Class 800 upgrades to address performance and reliability issues

[FGW_DID]

Is that due to some issue with the OLE? That they'll often have a No Electric section on part of the line?

More than likely just related to an Engineering Possession rather than any ‘issue’ with the OLE.

 

[hexagon789]

More than likely just related to an Engineering Possession rather than any ‘issue’ with the OLE.

So they de-energise the OLE to take up a possession, but allow trains to run through the area on diesel?

 

[FGW_DID]

Effectively yes.

 

[hexagon789]

Effectively yes.

Cheers. I can understand with third rail, BT with overheads I thought it wasn't always necessary perhaps.

 

[Mitchell Hurd]

Hello there. For a while now, I've been wondering why at Didcot, IET's heading towards Swindon depart in diesel mode when they run in electric mode heading towards London. This is when the overhead wires are up as well.

Come December, I take it (subject to all being well), that from London to Cardiff it should be electric all the way?

Also, in an 800 or 802, why do they seem powerful when not every coach's engines are on? A 4 or 5-car Voyager with not all engines working would be very slow.

 

[FGW_DID]

Hello there. For a while now, I've been wondering why at Didcot, IET's heading towards Swindon depart in diesel mode when they run in electric mode heading towards London. This is when the overhead wires are up as well.

Come December, I take it (subject to all being well), that from London to Cardiff it should be electric all the way?

Also, in an 800 or 802, why do they seem powerful when not every coach's engines are on? A 4 or 5-car Voyager with not all engines working would be very slow.

Pay attention at the back of the class!

Due to the ongoing saga of the Steventon bridge (which gets discussed on the forum at length quite regularly) all IETs run through there on diesel. They then pan back up for onwards travel towards Swindon.
Class 387 EMUs when travelling ECS to Cocklebury Sidings have a Speed Restriction (60mph?) whilst going under the bridge.

So even when the overheads are live to Cardiff, until the bridge issue is resolved the IETs will be on diesel for a short stretch between Didcot & Swindon.

 

[Railperf]

Hello there. For a while now, I've been wondering why at Didcot, IET's heading towards Swindon depart in diesel mode when they run in electric mode heading towards London. This is when the overhead wires are up as well.

Come December, I take it (subject to all being well), that from London to Cardiff it should be electric all the way?

Also, in an 800 or 802, why do they seem powerful when not every coach's engines are on? A 4 or 5-car Voyager with not all engines working would be very slow.

Remember a 5 car 800/802 has only 3 coaches with engines underneath while the 9 car version only has 5 coaches with engines underneath.
Neither feels more powerful than a Voyager at any time (in diesel mode), though i never have been on a Voyager with less than 4 out of 5 engines running.

 

[Thunderer]

Remember a 5 car 800/802 has only 3 coaches with engines underneath while the 9 car version only has 5 coaches with engines underneath.
Neither feels more powerful than a Voyager at any time (in diesel mode), though i never have been on a Voyager with less than 4 out of 5 engines running.

I had a very poorly 220019 back in the days of Virgin XC between New Street and Bristol Parkway running on 2 out of 4 engines and it was pretty sluggish with a full train. Would have been more fun going the other way to see how it would have coped going up the Lickey...

 

[Railperf]

The power to weight ratio of a 5- car Voyager on only 4 engines, or a 4 car running on only 3 engines is still higher than an 800/802 with all engines running.
And if your 5-car 800/802 loses an engine - then it is really slow despite a slight uprating of the remaIning two engines. But not as slow as an HST on one power car! The 222 Meridians are my 125mph DMU of choice both performance wise and reliability.
Now that is a machine designed to meet fast end to end journey times.

 

[tgrb]

Getting from Paddington to Chippenham has been fun this afternoon, partly due to a signal problems around Didcot and partly due to SWR availability, my original 15:30 to Weston Super Mare was binned off completely so I got on half a train (5-car) to Swansea at 15:36

Now they are down a set due to the tragic incident yesterday and that’s adds additional pressure, but it got me wondering, if the contract is for Hitatchi to supply trains for services as specified, and this got to be regular, could they be forced to build an extra couple of sets so they can fulfil there side of the bargain. Really there should never be an actual shortages of sets? Or short formed.... what do you think?

 

[37114]

I commute regularly from Chippenham and have to say it has been ages since I had a 5 car set, last year it was prevalent but seem to get pretty solid 10 car or 9 car sets these days. I think that the South Wales incident set is back in use, it went to Paddington last night.

 

[II]

And if your 5-car 800/802 loses an engine - then it is really slow despite a slight uprating of the remaIning two engines. But not as slow as an HST on one power car!

I would disagree that the performance differs that much when one engine is lost, certainly when compared with traction that doesn't uprate the output from the other engines. I have experienced from the cab a 2GU 802 and on average performance is very slightly below what you would expect from a 3GU 800. A 2GU 800 will still do a pretty reasonable job at getting up to 90mph when compared to one with all three GU's in order, time losses are seconds rather than minutes, but getting much above 90mph can be a struggle. Down to one GU and you'll only get to around 60mph (as experienced with the 17:18 PAD-OXF yesterday!).

