Class 395, why only 140mph?

[Pdf]

I was surprised to find out that the class 395's maximum speed on HS1 is only 140mph. This seems rather low compared to Eurostar's 186mph. Why were the 395s specified for a much lower top speed? It seems a bit silly to invest in a high speed line and then run only one service (Eurostar) at speeds above what the existing mainlines are theoretically capable of (admittedly only in certain stretches, and requiring in cab signalling and maybe tilt capability).

Would journey times be materially improved by using a faster train?
Would using a faster train open more capacity?
Is there ever a problem of Eurostar services getting stuck behind a "slow" southeastern service?
Might we ever see other 140 capable classes (80x, 390, IC225?) running on HS1 if 140mph is all that is expected?

 

[swt_passenger]

Ebbsfleet to St Pancras is not a full high speed line, because it’s almost all in tunnel. So the Eurostar stock only does 140 mph on most of it, and less approaching St Pancras. I suspect there was no real need for the 395s to do higher speeds between Ashford and Ebbsfleet, as they’d be calling at both stations, and the true high speed services are not that frequent so it can all be pathed reliably.

When this was asked before, someone worked out the speed benefits were extremely limited:

Upgrade HS1 domestic for 186mph running speed and introduce 186mph LGV type rolling stock

I think it seems a bit of a let down that a line that's obviously newer than all the existing classic lines is restricted to 140mph considering ones such as the WCML can support speeds of upto 140mph. Assuming the Javelins would be compatible with the loading gauges on our classic lines, why...

www.railforums.co.uk

 

[zwk500]

In brief, the service only runs to 140mph becuase it stops so frequently and the linespeed doesn't get beyond 225kph until most of the services have turned off at Ebbsfleet. Any train simply wouldn't spend enough time above 225kph to make it worth it.:

Would journey times be materially improved by using a faster train?

No, it stops too often

Would using a faster train open more capacity?

No, it stops too often

Is there ever a problem of Eurostar services getting stuck behind a "slow" southeastern service?

It can happen but the timetable is structured to make sure the Eurostars go in front. Approaching London it can be tight, but the speed through the tunnels is slower so the catch up takes longer. All Platforms are on loops on HS1 (and there are additional loops between stations) such that if a Eurostar was right behind a Javelin the signaller could swap them round at the next stop.

Might we ever see other 140 capable classes (80x, 390, IC225?) running on HS1 if 140mph is all that is expected?

80x is potential option, although the 395 is basically an earlier design of 80x (They're both Hitachi A-Train family). Class 390 is unlikely to be worth it as the domestic services sometimes require portion working. IC225 could do it, but Loco-hauled is not good for acceleration which is key to the domestic services.
It's worth pointing out that to work HS1 trains need TVM-430 and some of the French signalling protection systems, which is in-cab signalling but different to ETCS, so even ETCS-fitted trains would need further equipment fitted to work HS1 (or HS1 converted to ETCS).

 

[Mikey C]

The whole point of the 395s is that they're capable of both high speed on HS1 with high acceleration also and then happily run on the 3rd rail classic lines, making them bespoke stock. And with more of a commuter layout inside. No other stock in the country can operate their routes.

 

[plugwash]

Might we ever see other 140 capable classes (80x, 390, IC225?) running on HS1 if 140mph is all that is expected?

The problem is none of the places on hs1 are really massive destinations in their own right. HS1 domestic services only make sense because they run off HS1 onto the classic lines and serve a bunch of places in kent. HS1 is 25KV but the classic lines branching off it at ebsfleet and ashford are third rail.

A class 390 or an intercity 225 can only run under the wires. I guess an 80x could theoretically run such services, but "diesel over the juice" would be a retrograde step.

 

[TT-ONR-NRN]

It’s news to me that Eurostar and SouthEastern even share the same tracks. I thought HS1 was largely four tracked and E* and SE had two each.

 

[Bald Rick]

It’s news to me that Eurostar and SouthEastern even share the same tracks. I thought HS1 was largely four tracked and E* and SE had two each.

wow!

I’ve never heard that theory before!

 

[LNW-GW Joint]

It’s news to me that Eurostar and SouthEastern even share the same tracks. I thought HS1 was largely four tracked and E* and SE had two each.

HS1 is 2-track with passing loops at Lenham and Singlewell, as well as extra tracks at Ashford and Ebbsfleet stations (making it look like a 4-track line briefly).
I can't think of a European HSL which is any different - some allow freight, some don't.
Italy mixes HS and domestic traffic on its older Florence-Rome HSL, otherwise traffic is segregated.
Spain mixes 300km/h and 250km/h trains on its HSLs, where the lower speed trains have tilt and/or gauge changing capability to work onto classic lines.
HS1 does run alongside classic lines in Kent (eg Ashford-Dollands Moor) and Essex, but the only connection is at Ripple Lane (Barking) for freight.

 

[LA50041]

It’s news to me that Eurostar and SouthEastern even share the same tracks. I thought HS1 was largely four tracked and E* and SE had two each.

