GWR Class 800

[LNW-GW Joint]

Roger Ford says in March Modern Railways (p30) that acceptance of the first class 800 has slipped from 2 February to 17 May.
Apparently there are still issues with electrical interference on the Tilehurst-Didcot test section of Series 1 OHLE.
The DfT has also contracted full power (700kW rather than 560kW) on the GWR IEPs, to maintain current HST running times.

 

[Peter Sarf]

Hmmmmm. watch out, here comes reality.

On a positive note the engines can of course be de-rated, in the future, as more electrification comes on stream. Thus providing an incentive for electrification to continue allowing better reliability and fuel savings.

 

[Envoy]

Roger Ford says in March Modern Railways (p30) that acceptance of the first class 800 has slipped from 2 February to 17 May.
Apparently there are still issues with electrical interference on the Tilehurst-Didcot test section of Series 1 OHLE.
.

I presume this refers to elect-magnetic fields interfering with signalling equipment? That being so, do such electro-magnetic fields pose a danger to human health - be it passengers or residences near tracks?

 

[ainsworth74]

Have you kept the TTS bookmarked all these years?!

I just Google it every time I need it so not that bad

That being said I've referred to it so often that I think I'm starting to memorise parts of it...

 

[najaB]

I presume this refers to elect-magnetic fields interfering with signalling equipment? That being so, do such electro-magnetic fields pose a danger to human health - be it passengers or residences near tracks?

I doubt it very much. The intensity of an EM field that can induce a stray current in a long length of wire is significantly less than that required to produce ill-effects in a living being.

 

[SpacePhoenix]

Does Tilehurst-Didcot use track circuits or axle counters for train detection?

 

[ainsworth74]

I doubt it very much. The intensity of an EM field that can induce a stray current in a long length of wire is significantly less than that required to produce ill-effects in a living being.

Plus isn't it an issue with the interaction of the train and the auto-transformer on the OLE rather than the signalling (with emphasis on it being an OLE problem not a rolling stock problem)? I'm sure I've read that somewhere or other.

 

[najaB]

Plus isn't it an issue with the interaction of the train and the auto-transformer on the OLE rather than the signalling (with emphasis on it being an OLE problem not a rolling stock problem)? I'm sure I've read that somewhere or other.

Quite possibly. I've not seen it explained properly and that makes more sense than a signalling issue.

 

[snowball]

Roger Ford says in March Modern Railways (p30) that acceptance of the first class 800 has slipped from 2 February to 17 May.

Just to clarify, that slippage in the target date is recognised as due to late delivery of the test track.

 

[WatcherZero]

Could plausibly be the autotransformer or the signalling all I know is its an interference issue that's present on the GWML but not present on the ECML.

 

[swt_passenger]

Could plausibly be the autotransformer or the signalling all I know is its an interference issue that's present on the GWML but not present on the ECML.

From the February Modern Railways, page 34:

"So what is the problem?

...an imbalance within the two traction circuits in the nine-car test unit generated 'spikes' which affected the traction current supply causing tripping. It is worth noting that similar problems were reported when the Class 390 Pendolinos first began running on the WCML. The solution is relatively simple."

I don't think it has been copied here before, but RF's explanation seems to rule out signalling.

 

[800001]

800002 and 800005 (first uk assembled unit), passed Darlington at 17:18 this evening working from Merchant Park - Doncaster IEP depot.

 

[spark001uk]

Could plausibly be the autotransformer or the signalling all I know is its an interference issue that's present on the GWML but not present on the ECML.

From the February Modern Railways, page 34:

Quote:
"So what is the problem?

...an imbalance within the two traction circuits in the nine-car test unit generated 'spikes' which affected the traction current supply causing tripping.

I don't think it has been copied here before, but RF's explanation seems to rule out signalling.

Surely that also suggests the problem is present on the ECML, as that's the only place the 9-car has been tested isn't it?

 

[najaB]

Surely that also suggests the problem is present on the ECML, as that's the only place the 9-car has been tested isn't it?

They would've been tested at Old Dalby before the mainline, would they not?

