in the UK. Also, the 373s are still in play.

 

[Richard Scott]

Can't believe running at an extra 14mph will save 15 minutes?

 

[43066]

LGV Nord is still 300 kph max, as I recall from a previous discussion on here.

Would the extra 20kph per hour max speed really equate to a 15 minute time saving? That doesn’t seem likely given the relatively short distance, the lower speeds in the London tunnels, the channel tunnel itself, the “classic lines” approach to Paris etc.?

Can't believe running at an extra 14mph will save 15 minutes?

Beat me to it!

 

[hexagon789]

Hi,

A simple question, perhaps I've missed it somewhere. When the e320 were introduced we were promised 15 minutes quicker London-Paris using the 200mph capability once all the previous rolling stock was withdrawn on that route. This doesn't seem to have happened. Does anyone know why?

Neither HS1 nor the LGV Nord permit such speeds. I'm also not convinced that a 20km/h increase would deliver a 15 minute saving over what is not really that long a distance strictly speaking and allowing for the 160km/h maximum for 50.5km through the Channel Tunnel.

Edit: seems we're all thinking along similar lines

 

[TRAX]

If I am not mistaken there is no project to upgrade the LN3 to 320 kph.

 

[Ianno87]

Can't believe running at an extra 14mph will save 15 minutes?

300kph is 12 seconds per kilometre.
320kph is 11.25 seconds per kilometre.

It's 200km from the start of LGV Nord at Gonesse to the Fretin Triangle at Lille.

If the whole lot were upgraded, that's a whole 2.5 minutes to be had...

 

[tornado]

I guesss you also need to consider if the acceleration is superior?

Newspaper article from e320 introduction (2014):

"Eurostar unveils 200mph e320 trains to knock 15 minutes off journey from London to Paris"

Eurostar Unveils the Newest High-Speed Train in Europe

It's the first complete redesign in the train's 22-year history.

www.cntraveler.com

 

[Ianno87]

I guesss you also need to consider if the acceleration is superior?

Newspaper article from e320 introduction (2014):

"Eurostar unveils 200mph e320 trains to knock 15 minutes off journey from London to Paris"

Eurostar Unveils the Newest High-Speed Train in Europe

It's the first complete redesign in the train's 22-year history.

www.cntraveler.com

The article text itself refers to the "average" journey time.

The only way I could fathom even getting close to 15 minutes would be all London-Paris trains running non-stop, i.e. none stopping at Ebbsfleet/Ashford, which would save roughly 7/9 minutes respectively, combined with speed increases.

Doubt acceleration would make that much difference, with the relatively few stops the train makes (plus getting away from the lower speed areas through the tunnel and Lille). The 374s don't *feel* a massive amount superior to 373s in that respect.

 

[Peter Mugridge]

The maths probably also assumed cruising at full speed all the way along the LGV, but this isn't even done with the exiting fleets and schedules on the 186 mph limit - if you monitor the speed with GPS all the way from Calais to Paris, while you're on the LGV it's constantly cycling between about 155 mph and the full 186 mph. It's rare to remain at full line speed for more than about 5 - 10 minutes.

You also have the speed restriction through Lille and around the triangular junction to consider.

There is an element of train performance difference, as mentioned above. The 374s do accelerate a bit better than the 373s.

 

[TRAX]

The maths probably also assumed cruising at full speed all the way along the LGV, but this isn't even done with the exiting fleets and schedules on the 186 mph limit - if you monitor the speed with GPS all the way from Calais to Paris, while you're on the LGV it's constantly cycling between about 155 mph and the full 186 mph. It's rare to remain at full line speed for more than about 5 - 10 minutes.

You’d be surprised at how much gradients make the speed of a train fluctuate at these high speeds. This not being the only cause of the phenomenon you described of course.

 

[Peter Mugridge]

This not being the only cause of the phenomenon you described of course.

I agree. A member of train crew explained it was the effect of the signalling system rippling out to keep the train spacing as even as possible - which is why the variations are more pronounced as you approach Paris and Lille, where the trains in front of you are slowing down.

 

[Ianno87]

The maths probably also assumed cruising at full speed all the way along the LGV, but this isn't even done with the exiting fleets and schedules on the 186 mph limit - if you monitor the speed with GPS all the way from Calais to Paris, while you're on the LGV it's constantly cycling between about 155 mph and the full 186 mph. It's rare to remain at full line speed for more than about 5 - 10 minutes.

You also have the speed restriction through Lille and around the triangular junction to consider.

There is an element of train performance difference, as mentioned above. The 374s do accelerate a bit better than the 373s.

High Speed running times are only based on 95% of theoretical speed for performance recovery purposes. So where 300kph can technically be achieved, you'll actually be scheduled at 285kph.

 

[Peter Kelford]

Hi,

A simple question, perhaps I've missed it somewhere. When the e320 were introduced we were promised 15 minutes quicker London-Paris using the 200mph capability once all the previous rolling stock was withdrawn on that route. This doesn't seem to have happened. Does anyone know why?

No line speeds have not increased.

