AT300 journey time improvements

Status
Not open for further replies.

TheWalrus

Established Member
Joined
6 Oct 2008
Messages
1,843
Location
Exeter
Reading the recent news the FGW are likely to be receiving new trains for London-West services, they are expected to reduce journey times by 5 minutes to Exeter, 6 to Plymouth and 14 to Penzance. This seems a relatively small reduction compared to those to Oxford, Bristol and South Wales. For example, a document I read about IEP said the new trains would reduce journey times by 4 to Reading and 6 to Oxford. So does this mean they will only save 2 minutes between Reading and Plymouth? Which is the same as they will save between Reading and Oxford which is a lot shorter distance?

To me it seems the AT300s should be cutting journey times down a lot more west of Reading? Or is it to do with lower line speeds?

Mods' note: This thread is JUST for discussing AT300 journey time improvements (or lack of!). Any other discussion, such as catering matters, Driver Only Operation (with travelling ticket inspector) matters, comparisons with HSTs or any other subject matter must go in a separate thread (existing if there is one, or new if there isn't).
 
Last edited by a moderator:
Sponsor Post - registered members do not see these adverts; click here to register, or click here to log in
R

RailUK Forums

Robbies

Established Member
Joined
20 Sep 2009
Messages
2,305
Location
East Sussex
I believe the maximum speed of IEP/AT300 with diesel is 100mph where as it is 125mph plus under the wires. It would be interesting to compare acceleration times between the IEP and IC125. I am presuming perhaps wrongly that since there is some time saving that the acceleration time is quicker with the IEP?
 

Muzer

Established Member
Joined
3 Feb 2012
Messages
2,754
I was under the impression it was 110mph rather than 100mph. But how much is cleared for 125mph that won't be electrified?
 

LNW-GW Joint

Veteran Member
Joined
22 Feb 2011
Messages
15,505
Location
Mold, Clwyd
I believe the maximum speed of IEP/AT300 with diesel is 100mph where as it is 125mph plus under the wires. It would be interesting to compare acceleration times between the IEP and IC125. I am presuming perhaps wrongly that since there is some time saving that the acceleration time is quicker with the IEP?

Roger Ford says on his Twitter feed (June 10) that the DfT has confirmed 125mph as the IEP maximum speed on diesel only.
The parliamentary written answer by Claire Perry I have seen doesn't say that, it says:
The new train fleet will have appropriate performance characteristics to operate on the far South West routes
which is about as weaselly as you can get.
 

al.currie93

Member
Joined
27 Jun 2013
Messages
381
I believe the maximum speed of IEP/AT300 with diesel is 100mph where as it is 125mph plus under the wires. It would be interesting to compare acceleration times between the IEP and IC125. I am presuming perhaps wrongly that since there is some time saving that the acceleration time is quicker with the IEP?

The acceleration will be greater with the AT300s without a doubt, due to more modern components, being multiple units as opposed to locomotive hauled trains and also being directly electrically powered in places. I reckon that this greater acceleration will probably be the only thing that yields quicker journey times. However, how much greater that acceleration will be is yet to be determined, and if those journey time decreases are correct then the greater acceleration doesn't actually seem to be counting for much.
 

The Planner

Veteran Member
Joined
15 Apr 2008
Messages
11,206
Depends on the amount of stops, you will hit a ceiling with acceleration anyway due to professional driving and comfort levels. A lot of current stock could be faster off the blocks if required.
 

Class83

Member
Joined
8 Jun 2012
Messages
411
There isn't any >100mph running north of Edinburgh and I suspect there is little west of Exeter. What's probably more important is their ability to stay at line limits of 70-100mph up inclines for the Highland Mainline and Devon as well as acceleration.
 

TheWalrus

Established Member
Joined
6 Oct 2008
Messages
1,843
Location
Exeter
There isn't any >100mph running north of Edinburgh and I suspect there is little west of Exeter. What's probably more important is their ability to stay at line limits of 70-100mph up inclines for the Highland Mainline and Devon as well as acceleration.

Apparently Exeter-Plymouth will only be a minute quicker so not even much difference there.
 

class26

Member
Joined
4 May 2011
Messages
906
There isn't any >100mph running north of Edinburgh and I suspect there is little west of Exeter. What's probably more important is their ability to stay at line limits of 70-100mph up inclines for the Highland Mainline and Devon as well as acceleration.

But there is some 110 mph running currently west of Newbury.

It depends who is correct. Roger Ford states 125 mph with diesel but the Hitachi web site say only 100 mph. Can anyone clear this up ?
 

