Abellio Greater Anglia Class 755s (Regional Trains)

[Dave1987]

Why not? Through a combination of water and oil heating and glow plugs and similar heating elements I see no reason why the block could not be kept at the optimal temperature.

Cylinder bore experiences temperatures of up to 600 degrees on the ignition of the fuel vapour. Last time I checked even when you pressurise water you can only gets its boiling point up to 120 degrees. And the water jacket is what surrounds the cylinders

 

[Bletchleyite]

Cylinder bore experiences temperatures of up to 600 degrees on the ignition of the fuel vapour. Last time I checked even when you pressurise water you can only gets its boiling point up to 120 degrees. And the water jacket is what surrounds the cylinders

You can use heater plugs to get closer. But surely that cycle is going to occur anyway, both between ignitions of the fuel and on the overrun, when in a car engine no fuel is injected?

 

[Dave1987]

You can use heater plugs to get closer. But surely that cycle is going to occur anyway, both between ignitions of the fuel and on the overrun, when in a car engine no fuel is injected?

Heater plugs are designed for short time to ignite the charge until the cylinder block is at a temperature where the fuel will self combust under pressure. Unless you have fuel vapour being ignited in the cylinders you will never keep the cylinder block at optimum temperatures. As soon as you slow down or stop the combustion process the cylinder block will be cooling down. How and when the engines are used or the thermal cycles managed will be key to the wear. If an engine is going to be fired up you might as well use it for a decent length of time which I expect will be the case for the lines they will be used on.

 

[Bald Rick]

As someone totally ignorant in such matters, can you please explain what is needed, why, and what such specially designed and tensioned OLE looks like?

I ask this because I remember travelling across LGV Nord between Calais and Lille on a Eurostar some years ago, and I was in the front coach and able to see the shadow of the leading power car and its pantographs; at one stage, the driver dropped, then raised, then dropped, then raised a pantograph for some reason, there being reasonable time gaps between each action. By observation, the OLE seemed to be to the same design when the driver undertook these actions as elsewhere on LGV Nord.

Or is it that all LGV OLE is designed so that pantograph raising can take place anywhere on the line?

All LGVs (including HS1 which is designed to French LGV standards) have a level contact wire tensioned at a much higher force than on the GB main line network. So in theory it is better able to withstand pantograph raising at speed.

 

[trebor79]

Looks like this weeks delivery has also been cancelled.

 

[grumpyoldman01]

All LGVs (including HS1 which is designed to French LGV standards) have a level contact wire tensioned at a much higher force than on the GB main line network. So in theory it is better able to withstand pantograph raising at speed.

Thanks for the explanation

 

[Railperf]

So in theory it is better able to withstand pantograph raising at speed.

That is not theory ..that is based on almost 40 years of running TGVs..and many more years of running dual voltage locomotives that need to pan up and down on the move when switching from 25Kv AC to 1.5 Kv DC power supplies.

Checkout this video at around 2 min 45 secs. A double TGV consist raising 4 pantographs simultaneously at speed under 1.5Kv DC catenary

 

[twpsaesneg]

That is not theory ..that is based on almost 40 years of running TGVs..and many more years of running dual voltage locomotives that need to pan up and down on the move when switching from 25Kv AC to 1.5 Kv DC power supplies.

Checkout this video at around 2 min 45 secs. A double TGV consist raising 4 pantographs simultaneously at speed under 1.5Kv DC catenary

I don't think anyone is disputing that the LGV wiring spec is not able to withstand this, only that the UK legacy systems running at substantially lower tensions and with wire grading into and out of bridges and level crossings would perform badly with a risk of damage to both infrastructure and pantograph.

We can and do use pan down coasting on the East and West Coast main lines, with pan back up at speed but the locations are carefully assessed and it is currently only used in limited circumstances.

With respect to the changeovers that could be used with the FLIRTs, I believe it will be more likely that changeover occurs during station duties to start with.

 

[hwl]

Last time I checked even when you pressurise water you can only gets its boiling point up to 120 degrees.

The designers of Sizewell B have a different view, they operate with water (liquid) at 315C and about 60C below boiling point, you just need to pressurise it a bit more!

 

[samuelmorris]

The designers of Sizewell B have a different view, they operate with water (liquid) at 315C and about 50C below boiling point, you just need to pressurise it a bit more!

Indeed, quite a lot more. 150 bar! You'd struggle to fit the equipment for that inside the UK loading gauge...

 

[Railperf]

I don't think anyone is disputing that the LGV wiring spec is not able to withstand this, only that the UK legacy systems running at substantially lower tensions and with wire grading into and out of bridges and level crossings would perform badly with a risk of damage to both infrastructure and pantograph.

We can and do use pan down coasting on the East and West Coast main lines, with pan back up at speed but the locations are carefully assessed and it is currently only used in limited circumstances.

With respect to the changeovers that could be used with the FLIRTs, I believe it will be more likely that changeover occurs during station duties to start with.

Yes..the UK 'knitting' - HS1 excepted - isn't the most robust in the world lol.
As with all these things - the benefits of panning up and down will be assessed along with the risks and costs. If panning up and down allows greater capacity on the network and quicker journeys - then i guess certain sections could be beefed up to allow that if the payback covers those costs.