It's largely a 2 track railway except in Stratford/Ebbsfleet stations

 

[paul1609]

The problem is none of the places on hs1 are really massive destinations in their own right. HS1 domestic services only make sense because they run off HS1 onto the classic lines and serve a bunch of places in kent. HS1 is 25KV but the classic lines branching off it at ebsfleet and ashford are third rail.

A class 390 or an intercity 225 can only run under the wires. I guess an 80x could theoretically run such services, but "diesel over the juice" would be a retrograde step.

In terms of passenger figures I'm afraid thats not really right. Ashford International pre covid had around 4 million exits and entries and just under a million interchanges.
HS1 I would imagine has 90% + of the London traffic now (and the High Speed traffic has recovered much better than the classic lines).
That puts Ashford in around the same category as Preston or Crewe in terms of passenger figures.

 

[43066]

It’s news to me that Eurostar and SouthEastern even share the same tracks. I thought HS1 was largely four tracked and E* and SE had two each.

If you’ve stood at Stratford International watching trains/watched videos shot from
there I can see how you might think that.

Most of it is two track!

 

[paul1609]

If you’ve stood at Stratford International watching trains/watched videos shot from
there I can see how you might think that.

Most of it is two track!

Or St Pancras, Ebbsfleet, Ashford, Westenhanger or Sandgate to be fair.

 

[hexagon789]

I was surprised to find out that the class 395's maximum speed on HS1 is only 140mph. This seems rather low compared to Eurostar's 186mph. Why were the 395s specified for a much lower top speed? It seems a bit silly to invest in a high speed line and then run only one service (Eurostar) at speeds above what the existing mainlines are theoretically capable of (admittedly only in certain stretches, and requiring in cab signalling and maybe tilt capability).

Would journey times be materially improved by using a faster train?
Would using a faster train open more capacity?
Is there ever a problem of Eurostar services getting stuck behind a "slow" southeastern service?
Might we ever see other 140 capable classes (80x, 390, IC225?) running on HS1 if 140mph is all that is expected?

HS1 is 230km/h max until after Southfleet for a start.

It’s news to me that Eurostar and SouthEastern even share the same tracks. I thought HS1 was largely four tracked and E* and SE had two each.

The stations have platform loops but aside from the loops at Singlewell, Lenham Heath and Dollands the route is double track.

 

[TT-ONR-NRN]

If you’ve stood at Stratford International watching trains/watched videos shot from
there I can see how you might think that.

Most of it is two track!

That and also the separate platforms at Ebbsfleet and Ashford, which of course I know are there for a reason, but from a passenger perspective on HS1 it does look a wholly separate operation.

 

[DanNCL]

Might we ever see other 140 capable classes (80x, 390, IC225?) running on HS1 if 140mph is all that is expected?

Definitley not 390s or 91+Mark 4 sets, although the latter was at one point mooted for use on HS1, back in the 80s before either the trains or the route had been built, but ultimately the 373s were built instead. An 80x derivative in the future could be a possibility.

IC225 could do it, but Loco-hauled is not good for acceleration which is key to the domestic services.

I think the gradients on HS1 might be too much for an IC225 unless the DVT was swapped for a second 91.

The problem is none of the places on hs1 are really massive destinations in their own right. HS1 domestic services only make sense because they run off HS1 onto the classic lines and serve a bunch of places in kent. HS1 is 25KV but the classic lines branching off it at ebsfleet and ashford are third rail.

A class 390 or an intercity 225 can only run under the wires. I guess an 80x could theoretically run such services, but "diesel over the juice" would be a retrograde step.

A third rail compatible version of the 80x family could be built should the need for one ever arise.

 

[zwk500]

An 80x derivative in the future could be a possibility.

The 395s are derived from the same family as the 80xs, so in a way they're already running!

I think the gradients on HS1 might be too much for an IC225 unless the DVT was swapped for a second 91.

Depends on the load, but a conventional 200m length destic train would get up the hills. However I agree performance would be inhibited to a big enough extent that they'd never get the timetable slots.

 

[Astro_Orbiter]

The gradients on HS1 are incredible, it's up and down like a rollercoaster

 

[zwk500]

The gradients on HS1 are incredible, it's up and down like a rollercoaster

And the class 91 is a powerful beast, that would have good momentum at 140mph. It wouldn't be as fast as a 395 or 373 by any chalk, but it would make the hill on load 9.

 

[Bald Rick]

The gradients on HS1 are incredible, it's up and down like a rollercoaster

but not for very long. Maximum gradient is 1:40 (2.5%).

 

[py_megapixel]

Does Eurostar actually get up to 186mph on HS1, or is that capability only used on the continental infrastructure?

 

[notadriver]

Between North downs tunnel and Lenham loops. Probably about 5 mins worth.

 

[Jturner98]

I remember someone telling me that the reason 395s can’t travel over 140mph is because of the traction motors and then gearing. If the speed of them was to be increased then the gearing would be changed which would make them accelerate slower. Hence why they went for 140mph. It’s fast enough for HS1, good for acceleration and fast enough to keep out of Eurostars way.

 

[D365]

The 395s are derived from the same family as the 80xs, so in a way they're already running!

"AT300" is arguably just a marketing name, but I'm being facetious.