Generally, when comparing 800s and 802s accelerating (on both diesel and electric), the 802s will be doing around 5mph more at any given point about 30-40mph than an 800 would. Not groundbreaking, but useful.

 

[Railperf]

A 2GU (engine) 800 will still do a pretty reasonable job at getting up to 90mph when compared to one with all three GU's in order, time losses are seconds rather than minutes, but getting much above 90mph can be a struggle. Down to one GU and you'll only get to around 60mph (as experienced with the 17:18 PAD-OXF yesterday!).

Exactly ... so frustration for train crew and passengers if you lose a 1/3 GU's or 2/5 0n a 9-car or 2/6 on 2x 5-car.

Considering the TLC these get, it is hard to understand why this is such a regular issue.
I guess the best way to deal with this is shunt the units with diesel only / and or GU's out off the onto the branch services with lower speeds - I.E Worcester, Hereford Gloucester etc.
And if engines are dropping out due to overheating / blocked radiators , the last thing you want is your remaining engines uprating so that they too overheat much earlier. Has a more permanent fix been found for this, or are the radiators being checked/cleaned more regularly?

 

[Railperf]

Down to one GU and you'll only get to around 60mph (as experienced with the 17:18 PAD-OXF yesterday!).

Ouch...did it leave Paddington on all GU's?
Okay RTT says it left 23L and caped at Slough 34 down!!

 

[hexagon789]

And if your 5-car 800/802 loses an engine - then it is really slow despite a slight uprating of the remaIning two engines. But not as slow as an HST on one power car!

What do they uprate to - the full 938bhp?

 

[tomglazed]

On a journey from Paddington to Exeter St. Davids, we had to add an extra stop at Pewsey due to disruption in the Westbury area, I was surprised to see that upon arrival at Pewsey, all reservation screens and indicators turned off and remained that way until we stopped at Taunton (our first scheduled stop). Curious if other people have experienced this and if people can think of a reason why the system should actually function this way?

 

[Randomer]

It was posted in the main thread that the current train management software cannot cope with adding in additional stops (fairly unbelievable oversight but there you go.)

So in all likelihood the driver removed the current planned journey from the information system and reentered it at the next scheduled stop to prevent it getting out of sequence.

Hopefully at some point this will be resolved in a software update to allow manually adding extra stops to services with reservations.

Original thread (now closed) but I can't find the post in question even with search:

https://www.railforums.co.uk/threads/gwr-class-800.100841/

 

[Railperf]

What do they uprate to - the full 938bhp?

Hmmm

It seems a closely guarded secret. I'm led to believe both 802's and 800s now start at 940hp, derating down to 750hp or lower for 800's, while 802's derate less. A percentage of 85% has been mentioned somewhere - if that is true - you can do the maths.

So if a GU is out - i'm not sure the other engines uprate to a full 940hp throughout the full speed range - as it has been said that the engines suffer a lot of torque surge at full power - hence the reason for a very limited burst of the full 940 horses to around 30mph - and then the derate back to around 85%.
My own personal belief is that the 800's with a GU out were uprating to 802 levels . I.E 85% instead of 75%ish. And so if an 802 loses an engine - it wasn't clear that the remaining engines - already at a nominal 85% would likely uprate any further.
But as I say, it is all a closely guarded secret. So there are no definitive figures out there.
Anyone who can point me in the direction of some more definitive data - please PM me.

 

[samuelmorris]

Hmmm

It seems a closely guarded secret. I'm led to believe both 802's and 800s now start at 940hp, derating down to 750hp or lower for 800's, while 802's derate less. A percentage of 85% has been mentioned somewhere - if that is true - you can do the maths.

So if a GU is out - i'm not sure the other engines uprate to a full 940hp throughout the full speed range - as it has been said that the engines suffer a lot of torque surge at full power - hence the reason for a very limited burst of the full 940 horses to around 30mph - and then the derate back to around 85%.
My own personal belief is that the 800's with a GU out were uprating to 802 levels . I.E 85% instead of 75%ish. And so if an 802 loses an engine - it wasn't clear that the remaining engines - already at a nominal 85% would likely uprate any further.
But as I say, it is all a closely guarded secret. So there are no definitive figures out there.
Anyone who can point me in the direction of some more definitive data - please PM me.

750hp would be 80%, 800hp would be 85%, pretty much exactly. I suspect you may be right about 800s not uprating to 940hp in the event of GU failure - there must be a reason why even 802s derate and that must be that the GUs aren't capable of delivering that output continuously without considerably shortening their lifespan.

 

[hexagon789]

Hmmm

It seems a closely guarded secret. I'm led to believe both 802's and 800s now start at 940hp, derating down to 750hp or lower for 800's, while 802's derate less. A percentage of 85% has been mentioned somewhere - if that is true - you can do the maths.