 

[jopsuk]

you would only really need a few select sections:
1. A short bit of new wiring between Coldham's Lane and Coldham's Road in Cambridge- would not be too challenging given the low speed though care because of tight curve
2. A short section at Norwich between Loddon Road and the mainline
3. A section east of the eastern entrance to Crown Point
4. In Ipswich, between the mainline and the bacon factory curve
5. In Peterborough, from under the mainline

This would allow units to approach, layover and leave stations in urban areas on electric power. It covers most changeovers. The remaining ones are:

1. Ipswich-Peterborough - no benefit to being able to use electric power through Ely
2. Norwich-Cambridge- Pan up during stop at Ely
3. Peterborough/Cambridge-Ipswich- Pan Up during stop at Stowmarket
4. Sudbury-Marks Tey - just run as diesel

 

[twpsaesneg]

you would only really need a few select sections:
1. A short bit of new wiring between Coldham's Lane and Coldham's Road in Cambridge- would not be too challenging given the low speed though care because of tight curve
2. A short section at Norwich between Loddon Road and the mainline
3. A section east of the eastern entrance to Crown Point
4. In Ipswich, between the mainline and the bacon factory curve
5. In Peterborough, from under the mainline

The difficulty is most if not all of these areas are in locations where there is already high driver workload. For a changeover section the driver needs to be in an area where he's not already occupied with other things, like AWS, signals, speed restrictions and the like. There also needs to be suitable length of wiring for the changeover process to start and have enough time to stop the train whilst still under the wires in the event of the diesels not starting up.

For Ipswich and Norwich the balance of operational convenience and cost probably falls to putting units onto hotel power on the wires whilst on layover only and then starting off on diesel.

Peterborough platforms 6 and 7 aren't wired at present, and I suspect the wiring solution for the intersection bridge would be tricky so I can't see any expenditure being authorised there.

Don't get me wrong, I would love to see more wiring and more use of existing infrastructure, but I'm not sure the benefits from trying to get very small amounts of wiring used is worth it - we'd be better pushing for more strategic wiring like Peterborough to Ely and Ipswich to Felixstowe.

 

[Peter Mugridge]

Indeed, quite a lot more. 150 bar! You'd struggle to fit the equipment for that inside the UK loading gauge...

Errr... LMS 6399 "Fury" had a boiler pressure of a maximum 1,800 psi which is 125 bar isn't it?

Yes... I know it was unsuccessful...

 

[trebor79]

Yep. Higher pressures actually mean smaller machines. Hence the very high pressure hydraulics used on the 787, actuators, piping etc are all tiny as a result so there's a weight saving.

 

[AlexNL]

I agree there’s no technical reason. Cash is another matter, as building and maintaining strengthened sections for (potentially) small savings in fuel may be rather overkill. Someone will do the maths no doubt.

If a relatively tiny enhancement to the OHLE helps to improve the air quality in and around the station, the city council might decide to make some funding available.

 

[Bald Rick]

If a relatively tiny enhancement to the OHLE helps to improve the air quality in and around the station, the city council might decide to make some funding available.

But the trains can pan up in the station when stationary at any time. And pan down on the move is fine. So the only air quality / fuel saving would be for the minute or two the train is under the wires entering the station, when the train will be generally not taking power.

For the same amount of cash as building the strengthened OLE, the city council could buy a decent fleet of electric buses which would do far more for air quality.

So all things considered, extremely unlikely.

 

[gazthomas]

Any thing to do with the Stadler trains here, or just catenary and water pressure?

 

[samuelmorris]

Any thing to do with the Stadler trains here, or just catenary and water pressure?

The same as any new fleet thread - it'll go quiet from time to time until more news about their introduction is available. The quiet periods are at the greatest risk of tangential discussions.

 

[Vq4uk]

Would anyone know which one was on the Attleborough to Norwich line to day ?

 

[Rhoobarb]

Would anyone know which one was on the Attleborough to Norwich line to day ?

755407 was your unit - today it's out and about on the GEML

 

[Aureol Colin]

755407 was your unit - today it's out and about on the GEML

Is it allowed to take power from the overhead yet?

 

[Chris125]

Is it allowed to take power from the overhead yet?

Looks like it:

 

[Vq4uk]

755407 was your unit - today it's out and about on the GEML

Thanks very much

 

[Vq4uk]

755407 was your unit - today it's out and about on the GEML

Thanks very much

 

[61653 HTAFC]

Looks like it:

Brilliant... though I bet it woke up every dog in the area!

 

[samuelmorris]

A pleasing lack of transformer noise. Sounds like it'll be pretty quiet when sitting idle.

 

[Bletchleyite]

A pleasing lack of transformer noise. Sounds like it'll be pretty quiet when sitting idle.

I dunno, there's something quite relaxing about the specific note you get from the transformer whine on a Class 319. It's actually quite a nice harmony with the DC traction motors.

 

[dk1]

Is it allowed to take power from the overhead yet?

AFAIK it's still only during the night in a Signal Protection Zone.

 

[samuelmorris]

I dunno, there's something quite relaxing about the specific note you get from the transformer whine on a Class 319. It's actually quite a nice harmony with the DC traction motors.

A 319 yes, an Electrostar or a 385, not so much.