Do Eurostar trains run at 186mph?

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Wilts Wanderer

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Im speculating but why wouldn’t the TVM display 230kph (or 300kph south of Ebbsfleet for that matter.) Its a display of the maximum speed permitted by the signalling system and route, not the train itself. The driver will regulate his maximum speed against the speedometer, not the TVM display.
 

londonteacher

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I always thought it could be cool to have frequent services to Calais. Make a daytrip so much easier.
Without derailing the thread, I agree. I happen to enjoy Calais and have many times used the Calais Daytripper ticket and the walked from the port into the town. However, Calais doesn't have the appeal of other destinations that the average consumer enjoys so unfortunately will never happen.
 

notadriver

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They are 186mph / 300kph only East of Ebbsfleet (that's where the line speed increases above 140mph, plus the time taken to accelerate - through the gradient down to the Medway viaduct helps with this)
I think actual 300 kph running only happens between the north downs tunnel and the start of the Lenham loops. I reckon 5 minutes worth at most.

This urban myth again...

Trains are timed with 5% recovery, as per standard practice on high speed lines. So the running time is calculated based 140mph running, then inflated by 5% (thus corresponding to ~125mph).

But trains routinely will run at 140mph, either to catch up minor late running, or will just arrive stations slightly early.

Stratford Intl to Ebbsfleet Intl is timed at 10 mins start to stop. You can’t do that at 125 mph max. Also Ashford to Ebbsfleet 18 minutes - standard timing. Impossible at only 125 mph.
 
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Railperf

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I thought it was 225kph to stay consistent with the 140mph conversion. Is the line speed 230 while TVM only displays 225? Not that the 5kph would make much of a difference but can trains get away with running at a few kph over 225 in service?
Believe it or not, Line speed is 230kph for that stretch, and yes, Class 395's get a 225kph indication throughout except the approaches to stations and the approaches to/from the end of HS1 at St Pancras and Ashford. On the press and stakeholders runs we touched 230kph but in normal service drivers are careful to observe the units 225kph maximum service speed. The quite steep and frequent changes in gradient make it difficult to maintain a steady speed. Hence drivers are happy to let speed hover around the 135 to 138mph mark to avoid over speeding downhill.
On the climb out of the Medway Valley the gradient can reduce train speed by as much as 20 kph even on full power.!
 

notadriver

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Im speculating but why wouldn’t the TVM display 230kph (or 300kph south of Ebbsfleet for that matter.) Its a display of the maximum speed permitted by the signalling system and route, not the train itself. The driver will regulate his maximum speed against the speedometer, not the TVM display.

no the TVM display will only display up to the maximum speed for the type of train - not the actual line speed.
 
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Railperf

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no the TVM display will only display the up to the maximum speed for the type of train - not the actual line speed.
I wonder if drivers ever get confused and have ever assumed the speedo is still in kph on the 3rd rail sections? Although to be fair the Javelins are quite slow on 3rd rail and struggle to do more than 90mph.
 

hexagon789

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I wonder if drivers ever get confused and have ever assumed the speedo is still in kph on the 3rd rail sections? Although to be fair the Javelins are quite slow on 3rd rail and struggle to do more than 90mph.
Afaik the speedos say 'mph' or 'km/h' after the actual figure displayed depending on mode presumably to avoid confusion but you'd hope drivers wouldn't get confused to start with!
 

Ianno87

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Stratford Intl to Ebbsfleet Intl is timed at 10 mins start to stop. You can’t do that at 125 mph max. Also Ashford to Ebbsfleet 18 minutes - standard timing. Impossible at only 125 mph.

Ah thanks. Makes me wonder whether "125mph" is somehow reflecting an overall average maximum speed from St Pancras to Ashford, i.e. the higher speed needed east of Stratford is balanced off by the lower attainable speed St Pancras-Stratford.
 

Railperf

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Ah thanks. Makes me wonder whether "125mph" is somehow reflecting an overall average maximum speed from St Pancras to Ashford, i.e. the higher speed needed east of Stratford is balanced off by the lower attainable speed St Pancras-Stratford.
No. It is almost impossible to achieve a 125mph average speed on the fastest section alone from Stratford to Ashford - even excluding the Ebbsfleet stop -
Fastest average speed achieved so far is 119mph on a service train.
 

Ianno87

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No. It is almost impossible to achieve a 125mph average speed on the fastest section alone from Stratford to Ashford - even excluding the Ebbsfleet stop -
Fastest average speed achieved so far is 119mph on a service train.

