Midland Main Line Electrification

[Dr Gerbil-Fritters]

16 hours ago, 96701 said:

Having started this thread on 2nd December 2011, progress seems to be painfully slow.

 

and still no plan to reach Leicester, Derby, Nottingham or Sheffield. 

 

Pathetic.

[great central]

2 hours ago, Dr Gerbil-Fritters said:

 

and still no plan to reach Leicester, Derby, Nottingham or Sheffield. 

 

Pathetic.

 

That's going to be Bi-mode, it's the future don't you know

[class26]

On 26/03/2021 at 09:00, Dr Gerbil-Fritters said:

 

and still no plan to reach Leicester, Derby, Nottingham or Sheffield. 

 

Pathetic.

If you read April`s "Modern Railways" work is now starting on continuation of electrification through to Sheffield. It is divided into 8 sections and work has started to develop the cases for each. 

[Edwin_m]

5 hours ago, class26 said:

If you read April`s "Modern Railways" work is now starting on continuation of electrification through to Sheffield. It is divided into 8 sections and work has started to develop the cases for each. 

To be clear, this "work" will not include anything on the ground, other than probably some surveys.  

[ess1uk]

1 hour ago, Edwin_m said:

To be clear, this "work" will not include anything on the ground, other than probably some surveys.  

Surely that had already been done?

there are bridges north of Leicester that have already been rebuilt to allow the OLE clearance  

[96701]

Maybe there are surveys for cables and drainage being done. So perhaps quite useful "work" on the ground.

[melmerby]

On 26/03/2021 at 11:50, great central said:

 

That's going to be Bi-mode, it's the future don't you know

Hot air & Waffle being the two modes.

[Ncarter2]

Will be interested to see if there are proposals for low bridges to be treated with the new paint recently used on the western route. It allows the gap between the structure and wire to be reduced and also the gap between the top of the train and wire. Saved a multimillion rebuild of a bridge so could be a way forward for other locations which have restricted clearance. 

[cheesysmith]

Just to be clear, is this restricted clearance under the old, worked for over half a century clearance rules, or the new CYA it is someone else who is paying for it clearance rules?

[Zomboid]

7 hours ago, ess1uk said:

Surely that had already been done?

there are bridges north of Leicester that have already been rebuilt to allow the OLE clearance  

It won't include that obviously, but the previously done design work was not sufficiently complete to allow construction to commence so will need to be finished. Also, the train service requirements may have changed, so at the very least it'll have to be validated against whatever has changed.

[Edwin_m]

10 hours ago, ess1uk said:

Surely that had already been done?

there are bridges north of Leicester that have already been rebuilt to allow the OLE clearance  

The clearance needed for electrification is well known and can be provided even if the OLE itself hasn't been designed (give or take issues of standards changes in the last few years, which hopefully by now is water under the, er, bridge).  But as mentioned a lot of design work is needed for the OLE supports themselves, including things like making sure they don't block the view of signals.  

9 hours ago, Ncarter2 said:

Will be interested to see if there are proposals for low bridges to be treated with the new paint recently used on the western route. It allows the gap between the structure and wire to be reduced and also the gap between the top of the train and wire. Saved a multimillion rebuild of a bridge so could be a way forward for other locations which have restricted clearance. 

This treatment comprises surge arrestors to avoid over-voltage in the line due to lighting strikes, and insulating paint.  These combine to allow less clearance between the wire and a metallic bridge above, without unacceptable risk of arcing between the two.  But it's only applicable to metallic bridges because masonry bridges and tunnels are already insulated.  The place it was used with much publicity was the crossing of the Valley Lines over the main line in Cardiff, where raising the Valley lines would have been very difficult and lowering the main line not much easier due to a watercourse underneath.  It remains to be seen whether this technique is preferred for other bridges where the alternatives are less problematic.  

2 hours ago, Zomboid said:

It won't include that obviously, but the previously done design work was not sufficiently complete to allow construction to commence so will need to be finished. Also, the train service requirements may have changed, so at the very least it'll have to be validated against whatever has changed.

This is one of my real bugbears with our stop-start approach to infrastructure "planning" and development.  Some design work is done, then paused, and when it re-starts the first thing to do is to check if it's all still valid, and re-do it if something has changed.  

[Michael Hodgson]

40 minutes ago, Edwin_m said:

The clearance needed for electrification is well known and can be provided even if the OLE itself hasn't been designed (give or take issues of standards changes in the last few years, which hopefully by now is water under the, er, bridge).  But as mentioned a lot of design work is needed for the OLE supports themselves, including things like making sure they don't block the view of signals.  