NotATrainspott

Established Member
Joined
2 Feb 2013
Messages
3,082
Could it be that just as the bi-mode IEPs have a limiter on their diesel power-packs, Hitachi would limit their top speed on diesel to reduce maintenance requirements on routes that don't need it? 200km/h capability on diesel is nice and all but as others have said, on the routes the trains will run it is not going to be necessary unless there's a power failure on the electrified mainline, at which point there are more pressing issues to deal with.
 

D6975

Established Member
Joined
26 Nov 2009
Messages
2,267
Location
Bristol
The Hitachi website doesn't say that they will be 100 mph.
What it says is : quote

The AT300 trains are a train platform developed by Hitachi Rail. Their most famous relatives in the UK are the Class 395 Javelin™ train currently in service in Kent and the Class 800/801 train for the Intercity Express Programme. This family of trains is designed for intercity travel, with speeds of up to 140 mph for the Class 395 Javelin and 125 mph for the Class 800/801 trains for electric operation and 100 mph for bi-mode operation. The Class AT300 has larger fuel tanks than the Class 800 bi-mode trains and engines that operate at a higher power output.

Read that properly and you will see that the 100mph refers to the first Bi-mode order. The second (WOE) Bi-mode order has larger fuel tanks and more powerful engines. The top speed is not specified.
 

Martin222002

Member
Joined
6 Nov 2011
Messages
238
Location
Chesterfield, Derbyshire
But there is some 110 mph running currently west of Newbury.

It depends who is correct. Roger Ford states 125 mph with diesel but the Hitachi web site say only 100 mph. Can anyone clear this up ?

As has been said the confusion started after Claire Perry answered two parliamentary written questions which implied that the IEP 800s would run at 125mph on diesel. This of course conflicted what Hitachi had stated on its website, as linked above, that they would only do 100mph on diesel.

Roger Ford has been trying clarify this, and the DfT seems to be adamant that the IEP 800s will do 125mph on diesel. So if this really is the case then the AT300s for the south west 'should' do 125mph on diesel too.
 

D365

Established Member
Joined
29 Jun 2012
Messages
8,331
The second (WOE) Bi-mode order has larger fuel tanks and more powerful engines. The top speed is not specified.

They use the same power packs, it's never been said otherwise - merely that those in the Class 800 are don't use the full power output in normal service...:roll:

But yes, there is clarification needed regarding top speed for the Class 800 or the enhanced AT300 when running self-powered.
 

47802

On Moderation
Joined
8 Oct 2013
Messages
3,455
The specification regarding the AT-300 for the South West may well be different to IEP regarding Top Speed, as there is no real need for the IEP to go above 100mph on Diesel in normal operation.
 

Noddy

Member
Joined
11 Oct 2014
Messages
378
Location
UK
Reading the recent news the FGW are likely to be receiving new trains for London-West services, they are expected to reduce journey times by 5 minutes to Exeter, 6 to Plymouth and 14 to Penzance. This seems a relatively small reduction compared to those to Oxford, Bristol and South Wales. For example, a document I read about IEP said the new trains would reduce journey times by 4 to Reading and 6 to Oxford. So does this mean they will only save 2 minutes between Reading and Plymouth? Which is the same as they will save between Reading and Oxford which is a lot shorter distance?

To me it seems the AT300s should be cutting journey times down a lot more west of Reading? Or is it to do with lower line speeds?

OK so let me get this right. The difference between Paddington and Reading is 4min (at up to 125) and the difference between Reading and Exeter is only 1min (at 125 to Newbury, ?100 beyond?). So I would presume that 1min gain is under electric to Newbury - and there no gain beyond. Surely not?

Would it be better to allow maximum speed beyond Newbury (ie 125/110) even if the 100+ sections are short as the quicker acceleration and braking of the IEPs/AT300s will allow them to run at 110/125 for longer. Thus gaining a further advantage over an HST? Or is there no significant acceleration/braking gain on diesel mode? There seem to be more questions than answers?!
 
Last edited:

notadriver

Established Member
Joined
1 Oct 2010
Messages
3,388
Depends on the amount of stops, you will hit a ceiling with acceleration anyway due to professional driving and comfort levels. A lot of current stock could be faster off the blocks if required.

Which stock specifically ?
--- old post above --- --- new post below ---
The acceleration will be greater with the AT300s without a doubt, due to more modern components, being multiple units as opposed to locomotive hauled trains and also being directly electrically powered in places. I reckon that this greater acceleration will probably be the only thing that yields quicker journey times. However, how much greater that acceleration will be is yet to be determined, and if those journey time decreases are correct then the greater acceleration doesn't actually seem to be counting for much.