No, I meant as in take the average of:
1. Maximum speed needed to meet the timetable St Pancras-Stratford
2. Maximum speed needed to meet the timetable Stratford-Ebbsfleet
3. Maximum speed needed to meet the timetable Ebbsfleet-Ashford

Trying to source a rational explanation for "125mph", other than a simplistic off the cuff number punted by a journalist in 2009 (which is probably more likely)
 

Railperf

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No, I meant as in take the average of:
1. Maximum speed needed to meet the timetable St Pancras-Stratford
2. Maximum speed needed to meet the timetable Stratford-Ebbsfleet
3. Maximum speed needed to meet the timetable Ebbsfleet-Ashford

Trying to source a rational explanation for "125mph", other than a simplistic off the cuff number punted by a journalist in 2009 (which is probably more likely)
It doesn't really matter. As explained by @notadriver the maximum achievable speed between St Pancras and Stratford is around 105mph. From Stratford to Ebbsfleet and between Ebbsfleet and Ashford trains will reach a maximum 140 mph..but the demanding gradients mean speed varies quite significantly with lows of around 125mph at the highest summits.
So maybe 125mph was quoted as the normal 'minimum speed on the open stretches of track. Eurostar trains will reach 186mph but again the speeds are variable on gradients.
Eurostar schedules are quite generous and it is not unknown to trundle through Kent at no more than 140mph and still arrive at the Eurotunnel portal on time.

In fact it appears Southeastern trains are given priority and an early running Eurostar can be regulated to remain in its path - depending on the signaller in charge.
 

AverageTD

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Believe it or not, Line speed is 230kph for that stretch, and yes, Class 395's get a 225kph indication throughout except the approaches to stations and the approaches to/from the end of HS1 at St Pancras and Ashford. On the press and stakeholders runs we touched 230kph but in normal service drivers are careful to observe the units 225kph maximum service speed. The quite steep and frequent changes in gradient make it difficult to maintain a steady speed. Hence drivers are happy to let speed hover around the 135 to 138mph mark to avoid over speeding downhill.
On the climb out of the Medway Valley the gradient can reduce train speed by as much as 20 kph even on full power.!
Thanks for clearing that up! Does this mean that ES drivers get 230kp/h on their TVM as far as Ebbsfleet?
 

LNW-GW Joint

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HS1 (and HS2) are signed in metric and managed by TVM/ETCS so it's 230km/h whatever the imperial conversion is.
230km/h is a very common top speed in Europe when the full high speed (300/320km/h) is not available, eg on German and Austrian upgraded lines.
Just as the Cambrian is 120/130km/h (mostly), or 90km/h on the coast.
 

Railperf

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Thanks for clearing that up! Does this mean that ES drivers get 230kp/h on their TVM as far as Ebbsfleet?
Yes, except when stopping in the platforms - where lower limits apply. Plus the start and approach to and from St Pancras has lower limits for a while.
 

notadriver

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Thanks for clearing that up! Does this mean that ES drivers get 230kp/h on their TVM as far as Ebbsfleet?

Javelins in service always have to call at Stratford so they are never able to reach 225 kph in the London tunnels leaving St Pancras
 

Wilts Wanderer

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I remember reading a while back that if a 373 was set on the cruise control at 186mph the actual speed would vary as low as 155mph depending on the gradients, if a skilled driver was powering it manually and maintaining close to linespeed a full 10 minutes can be saved between Calais and Paris, or made up if running late. It would be interesting to know more about SNCF driving techniques - various online cab view videos show the current speed and some drivers definitely seem to coast over gradients and avoid using the brakes, at the cost of losing speed uphill. Presumably if the schedules are designed to allow it, it saves on component wear and power.
 

Railperf

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I remember reading a while back that if a 373 was set on the cruise control at 186mph the actual speed would vary as low as 155mph depending on the gradients, if a skilled driver was powering it manually and maintaining close to linespeed a full 10 minutes can be saved between Calais and Paris, or made up if running late. It would be interesting to know more about SNCF driving techniques - various online cab view videos show the current speed and some drivers definitely seem to coast over gradients and avoid using the brakes, at the cost of losing speed uphill. Presumably if the schedules are designed to allow it, it saves on component wear and power.
French TGV-SE PAris - Lyon schedule was designed for full power application for just 1/3 of the 264 mile journey and using the kinetic energy of the train to coast over the gradients like a roller coaster

By 1 or 2mph (i.e. 187mph in UK, 185mph in France).
Speeds can fluctuate wildly so a few kph over or under isn't an issue. The TVM signalling will cut in if 10 kph over the posted limit, So 310kph on 300kph track. 240kph on 230kph track etc.

Using the term 'trundle' here very lightly :lol:
Yes, the sound insulation is so good, and HS track so smooth that 140mph can feel like less than 70mph on a normal train! Certainly a class 153 at 60mph is noisier and bouncier!

I remember reading a while back that if a 373 was set on the cruise control at 186mph the actual speed would vary as low as 155mph depending on the gradients,
From 186mph, speed can drop to 168mph from Medway bridge up to North Downs tunnel - but not sure full power is used uphill!
 