I do believe it may have something to do with braking/acceleration though (though seeing as Paris-London is non-stop the advantage would be minimal to nil). The truth is that the Velaros were never designed to hugely boost Paris services.

 

[LNW-GW Joint]

It's no different to our "140mph" trains (IC225, Pendolino and 80x).
The train capability is higher than the physical infrastructure and/or signalling system will allow.

 

[TheGrew]

I wonder if the article is assuming LGV Picardie which is in theory supposed to cut 20 minutes off existing times via LGV Nord. I imagine it might be less congested but as it is an unbuilt line I have no idea what linespeed would be.

 

[hexagon789]

300kph is 12 seconds per kilometre.
320kph is 11.25 seconds per kilometre.

It's 200km from the start of LGV Nord at Gonesse to the Fretin Triangle at Lille.

If the whole lot were upgraded, that's a whole 2.5 minutes to be had...

Yeah, I didn't think it would be much so seemingly an element of 'spin' about claimed savings.

I agree. A member of train crew explained it was the effect of the signalling system rippling out to keep the train spacing as even as possible - which is why the variations are more pronounced as you approach Paris and Lille, where the trains in front of you are slowing down.

TVM works in steps rather than giving a constant target speed, the next down from 300 is 270, then 220 and so on.

 

[LSWR Cavalier]

Is significant time to be 'saved' by braking late or braking harder?

 

[hexagon789]

Is significant time to be 'saved' by braking late or braking harder?

TVM effectively ensures drivers brake at a certain level (about 50% iirc), and if they don't meet the braking curve it intervenes with a full service brake application.

 

[Ianno87]

I wonder if the article is assuming LGV Picardie which is in theory supposed to cut 20 minutes off existing times via LGV Nord. I imagine it might be less congested but as it is an unbuilt line I have no idea what linespeed would be.

That would be *incredibly* speculative of Eurostar (I don't think it is a "serious" project at the moment at all - even the 374s would likely be life-expired by the time it comes to fruition), and very disingenuous to claim it as a benefit of the train (so I'd be surprised if that were the basis of the claim).

 

[Peter Kelford]

I wonder if the article is assuming LGV Picardie which is in theory supposed to cut 20 minutes off existing times via LGV Nord. I imagine it might be less congested but as it is an unbuilt line I have no idea what linespeed would be.

It's an unbuilt line with an increasingly reduced business case. That said if the elections are won massively by the EELV it might get built. If it was built at current standards it would be a 320km/h line with provision for 350km/h with ETCS-based signalling on top of TVM. (The standard to which BPL is built).

 

[nlogax]

From the CN report it's seems fairly obvious that the E320 naming was purely a headline to point out they're 200mph capable, but forgetting to mention the obvious practicalities that stop them ever making that sort of speed.

 

[hexagon789]

From the CN report it's seems fairly obvious that the E320 naming was purely a headline to point out they're 200mph capable, but forgetting to mention the obvious practicalities that stop them ever making that sort of speed.

The same could be said of "InterCity 225" they are capable of that speed but certainly practicalities have prevented them regularly running at that speed in service.

 

[Starmill]

The LGV Sud Europe Atlantique line has a max permissible speed of 320 km/h for a good portion of its distance between Tours and Bordeaux. As unlikely as it looks now, if Eurostar were ever to serve Bordeaux it would be theoretically possible for their train sets to exploit their top speed. LGV Est and a small section elsewhere also have the higher maximum permissible speed than the older high speed lines.

 

[Ianno87]

The LGV Atlantique line has a max permissible speed of 320 km/h for a good portion of its distance between Tours and Bordeaux. As unlikely as it looks now, if Eurostar were ever to serve Bordeaux it would be theoretically possible for their train sets to exploit their top speed.

There is a fact a small section of LGV Meditiranée that is 320kph that Marseille services can theoretically use.

 

[Starmill]

There is a fact a small section of LGV Meditiranée that is 320kph that Marseille services can theoretically use.

Ah ha! Is that where that is. I thought I'd heard of it but wasn't sure.

 

[nlogax]

The same could be said of "InterCity 225" they are capable of that speed but certainly practicalities have prevented them regularly running at that speed in service.

Although I do wonder if there was more initial intent by BR to get IC225 to 225 km/h in regular service than there is from Eurostar for E320 to reach 320 km/h.

 

[hexagon789]

There is a fact a small section of LGV Meditiranée that is 320kph that Marseille services can theoretically use.

Do e320s go down that way, though? I thought that was still the preserve of e300s.

 

[Jamesrob637]

Do e320s go down that way, though? I thought that was still the preserve of e300s.

They will do eventually. Whether they will reach 320kmph on said small section though, is another matter.

 

[TRAX]

The LGV Sud Europe Atlantique line has a max permissible speed of 320 km/h for a good portion of its distance between Tours and Bordeaux. As unlikely as it looks now, if Eurostar were ever to serve Bordeaux it would be theoretically possible for their train sets to exploit their top speed. LGV Est and a small section elsewhere also have the higher maximum permissible speed than the older high speed lines.

It would be more than just "theoretically", they will have to run at 320 because that’s the speed the TGVs do on this line (and the other lines cleared for 320).