IEP bi mode Changeover from Electric to Diesel

[D854_Tiger]

Chiris Grayling claimed this week that bi-mode trains could switch from diesel to electric so seamlessly that the passengers wouldn't even notice, provided they were hard of hearing.

 

However, I presume it is fair to claim the IEP can change mode at speed.

 

How will that occur in practice, what are the sequence of events.

 

Take the scenario of a West of England bound IEP, passing non-stop through Newbury (where the wires will run out), presumably, first things first, the driver shuts off electric power to coast, then lowers the pantograph, then starts the diesels then applies power once more.

 

How is power maintained to the braking system, computers and safety systems, would residual air pressure in the braking system be sufficient for the changeover period.

 

What if any automated mechanisms might exist to aid the process and ensure the correct procedure is followed.

 

How might the process differ if the IEP was stopping at Newbury.

 

How might the set up differ at say Newbury, where IEPs are expected not to stop, verses, say, Oxford or Cardiff where the IEPs will always stop before resuming their journeys on diesel power.

 

Finally, the reverse process, presumably diesels off first then pantograph goes up and how serious (or even possible) might it be for the diesels to be providing power and then be joined by 25kv, to smoke things up a bit, again presumably there are safeguards to prevent all the unwanted scenarios.

[DY444]

The diesel engines can be running whilst the unit is on AC power so they can be started in plenty of time.  I believe the intention is that the changeover will be done automatically with the driver only needing to intervene if there is a problem.   For a non-stop changeover from AC-> diesel, I would expect the transition to start some distance before the wires run out so that if the pan doesn't drop the train can be brought to a stand.  Otherwise the first overbridge west of Newbury will claim more pantographs than Saltwood Tunnel. 

[St. Simon]

Hi,

 

I'm the lead designer for the project to provide Automatic Power Change Over for the IEPs on the Western.

 

I can't got go into any create detail on the project, but yes, the change over will happen a fairly long way from the end of the wires, with the Diesel starting prior to lowering of the Pantograph.

 

Simon

[Ken.W]

I've heard that, in normal service, the train will 'know' where it is and do it itself, starting the diesels about 15 mins beforehand to warm them up first.

 

Power to braking and control systems are maintained by battery supply, hence trains are able to coast after loosing power and don't (normally) come grinding to a stop on passing through a neutral section. There's also been recent occasions of 'high speed coasting' (with pan down) on the ECML which I've described in another thread to get through damaged sections of OHL, and some of these have been around 6 or 7 miles long.

 

As far as reservoir air lasting out to maintain the brake system, in a recent incident after a loco problem I managed to coast about 10 miles into Darlington, pan down, so no power for the compressors, and from an initial speed of only about 80. It was quite critical though at Darlington and was a case of making sure to just use a single brake application! It did avoid stopping where I'd have been blocking the line while sorting the problem though (or seeing if I could sort it).

[Reorte]

Presumably similar in the other direction, the diesel won't go off until the train is taking power from the wires, and the automatic systems should raise the pan at the right time?

[The Stationmaster]

The diesel engines can be running whilst the unit is on AC power so they can be started in plenty of time.  I believe the intention is that the changeover will be done automatically with the driver only needing to intervene if there is a problem.   For a non-stop changeover from AC-> diesel, I would expect the transition to start some distance before the wires run out so that if the pan doesn't drop the train can be brought to a stand.  Otherwise the first overbridge west of Newbury will claim more pantographs than Saltwood Tunnel. 

 

It wouldn't be difficult to outdo Saltwood Tunnel's score of 'pantograph interfaces' as they were actually more likely to hit the signal gantry than the tunnel structure (which did indeed happen on one occasion).  Far cleverer was the one on an Up train that hit Sandling footbridge - due to being raised after passing through Saltwood Tunnel 

[HillsideDepot]

This You Tube clip is interesting as it shows an IET change from diesel to electric, albeit at a stand. I time it as 16 seconds stopping on diesel to starting away on electric.

 

 

 

[Edwin_m]

The diesel engines can be running whilst the unit is on AC power so they can be started in plenty of time.  I believe the intention is that the changeover will be done automatically with the driver only needing to intervene if there is a problem.   For a non-stop changeover from AC-> diesel, I would expect the transition to start some distance before the wires run out so that if the pan doesn't drop the train can be brought to a stand.  Otherwise the first overbridge west of Newbury will claim more pantographs than Saltwood Tunnel. 

 

Another consideration might be that if there is some problem with the diesel mode, this needs to be detected far enough before the end of the wires that the train can stop and reverse on electric power.  This was one reason why the two power supplies overlap between Farringdon and City Thameslink. 

[D854_Tiger]

This You Tube clip is interesting as it shows an IET change from diesel to electric, albeit at a stand. I time it as 16 seconds stopping on diesel to starting away on electric.

 

I have to say that is rather impressive.

[jim.snowdon]

Nonetheless, Eurostar services changed from 25kV OLE to 750V third rail day in day out for many years, all at relatively high speed, under manual control without it being a disaster. Changing an IEP from electric to diesel on the move, even under ddriver control, is not exactly a fundamental problem, nor is it necessarily one that really warrants yet more trackside equipment to operate automatic systems. (Yes, I know the technology is available, but is it actually justifiable, or simply being used because it is there?)