Ianno87

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I remember reading a while back that if a 373 was set on the cruise control at 186mph the actual speed would vary as low as 155mph depending on the gradients, if a skilled driver was powering it manually and maintaining close to linespeed a full 10 minutes can be saved between Calais and Paris, or made up if running late. It would be interesting to know more about SNCF driving techniques - various online cab view videos show the current speed and some drivers definitely seem to coast over gradients and avoid using the brakes, at the cost of losing speed uphill. Presumably if the schedules are designed to allow it, it saves on component wear and power.

Amongst other things, it is quite a demanding mental workload on the driver to keep powering off and on to "hug" the line speed profile for long sustained runs - I can see why cruise control is attractive in managing this.
 

Railperf

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Amongst other things, it is quite a demanding mental workload on the driver to keep powering off and on to "hug" the line speed profile for long sustained runs - I can see why cruise control is attractive in managing this.
The London to Paris path intersects with Eurotunnel and then the main Paris to Brussels TGV line. There are several mins allowance on the St Pancras to Eurotunnel UK portal to ensure Eurostar hits its Eurotunnel slot in case of any slight delay. The same applies between Calais and Lille Fretin Junction to ensure that the Paris - Lille path can be achieved.
 

hexagon789

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Speeds can fluctuate wildly so a few kph over or under isn't an issue. The TVM signalling will cut in if 10 kph over the posted limit, So 310kph on 300kph track. 240kph on 230kph track etc.
I understood it was a 15km/h tolerance at over 160km/h?

I remember reading a while back that if a 373 was set on the cruise control at 186mph the actual speed would vary as low as 155mph depending on the gradients, if a skilled driver was powering it manually and maintaining close to linespeed a full 10 minutes can be saved between Calais and Paris, or made up if running late. It would be interesting to know more about SNCF driving techniques - various online cab view videos show the current speed and some drivers definitely seem to coast over gradients and avoid using the brakes, at the cost of losing speed uphill. Presumably if the schedules are designed to allow it, it saves on component wear and power.
Coasting where practical is very much routine, plus the French go very much for 'defensive' driving I understand. Any whiff of a cautionary signal aspect and on come the brakes. I seem to recall reading this caused issues when the Eurostars first started running - UK drivers were used to running at speed on double yellows whereas the French drivers would kill the speed off too much and lose time until they got into the habit of driving less cautiously under UK signalling where braking distances for signals are a lot more variable.
 

Wilts Wanderer

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I understood it was a 15km/h tolerance at over 160km/h?


Coasting where practical is very much routine, plus the French go very much for 'defensive' driving I understand. Any whiff of a cautionary signal aspect and on come the brakes. I seem to recall reading this caused issues when the Eurostars first started running - UK drivers were used to running at speed on double yellows whereas the French drivers would kill the speed off too much and lose time until they got into the habit of driving less cautiously under UK signalling where braking distances for signals are a lot more variable.

That’s understandable, given that French railway signalling is based on speed principles (as opposed to route-based UK signalling.) Running at linespeed on anything other than the least restrictive aspect is anathema so I imagine that braking reflex is deeply ingrained in a professional driver.
 

hexagon789

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That’s understandable, given that French railway signalling is based on speed principles (as opposed to route-based UK signalling.) Running at linespeed on anything other than the least restrictive aspect is anathema so I imagine that braking reflex is deeply ingrained in a professional driver.
I suppose it would be thinking about it, because you would always need to brake under cautionary aspects because of the standard braking distances. I've always thought of French signalling as more a sort of hybrid of route and speed signalling as route indications are given at junctions in addition to the permissible speed unlike most other pure speed signalling systems where you just get the relevant speed indication
 

LNW-GW Joint

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I understood it was a 15km/h tolerance at over 160km/h?
Coasting where practical is very much routine, plus the French go very much for 'defensive' driving I understand. Any whiff of a cautionary signal aspect and on come the brakes. I seem to recall reading this caused issues when the Eurostars first started running - UK drivers were used to running at speed on double yellows whereas the French drivers would kill the speed off too much and lose time until they got into the habit of driving less cautiously under UK signalling where braking distances for signals are a lot more variable.
That might have been the case when classic UK infrastructure was in use, but it's now TVM pretty much throughout, with standardised signal spacing.
I'd have thought ES would simply drive to whatever speed TVM tells them is authorised.
There won't be many double yellows between Paris (Gonesse) and London (St Pancras approaches).
 

Ianno87

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That might have been the case when classic UK infrastructure was in use, but it's now TVM pretty much throughout, with standardised signal spacing.
I'd have thought ES would simply drive to whatever speed TVM tells them is authorised.
There won't be many double yellows between Paris (Gonesse) and London (St Pancras approaches).

I may be making this up, but for customs reasons, isn't it the case that drivers of Eurostar services should avoid stopping completely outside stations without international facilities as far as is practicable?

Therefore when a restrictive TVM indication is received, drivers would "hang back" to avoid being brought to a stop completely, where this is practical, and generally avoid excessive early running.
 

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