And this nine-car set appears to be running in electric mode when it leaves Newcastle.

[youtube]mVE6L1lNX1o[/youtube]

 

[LNW-GW Joint]

Surely that also suggests the problem is present on the ECML, as that's the only place the 9-car has been tested isn't it?

No, the comments referred specifically to tests on the RS3 (Tilehurst-Didcot) test section at the end of September last year.
The ECML doesn't have autotransformer functionality (parts of the WCML do).
Also, nobody yet runs above 110mph with multiple pantographs.

 

[najaB]

The ECML doesn't have autotransformer functionality (parts of the WCML do).

I thought that was going in as part of the power supply strengthening work that's underway at present?

 

[LNW-GW Joint]

I thought that was going in as part of the power supply strengthening work that's underway at present?

I believe it is but I don't think it's operational yet.

 

[Dave1987]

So there is another variation order going in and yet more cost. But the DFT aren't paying so they probably don't care. And it would seem RF's figures were correct, thought you had 'disproven' them D1009!

 

[455driver]

Very true that is 40% - 44.5% of the unit with no engine. Well a bit better, perhaps 45% - 50% of seats in coaches with no engine. That is because the driving coaches have less seats in.

The driving coaches (with less seats) are 2 of the ones witout engines so your maths is slewed the wrong way, its about 30%-40% seats in coaches with no engines.

 

[455driver]

Might be quieter inside though!

They are a lot quieter than a Voyager, I mean seriously quieter.

 

[LNW-GW Joint]

But the DFT aren't paying so they probably don't care.

They are, because the extra cost to GWR will be deducted from its premium payments to DfT...

 

[leomartin125]

Last night 800002 took 800005 to it's new home at North Pole IEP Depot, via Doncaster Carr IEP Depot from Merchant Park Sidings.

Here is the working:

http://www.realtimetrains.co.uk/train/K97167/2017/02/24/advanced

 

[ainsworth74]

So there is another variation order going in and yet more cost.

What variation order?

 

[FGW_DID]

Does Tilehurst-Didcot use track circuits or axle counters for train detection?

Axle counters, not 100% about Didcot but definitely at the Tilehurst end, it was multiple axle counter failures at Pangbourne that curtailed one of the recent 800 test runs.

 

[JN114]

Axle counters, not 100% about Didcot but definitely at the Tilehurst end, it was multiple axle counter failures at Pangbourne that curtailed one of the recent 800 test runs.

Didcot area is Axle Counters as of Christmas just gone

 

[Master29]

They are, because the extra cost to GWR will be deducted from its premium payments to DfT...

What does it matter. Still the taxpayer at the end of the day.

 

[43074]

So there is another variation order going in and yet more cost. But the DFT aren't paying so they probably don't care. And it would seem RF's figures were correct, thought you had 'disproven' them D1009!

There's no extra variation order for this, the variation order was for the engines being fitted in the first place, the extra cost that this will incur will be in fuel and maintenance for running the engines at their full 700kW rating. AIUI the depots haven't been designed to provide the diesel engines with the extra maintenance the trains will require because of this, which might get 'interesting'...

 

[najaB]

What does it matter. Still the taxpayer at the end of the day.

There's a big difference between spending money that's in your pocket now and getting less money than you expected to get in the future.

 

[Peter Sarf]

The driving coaches (with less seats) are 2 of the ones witout engines so your maths is slewed the wrong way, its about 30%-40% seats in coaches with no engines.

Oh dear there was me assuming every other coach had an engine under it . Would have made sense to stick an engine under the coaches with the least seats but I suppose the space might already be occupied with things associated with the driving cab !. So on a five car IEP the end coaches are probably the lightest ?.

 

[ainsworth74]

Oh dear there was me assuming every other coach had an engine under it . Would have made sense to stick an engine under the coaches with the least seats but I suppose the space might already be occupied with things associated with the driving cab !. So on a five car IEP the end coaches are probably the lightest ?.

Actually I think they're occupied with the transformer as the pantograph are in the driving vehicles. Which also means, I suspect, that they won't be all that much lighter.