 

Jim

[St. Simon]

Nonetheless, Eurostar services changed from 25kV OLE to 750V third rail day in day out for many years, all at relatively high speed, under manual control without it being a disaster. Changing an IEP from electric to diesel on the move, even under ddriver control, is not exactly a fundamental problem, nor is it necessarily one that really warrants yet more trackside equipment to operate automatic systems. (Yes, I know the technology is available, but is it actually justifiable, or simply being used because it is there?)

 

Jim

 

But on Eurostar, the actual change from one power source to another (OLE to third rail rather than between catenary systems) wasn't carried out at Linespeed, where as the change over for the IEPs will be undertaken at Linespeed, 125mph, and for Eurostar, it had in cab signalling that didn't require much driver input so that he could concentrate on the change over, and for the third rail change over, this happened on an isolated stretch of line with no signalling. For the IEPs, they will be operating (for the most part) using line side signalling, so we need the driver concentrating on that.

 

With both APCO and ASDO, we are minimising the distraction risks to the driver and letting him drive the train rather than having to worry about his power supply or door patterns. The driver can get distracted, even the best can, which could lead to signals or the change over being missed, so the system is provided to ensure safety.

 

Simon

[Titan]

I have to say that is rather impressive.

 

The IET was not bad either!

Edited July 29, 2017 by Titan

[Titan]

But on Eurostar, the actual change from one power source to another (OLE to third rail rather than between catenary systems) wasn't carried out at Linespeed, where as the change over for the IEPs will be undertaken at Linespeed, 125mph, and for Eurostar, it had in cab signalling that didn't require much driver input so that he could concentrate on the change over, and for the third rail change over, this happened on an isolated stretch of line with no signalling. For the IEPs, they will be operating (for the most part) using line side signalling, so we need the driver concentrating on that.

 

With both APCO and ASDO, we are minimising the distraction risks to the driver and letting him drive the train rather than having to worry about his power supply or door patterns. The driver can get distracted, even the best can, which could lead to signals or the change over being missed, so the system is provided to ensure safety.

 

Simon

 

But on Eurostar, the actual change from one power source to another (OLE to third rail rather than between catenary systems) wasn't carried out at Linespeed

 

Simon

 

Um, yes it was...

 

[jim.snowdon]

But on Eurostar, the actual change from one power source to another (OLE to third rail rather than between catenary systems) wasn't carried out at Linespeed, where as the change over for the IEPs will be undertaken at Linespeed, 125mph, and for Eurostar, it had in cab signalling that didn't require much driver input so that he could concentrate on the change over, and for the third rail change over, this happened on an isolated stretch of line with no signalling. For the IEPs, they will be operating (for the most part) using line side signalling, so we need the driver concentrating on that.

 

With both APCO and ASDO, we are minimising the distraction risks to the driver and letting him drive the train rather than having to worry about his power supply or door patterns. The driver can get distracted, even the best can, which could lead to signals or the change over being missed, so the system is provided to ensure safety.

 

Simon

Except that what is happening is that engineers based in offices, however technically competent they may be, are making the driver's job more boring, which is more likely to lead to anything unusual being missed. As ever, the question that arises is as to how much the designers actually know about the driver's environment. The concept of engineers being able to drive trains has never been encouraged, although (and I can speak from experience on this), practical knowledge of train driving is very useful when considering what is practicable on both rolling stock and infrastructure. The railway and the trains that run on it are a system, yet railway management and design is still being carried out in silos, with each department neither talking to another nor having much understanding of the other.

 

Jim

 

Jim

[Fat Controller]

Strictly speaking, the changeover shown at Westenhanger is between the Eurotunnel-height and HS1-height catenary. E* no longer need to change from 3rd rail to 25kV, as all the routes they now use in the UK are fitted with overhead supply.

The driver workload on the old route into and from the Tunnel was quite high; apart from the voltage/ collection system change, TVM had to be armed/ disarmed, inter-vehicle fire-doors activated and deactivated, and Concession Radio/NRN initialised, all in a distance of about two miles at 160 kph.

There were occasions when the third-rail shoes didn't lift correctly on the way into the tunnel. Generally, the strategically located concrete blocks would knock them off, but I can think of one instance where this didn't happen. The shoes hit some lineside equipment, and blocked the normal exit from the Eurotunnel terminal into the North tunnel. That kept me busy all shift.

[DY444]

But on Eurostar, the actual change from one power source to another (OLE to third rail rather than between catenary systems) wasn't carried out at Linespeed, where as the change over for the IEPs will be undertaken at Linespeed, 125mph, and for Eurostar, it had in cab signalling that didn't require much driver input so that he could concentrate on the change over, and for the third rail change over, this happened on an isolated stretch of line with no signalling. For the IEPs, they will be operating (for the most part) using line side signalling, so we need the driver concentrating on that.

 

With both APCO and ASDO, we are minimising the distraction risks to the driver and letting him drive the train rather than having to worry about his power supply or door patterns. The driver can get distracted, even the best can, which could lead to signals or the change over being missed, so the system is provided to ensure safety.