The other factor that may also decrease journey times is dwell times. Power operated doors with SDO controlled by the driver could save loads compared with an HST.
 

LNW-GW Joint

Veteran Member
Joined
22 Feb 2011
Messages
15,505
Location
Mold, Clwyd
OK so let me get this right. The difference between Paddington and Reading is 4min (at up to 125) and the difference between Reading and Exeter is only 1min (at 125 to Newbury, ?100 beyond?). So I would presume that 1min gain is under electric to Newbury - and there no gain beyond. Surely not?

Would it be better to allow maximum speed beyond Newbury (ie 125/110) even if the 100+ sections are short as the quicker acceleration and braking of the IEPs/AT300s will allow them to run at 110/125 for longer. Thus gaining a further advantage over an HST? Or is there no significant acceleration/braking gain on diesel mode? There seem to be more questions than answers?!

Nothing above 110mph after Reading via Newbury (and not much above 100mph).
 

TheWalrus

Established Member
Joined
6 Oct 2008
Messages
1,843
Location
Exeter
OK so let me get this right. The difference between Paddington and Reading is 4min (at up to 125) and the difference between Reading and Exeter is only 1min (at 125 to Newbury, ?100 beyond?). So I would presume that 1min gain is under electric to Newbury - and there no gain beyond. Surely not?

Would it be better to allow maximum speed beyond Newbury (ie 125/110) even if the 100+ sections are short as the quicker acceleration and braking of the IEPs/AT300s will allow them to run at 110/125 for longer. Thus gaining a further advantage over an HST? Or is there no significant acceleration/braking gain on diesel mode? There seem to be more questions than answers?!

Doesn't seem right when for example the Cotswolds services will get to
Worcester in 2 hours, most of which is under bi-mode.
--- old post above --- --- new post below ---
Which stock specifically ?
--- old post above --- --- new post below ---


The other factor that may also decrease journey times is dwell times. Power operated doors with SDO controlled by the driver could save loads compared with an HST.

However it's unlikely dwell times will be cut under two minutes at Reading, Taunton, Exeter or Plymouth.
 

Woody

Member
Joined
10 Dec 2006
Messages
277
Doesn't seem right when for example the Cotswolds services will get to
Worcester in 2 hours, most of which is under bi-mode.
--- old post above --- --- new post below ---


However it's unlikely dwell times will be cut under two minutes at Reading, Taunton, Exeter or Plymouth.

Both the AT300 and Bi-mode IEP are both powered by the same MTU 700kW Vee12 1600R80L diesel engine. The only difference is that the 5 car class 800 bi-mode IEP is effectively overpowered for contractual penalty reasons to allow for the lost of one engine in service whereas a 5 car AT300 will require the full 700kW output to keep to time on the Devon and Cornwall banks and of course bigger fuel tanks. So rather than the AT300 engines being up rated the IEP engines are down rated. Therefore based on power to weight ratio and the maximum 700kW engine output the AT300 has a slight performance edge on a 2+8 IC125 of 11.30hp per ton compared to an IC125s 10.77hp per ton. So the AT300s performance on diesel should be comparable to an IC125 beyond the end of the wires at Newbury and superior on electric power between Paddington and Newbury. Hence journey time reductions of only 5 minutes to Exeter and 6 minutes to Plymouth. Even if electrification is eventually extended into the south west I doubt whether even an all electric AT300 could improve on existing "Voyager" 15hp per ton timings on the speed restricted Devon and Cornwall banks.
 

The Planner

Veteran Member
Joined
15 Apr 2008
Messages
11,206
Which stock specifically ?

Pendo's for a start, I would expect HSTs to also be quicker off the blocks without professional driving too.
--- old post above --- --- new post below ---
The other factor that may also decrease journey times is dwell times. Power operated doors with SDO controlled by the driver could save loads compared with an HST.

I doubt they will get much below 1½ minutes, standard HST dwell is 2 and 1½ at specific stations.
 

D6975

Established Member
Joined
26 Nov 2009
Messages
2,267
Location
Bristol
Nothing above 110mph after Reading via Newbury (and not much above 100mph).

And once you hit the sea wall in Devon, it's mostly 60 mph all the way to Penzance. There are stretches of 65 and 70 here and there, but they aren't very long, most of them are sub 5 miles in length and some of them are through stations where all services stop.
 

