GWR Class 800

[najaB]

Reason being that planned power upgrades have been shelved. There are also related whispers that VTEC have been asked to look at life extension of their HSTs.

That's surprising - Wikipedia gives the power output of a Class 91 as 4.8 MW, and according to this thread a nine-car Class 801 has a power output of 4MW.

 

[southern442]

That's surprising - Wikipedia gives the power output of a Class 91 as 4.8 MW, and according to this thread a nine-car Class 801 has a power output of 4MW.

I'm rather uneducated on the subject, but it seems to me that it's now becoming accepted that the IEP's aren't as powerful (or as well-designed, for that matter) as their predecessors.

 

[47802]

There are whispers that IEPs might not be authorised to use electric power north of Newcastle or if they are authorised they might be subject to speed and/or power restrictions on that section. Reason being that planned power upgrades have been shelved. There are also related whispers that VTEC have been asked to look at life extension of their HSTs.

Might all be nonsense of course ...

Well bearing in mind the majority of IEP's for the East Coast are electric only that might be a bit tricky then, unless most of those are going to become costly Bi-mode now. Imagine the headlines on that one Electric Trains being replaced by Bi-modes that can only run on Electric as far as Newcastle somehow I don't think so

Of course any life extension to the HST's could be for usage elsewhere, for instance if HST's are retained for the MML they might use East Coast HST's having had greater refurbishment and standardise on MTU Power Cars.

 

[najaB]

I'm rather uneducated on the subject, but it seems to me that it's now becoming accepted that the IEP's aren't as powerful (or as well-designed, for that matter) as their predecessors.

Your "not as powerful" is my "more efficient".

 

[Chris125]

I'm rather uneducated on the subject, but it seems to me that it's now becoming accepted that the IEP's aren't as powerful (or as well-designed, for that matter) as their predecessors.

I don't see how it's 'becoming accepted' that they aren't well designed, based on what? They will no doubt suffer teething troubles just like every other new train design.

 

[Peter Sarf]

Its probably all connected with the, misguided, realisation amongst non-railway decision makers that electrification was not needed anyway .

 

[NotATrainspott]

Even on the bi-mode sets an additional 3 hours of >100mph non-stop diesel running between Edinburgh and Newcastle would be disruptive. Because the IEP was a full-blown design-build-run contract Hitachi have designed absolutely everything for the exact requirements laid out in the contract spec. The bi-mode units, their fuel tanks, the depot fuelling equipment and the diagramming are all perfectly optimised for what should be happening. If diesel sets had to start using their engines north of Newcastle, it would upset everything as trains might no longer be able to carry out the contracted diagrams. Agility Trains would demand compensation in return for the changes they would need to make, just as they did for the Great Western sets.

 

[Clansman]

What's the issue with the line from Newcastle to Edinburgh exactly?

 

[WatcherZero]

I don't see how it's 'becoming accepted' that they aren't well designed, based on what? They will no doubt suffer teething troubles just like every other new train design.

Like the 700's which are currently experiencing an abysmal rate that would be bad even for a 30 year old unrefurbished train. Something like 4,000 MTIN.

 

[gsnedders]

What's the issue with the line from Newcastle to Edinburgh exactly?

Power supply limitations, IIRC.

 

[najaB]

Power supply limitations, IIRC.

But the 800/801's draw less power than class 91's don't they?

 

[gsnedders]

But the 800/801's draw less power than class 91's don't they?

AIUI, yes. Hence, yes, this doesn't make sense. I presume therefore it's something else related to the power supply…

 

[ash39]

Yes, but currently there are a mix of 91's and HST's on VTEC services. When it's all 800/801, they would all be running on electric until Edinburgh which would increase overall load on the power supply, as there could potentially be more electric trains running in each power district at any one time.

Not sure if that is the actual issue they are facing, just a theory of my own.

 

[southern442]

I don't see how it's 'becoming accepted' that they aren't well designed, based on what?

Again, I'm not 100% sure but I did read in Modern Railways a while back that the 800's won't be able to match HST timings from London to Bristol.

 

[LNW-GW Joint]

Yes, but currently there are a mix of 91's and HST's on VTEC services. When it's all 800/801, they would all be running on electric until Edinburgh which would increase overall load on the power supply, as there could potentially be more electric trains running in each power district at any one time.
Not sure if that is the actual issue they are facing, just a theory of my own.

Don't forget TPE will be running 802 bi-modes over that route as well in about 3 years time.

 

[ainsworth74]

Again, I'm not 100% sure but I did read in Modern Railways a while back that the 800's won't be able to match HST timings from London to Bristol.

On diesel. And without uprating the engines. On electric they should be faster and if the engines are used to their maximum capacity then they should be no slower.

It's hardly the fault of the trains that due to the infrastructure not being ready they aren't performing as advertised! If the wires were up and ready and they were now not going to be able to match HST timing that would, of course, be a different matter.

 

[najaB]

Yes, but currently there are a mix of 91's and HST's on VTEC services. When it's all 800/801, they would all be running on electric until Edinburgh which would increase overall load on the power supply, as there could potentially be more electric trains running in each power district at any one time.

Not sure if that is the actual issue they are facing, just a theory of my own.

In which case *some* 800s might need to run in diesel mode, rather than a complete ban. There aren't that many HSTs to Edinburgh so it's surprising that the power supply can't handle it given that as a rough estimate five 800/801 draw about the same as four 91s.