 

Simon

 

Every Eurostar journey still has one changeover which occurs at locations where the signalling changes to/from TVM.  Those are on/off the high speed lines outside Paris and Brussels.  The workload there is high especially going onto the classic networks.  You've also got the two changeovers at Lille which are often accompanied by restrictive speeds on TVM due either to other traffic or the speed reduction necessary to go into one of the platform roads.  The Calais changeover is on a steep gradient and checks approaching the ET boundary are not uncommon either if you present early or late.

[St. Simon]

Um, yes it was...

 

 

I was referring to changes between power sources, rather than between caternary systems shown here.

 

Except that what is happening is that engineers based in offices, however technically competent they may be, are making the driver's job more boring, which is more likely to lead to anything unusual being missed. As ever, the question that arises is as to how much the designers actually know about the driver's environment. The concept of engineers being able to drive trains has never been encouraged, although (and I can speak from experience on this), practical knowledge of train driving is very useful when considering what is practicable on both rolling stock and infrastructure. The railway and the trains that run on it are a system, yet railway management and design is still being carried out in silos, with each department neither talking to another nor having much understanding of the other.

 

Jim

 

Jim

 

All of our designers have been out with drivers on various journeys to help understand the problems that they face, I try to talk to Drivers as often as I can to help understand the task of drivers and their environment, we all sit in on Signal Sighting Committees so we get to hear how trains are driven. When I talk to drivers (both current and former), they say they want as little distractions as possible in the cab.

 

Simon

[DY444]

I was referring to changes between power sources, rather than between caternary systems shown here.

 

 

Simon

 

Don't know about Class 374 but on the Class 373s it makes no difference.  The driver still has to do the same set of things for every changeover irrespective of what the change is from and to, and there are 5 of them between St.Pancras and Paris/Brussels.

Edited July 29, 2017 by DY444

[jim.snowdon]

I was referring to changes between power sources, rather than between caternary systems shown here.

 

 

All of our designers have been out with drivers on various journeys to help understand the problems that they face, I try to talk to Drivers as often as I can to help understand the task of drivers and their environment, we all sit in on Signal Sighting Committees so we get to hear how trains are driven. When I talk to drivers (both current and former), they say they want as little distractions as possible in the cab.

 

Simon

Being out with drivers is better than nothing, although it is never going to be quite the same as actually driving. That aside, my experience of signal sighting committees has not always been positive, especially as they have no requirement in terms of accountability for their decisions.

 

Jim

[Zomboid]

Another consideration might be that if there is some problem with the diesel mode, this needs to be detected far enough before the end of the wires that the train can stop and reverse on electric power. This was one reason why the two power supplies overlap between Farringdon and City Thameslink.

Given the level of redundancy (3 power units in a 5 car bring the worst), the likelihood of a failure that makes the train immobile on diesel pretty close to zero.

 

As for automating it, it seems like a lot of effort and complications for what on the face of it ought too be 3 button presses (engine start, pan down, mode select - or vice versa). Of course, making it reliant on a trackside system means that if it goes wrong, blame can be shifted to NR, and schedule 8 money can therefore be shifted to the TOC. So obviously they'll want it to be part of the infrastructure...

 

Cynic mode disengage.

[jim.snowdon]

The changeover selection need be no more than one switch - diesel mode or electric mode. I don't doubt it was that way on the Southern Region's electro-diesels, and quite possibly on the new class 88s.

 

Jim

[D854_Tiger]

Would it be correct to assume that an all electric IEP will be able to work in multiple with a bi-mode IEP and work in multiple with one unit running on diesel and the other on electric..

 

Also two bi-modes in multiple one working on diesel the other on electric.

 

It may sound hypothetical but on the EC it could be the case that you might want to do it somewhere like approaching Newark, if one set is to be detached for Lincoln, running on diesel, with the other set continuing north on electric.

[D854_Tiger]

I wonder if the five car units will be able to work on electric between Bradford Forster Square and Leeds, something an IC225 cannot do because of power supply constraints.

[Christopher125]

Would it be correct to assume that an all electric IEP will be able to work in multiple with a bi-mode IEP and work in multiple with one unit running on diesel and the other on electric..

 

Also two bi-modes in multiple one working on diesel the other on electric.

Can't find it now but pretty sure I came across a video of two bi-modes working in multiple, one in diesel mode and the other in electric.

 

I wonder if the five car units will be able to work on electric between Bradford Forster Square and Leeds, something an IC225 cannot do because of power supply constraints.

They've been doing that for years haven't they? Skipton was an issue but that's been rectified IIRC.

 

GNER Class 91 at Bradford Forster Square 1999 by Dales Rail Photographic, on Flickr

Edited July 30, 2017 by Christopher125

[modfather]

Last time I was on one, it was via the test engineers laptop.

 

There was suggestion that it will be done by gps for now, obviously ETRMS lines can use this instead.

 

The engines preheat and start in advance and from what I remember of the manuals I read through the train treats it as if it is entering a neutral section as the vcb opens, the pan drops and the aux power supply is brought online, supplied by the diesels.

 

...in theory.