AM9

Established Member
Joined
13 May 2014
Messages
9,543
Location
St Albans
And once you hit the sea wall in Devon, it's mostly 60 mph all the way to Penzance. There are stretches of 65 and 70 here and there, but they aren't very long, most of them are sub 5 miles in length and some of them are through stations where all services stop.

Wouldn't that tend increasingly to limit the extent of through services in the future? A train designed to do 125/100 through to Exeter is fine but the roller-coaster journey over the banks beyond would be better served by capable 75mph-geared stock.
 

D6975

Established Member
Joined
26 Nov 2009
Messages
2,267
Location
Bristol
PLY-PNZ is currently typically timed at 2 hours, for a journey of just under 80 miles. It's not the motive power that is the limitation, but the sinuous nature of the route. Significant reduction of journey time is only going to come with very expensive realignment of the route.
 

class26

Member
Joined
4 May 2011
Messages
906
PLY-PNZ is currently typically timed at 2 hours, for a journey of just under 80 miles. It's not the motive power that is the limitation, but the sinuous nature of the route. Significant reduction of journey time is only going to come with very expensive realignment of the route.

It`s also the signalling which is being replaced over the next 5 years and we are told this will help cut journey times between Plymouth and Penzance but not how. My guess is that it will enable more services so stopping trains will enable the "express" services to miss out more stations and so refduce through journey times

Incidentally there is some 80 mph after Dawlish and some 75 MPH in Cornwall, nearer to Penzance but it is true that generally speeds in Cornwall are around the 60 - 65 mph mark
 

Woody

Member
Joined
10 Dec 2006
Messages
277
PLY-PNZ is currently typically timed at 2 hours, for a journey of just under 80 miles. It's not the motive power that is the limitation, but the sinuous nature of the route. Significant reduction of journey time is only going to come with very expensive realignment of the route.

Knocking the largest conurbation and economy west of Bristol, Plymouth 300k, and indeed Cornwall off FGWs so called high speed rail network would I suspect cause more than a few political problems for the government now that SW is almost totally blue except for Exeter. Until the growing historical mismatch between modern train capability and infrastructure west of Exeter is sorted nothing much is going to happen railway wise in this part of the world. Back in 1939 only the war stopped the building of a new much straighter Dawlish avoiding line https://en.wikipedia.org/wiki/Dawlish_Avoiding_Line together with a new route westward from Newton Abbot to a point near Marley Tunnel (A38 dual carriageway) bypassing Dainton/Totnes/Rattery bank which was also surveyed at the same time. Both schemes were engineered to a minimum one mile radius curvature for speed. However today we are effectively stuck with little more than Victorian line speeds in South Devon and Cornwall. Of course nothing will ever happen now for cost and political reason. Moving long distance traffic away from the current coastal route via Dawlish would leave it financially exposed carrying at best marginal local and seasonal traffic. It seems to be the classic case of "damned if you do and damned if you don't" which is why Plymouth is now pushing to get its airport reopened.
http://www.plymouthherald.co.uk/Pla...port-smashes/story-26602140-detail/story.html
 

LexyBoy

Established Member
Fares Advisor
Joined
23 Jan 2009
Messages
4,472
Location
North of the rivers
Knocking the largest conurbation and economy west of Bristol, Plymouth 300k, and indeed Cornwall off FGWs so called high speed rail network [...]

I don't think anyone's seriously suggesting that! (And in any case it wouldn't make much difference as noted above). Something more suitable than a 150 would be nice for the PNZ-PLY/EXD services though.

Also, with pedant mode engaged, I can think of many larger conurbations in Britain west of Bristol - Cardiff, Liverpool, Edinburgh and Glasgow for starters...
 

D6975

Established Member
Joined
26 Nov 2009
Messages
2,267
Location
Bristol
Yes there is a bit of 80mph along the sea wall, but how often is it that there isn't a temporary speed restriction somewhere along the wall? There always seems to be one somewhere when I'm down that way.
What I find peculiar is that the speed restriction of 70 mph on the approach to Penzance in the sectional appendix seems to run to just short of the platforms, then suddenly drops to 15 (or is it 25) for the last bit over the pointwork into the platforms. You'd have thought a drop to 40 or so near Marazion westbound would be a sensible idea. I wouldn't want to be on a HST going past Long Rock at 70. Good job the drivers know what they're doing...
 

The Planner

Veteran Member
Joined
15 Apr 2008
Messages
11,206
Its a speed limit based on the infrastructure, doesn't mean it can be achieved or has to be attained.
 
Status
Not open for further replies.

Top