So if a GU is out - i'm not sure the other engines uprate to a full 940hp throughout the full speed range - as it has been said that the engines suffer a lot of torque surge at full power - hence the reason for a very limited burst of the full 940 horses to around 30mph - and then the derate back to around 85%.
My own personal belief is that the 800's with a GU out were uprating to 802 levels . I.E 85% instead of 75%ish. And so if an 802 loses an engine - it wasn't clear that the remaining engines - already at a nominal 85% would likely uprate any further.
But as I say, it is all a closely guarded secret. So there are no definitive figures out there.
Anyone who can point me in the direction of some more definitive data - please PM me.

Lord that's complicated! Why couldn't they just get an engine that can run at full power constantly? Having 940hp available to top speed is surely possible someway, the whole de-rating thing seems utterly farcical.

 

[Clarence Yard]

What Hitachi have done is try and match the engine performance curve to the required overall journey time whilst at the same time minimizing the torque variation to maximize engine life between overhauls/repairs.

So when we talk about "unmuzzling" the 800 sets to provide 940hp, Hitachi will only increase the raw power up to a certain speed level. People talk about 750hp/940hp as if it were a switch - it's much more sophisticated than that - they set the whole speed range up for a variety of hp "settings", taking into account the natural power curve limit and also the projected demand on the engines under certain operational conditions. They effectively create their own power curve to satisfy the journey time requirements and minimize the cost of engine wear.

Obviously, they regard how exactly they achieve this as their own intellectual property.

 

[samuelmorris]

What Hitachi have done is try and match the engine performance curve to the required overall journey time whilst at the same time minimizing the torque variation to maximize engine life between overhauls/repairs.

So when we talk about "unmuzzling" the 800 sets to provide 940hp, Hitachi will only increase the raw power up to a certain speed level. People talk about 750hp/940hp as if it were a switch - it's much more sophisticated than that - they set the whole speed range up for a variety of hp "settings", taking into account the natural power curve limit and also the projected demand on the engines under certain operational conditions. They effectively create their own power curve to satisfy the journey time requirements and minimize the cost of engine wear.

Obviously, they regard how exactly they achieve this as their own intellectual property.

Part and parcel of the IEP procurement, not something I necessarily agree with, but fairly understood now. What's confused matters is hearing that the 802s have their own power management in a similar style.

 

[Railperf]

Part and parcel of the IEP procurement, not something I necessarily agree with, but fairly understood now. What's confused matters is hearing that the 802s have their own power management in a similar style.

it is no different to what the big car manufacturers do - using the same engine and basic chassis but configuring it in different body styles and power outputs for the customer.
Effectively Dft ordered the Class 800. Hitachi developed and built the eventual product to meet DfT spec for energy use and performance etc. And rather than build a train that met the spec exactly, Hitachi built that using components that have been 'muzzled'. So GWR come along and ordered a variant of that - which is the Class 802.

Of course as Clarence hinted earlier - what has been discovered in testing is that the MTU engines can be uprated from their original 750bhp design setting to a maximum 940hp, but with the loads varying on the alternator and therefore indirectly on the engine, trying to maintain a constant 940hp across the speed range causes surges or spikes of torque that can be damaging to the engine and any connected ancillaries - and of course reduces engine life. So hence the Class 802 version have their own unique power setting - which reduces these surges or spikes in torque.

I had a spell tuning turbo diesel cars and am well aware of what happens when you try to tune these too far. The increases in power and torque are astonishing, but potentially very damaging. It takes a lot of time and patience to develop a map that gives you good and reliable power.

 

[father_jack]

Tiptoptaff will get offended but there we go. Same source as always said 10.03 Paddingon to Penzance has engines overheating. It will stay at a stand at Redruth until engines cool.

 

[irish_rail]

Yes this is disturbingly common on the 802s this week I've had a couple of sets where the engines have got a bit warm and decided not to bother until they cooled down a bit. Seems particularly bad on the b and h when not stopping for long periods...

 

[Meerkat]

All a bit of a concern for Grayling’s bi-mode magic bullet policy!

 

[Railperf]

All a bit of a concern for Grayling’s bi-mode magic bullet policy!

Sounds like a recurring overheat issue. HsTs experienced overheating issues back in the day. Various engineering fixes required over the years. Sounds like this will be an interesting one for Hitachi and MTU to fix..

 

[Railperf]

Yes this is disturbingly common on the 802s this week I've had a couple of sets where the engines have got a bit warm and decided not to bother until they cooled down a bit. Seems particularly bad on the b and h when not stopping for long periods...

especially as there is no 'leccy' to fall back on.

 

[Goldfish62]

Yesterday afternoon there were no less than six 5 vice 10 departures from Paddington between 17.00 and 18.00.

General inside view seems to be that last summer's overheating problems that had supposedly been resolved have returned again this year.

 

[Thunderer]

Yesterday afternoon there were no less than six 5 vice 10 departures from Paddington between 17.00 and 18.00.

General inside view seems to be that last summer's overheating problems that had supposedly been resolved have returned again this year.

If more 9 than 5 cars were built a scenario like this would not have such an impact at rush hour out of Paddington, but there we are, Mr Grayling and the DFT know best GWR passengers should brace themselves for a shoddy service for many years to come.