 

[SpacePhoenix]

In which case *some* 800s might need to run in diesel mode, rather than a complete ban. There aren't that many HSTs to Edinburgh so it's surprising that the power supply can't handle it given that as a rough estimate five 800/801 draw about the same as four 91s.

Can they have the engines in a lower rating mode supplementing the available OLE power in that section or is it strictly all diesel or all electric with no option to use a bit of both?

 

[najaB]

Can they have the engines in a lower rating mode supplementing the available OLE power in that section or is it strictly all diesel or all electric with no option to use a bit of both?

I don't know, but suspect not.

 

[ExTankieAaron]

Can they have the engines in a lower rating mode supplementing the available OLE power in that section or is it strictly all diesel or all electric with no option to use a bit of both?

No, our trains are either in electric or diesel mode, not both.
Diesels can be in standby for if you are ready to drop pan but not powering anything.

 

[SpacePhoenix]

Will the engines need uprating for the Edinburgh section to keep to booked times?

 

[jimm]

Will the engines need uprating for the Edinburgh section to keep to booked times?

So a rumour posted on Monday is accepted fact by Wednesday?

 

[CosherB]

Will the engines need uprating for the Edinburgh section to keep to booked times?

Are you having a laugh? :roll:

 

[LNW-GW Joint]

Will the engines need uprating for the Edinburgh section to keep to booked times?

If the OHLE power supply is inadequate, the first resort will be to lower power take-up on electric, not resorting to diesel.
Power restrictions are not unusual on some lines, notably with modern trains on DC sections which have not been upgraded.
I seem to remember the Eurostar class 373s were power-limited on the ECML (that was south of York).

I'm sceptical that 800s will switch diesel power on and off repeatedly (eg Maidenhead-Tilehurst, then on again at Didcot) on the same trip.
Wouldn't you only want to switch once per journey, giving extended periods of diesel/electric running?
Otherwise, why bother to switch diesel off when it will be back on in 20 minutes?
There must be overheads/disadvantages in frequent switching.

TPE will be a rather different proposition with electric at each end and a 50-60 mile diesel gap in the middle (depending on whether wires have reached Stalybridge or not).
I doubt they are going to pan-up for the 2 miles of wiring through Leeds.
I'm also sure someone will be along to disprove all this shortly...

 

[SpacePhoenix]

I'm sceptical that 800s will switch diesel power on and off repeatedly (eg Maidenhead-Tilehurst, then on again at Didcot) on the same trip.
Wouldn't you only want to switch once per journey, giving extended periods of diesel/electric running?
Otherwise, why bother to switch diesel off when it will be back on in 20 minutes?
There must be overheads/disadvantages in frequent switching.

I don't recall seeing any mention of how long it takes to switch between diesel and electric, if it turns out to be measured in minutes rather than seconds then if the electric sections are only around 20mins in length, it might be easier to just leave them in diesel mode

 

[D365]

Have a look at the train technical specification if you want to find out...

 

[LNW-GW Joint]

Have a look at the train technical specification if you want to find out...

If you mean this: (Train Tech Spec 2008, 3.1.2 p13):

TS1577 It is an essential requirement that a bi-mode IEP train shall be capable of switching between modes whilst at any speed from stationary up to line speed.

that does not mean you would choose to switch over short distances.
I don't doubt you can do the actual switching on demand, and at speed.
The question is more of whether you shut down/fire up the diesels for a short stretch of wiring, or simply keep going on diesel.
There can't be any significant cost/performance benefits in doing so, assuming line speed can be reached on diesel.
In any case, that spec may not be the one the DfT signed up to with Agility.
I see there are requirements for parallel electric+diesel operation, but these are "desirable" rather than "essential", so we have no idea if you can actually do that (TS 1962/2000).
Anyway, if NR closes the wiring gap from Maidenhead to Tilehurst before service introduction starts, the situation is moot.

 

[JN114]

If you mean this: (Train Tech Spec 2008, 3.1.2 p13):

that does not mean you would choose to switch over short distances.
I don't doubt you can do the actual switching on demand, and at speed.
The question is more of whether you shut down/fire up the diesels for a short stretch of wiring, or simply keep going on diesel.
There can't be any significant cost/performance benefits in doing so, assuming line speed can be reached on diesel.
In any case, that spec may not be the one the DfT signed up to with Agility.
I see there are requirements for parallel electric+diesel operation, but these are "desirable" rather than "essential", so we have no idea if you can actually do that (TS 1962/2000).
Anyway, if NR closes the wiring gap from Maidenhead to Tilehurst before service introduction starts, the situation is moot.

Service Introduction is Autumn. OHLE goes live in December.

 

[reddragon]

I don't recall seeing any mention of how long it takes to switch between diesel and electric, if it turns out to be measured in minutes rather than seconds then if the electric sections are only around 20mins in length, it might be easier to just leave them in diesel mode

The spec requires that the diesel engines are heated to near operating temperature when not running, to enable instant low stress start-up & full power without an issue.

After about 10 years or so the diesel engines will be replaced by batteries / capacitors anyway!

 

[Clarence Yard]

Service Introduction is Autumn. OHLE goes live in December.

16th October - diesel west from Maidenhead and 2nd January - diesel west from Didcot are the current planning assumptions for IET operation on GWR.

West of Didcot? Who knows. Didcot currently being assumed as a worst case scenario right up until December 2018. Anything better than that will be a bonus. As the units are being timed as HST up to December 2018 there is no effect on the timetable until then.

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