 

Surely that ceases to be an issue if you provide in-cab signalling on all stock using the route as is supposed to be a long term goal

[Ncarter2]

1 hour ago, Edwin_m said:

This treatment comprises surge arrestors to avoid over-voltage in the line due to lighting strikes, and insulating paint.  These combine to allow less clearance between the wire and a metallic bridge above, without unacceptable risk of arcing between the two.  But it's only applicable to metallic bridges because masonry bridges and tunnels are already insulated.  The place it was used with much publicity was the crossing of the Valley Lines over the main line in Cardiff, where raising the Valley lines would have been very difficult and lowering the main line not much easier due to a watercourse underneath.  It remains to be seen whether this technique is preferred for other bridges where the alternatives are less problematic. 

Given it saved £40m and as stated by NR, it is developing the solution and exploring applications nationwide. Given the purse strings are facing some tough challenges ahead, it’s fair to say this will likely become the preferred option for suitable structures. Internal communications around it seem favourable. I was impressed with the total overall reduction, 90mm. In the video I saw, the pantograph is barely raised. 

[Hobby]

I know there are several places they can't do it (that entrance to Cardiff would be one) but is there any reason they couldn't have a "dead section" under low bridges?

[caradoc]

1 minute ago, Hobby said:

I know there are several places they can't do it (that entrance to Cardiff would be one) but is there any reason they couldn't have a "dead section" under low bridges?

 

There are a couple of reasons; Preferably not at or near where trains are likely to stop for any reason, also if applicable the OLE still has to be sufficiently clear to allow non-electric traction to pass. This solution was adopted on the Paisley Canal route, where otherwise bridge reconstruction costs would have made the electrification unviable, however special instructions (ie OLE isolation) are required for diesel trains, not a major issue as all regular services on the route are EMUs. It was 'interesting', however, the first time the special instructions had to be applied for an overnight engineering train.....

 

[Zomboid]

There are a few neutral section bridges around. They tend to be on minor routes, such as the Romford to Upminster branch and Paisley Canal as mentioned.

 

Those examples both have the advantage of being long one train in section siding arrangements. On a line with more signalling then there are a lot more constraints on where a neutral section can go, and it'd be more luck than anything else if that happened to align with where a difficult to modify bridge was.

 

As for Cardiff, on the face of it that's a great solution, though how it'll perform when it's not brand new remains to be seen. You'd imagine that it would need a bit more attention to ensuring that the special paint doesn't get a coat of more conducive muck building up. But it'll probably take an awful lot of cleaning before the cost of modifying the bridges is spent on it.

[caradoc]

Pedant alert; The Paisley Canal line, which is double track to the approach to Corkerhill Depot, also has a loop between Mosspark and Crookston stations (albeit in the normal TT trains don't actually pass there !)

 

[Sir TophamHatt]

As a side note, are the new 80x trains powered by the front or rear pantograph?

On Pendolinos, it's the rear as if something happens, it'll only damage 3 coaches of the train but if it's the front one, it could damage roof stuff on a lot more coaches.

 

If a neutral section was to be the few metres on the south side of Leicester, if the train is powered by the rear pantograph then it'll be practically clear of the station and at an appropriate speed to not get stuck.  If the train is powered by the front, there could be a problem.

 

I wonder as the new 810s (or whatever they are) will be bi-mode, whether they will (for the life of the trains on this line) change to diesel just before Leicester when running northbound, perhaps even changing in the station back to electric.  And then the same south, swap to diesel just before Leicester and returning to electric just after the station.  Essentially making Leicester station a diesel only station.

 

BUT if the new wires can allow for just 90mm of clearance, it's probably well enough to get under either end of the station, which would give the new 810s a very short life on that route (until other electric trains are bought as / when electrification gets to Sheffield and Nottingham).

Edited April 4, 2021 by Sir TophamHatt
Typo

[iands]

9mm clearance seems very tight to me, or might that be a typo? 

[Chris116]

2 minutes ago, iands said:

9mm clearance seems very tight to me, or might that be a typo? 

I think it should be 9cm.

[Zomboid]

3 hours ago, Sir TophamHatt said:

a side note, are the new 80x trains powered by the front or rear pantograph?

On Pendolinos, it's the rear as if something happens, it'll only damage 3 coaches of the train but if it's the front one, it could damage roof stuff on a lot more coaches.

 

If a neutral section was to be the few metres on the south side of Leicester, if the train is powered by the rear pantograph then it'll be practically clear of the station and at an appropriate speed to not get stuck.  If the train is powered by the front, there could be a problem

I think they usually run on the front pan, but could easily run on the back one.

 

AIUI The new MML trains will be 5 car with only one pantograph vehicle, so it'll be what it'll be as far as leaving Leicester goes. You couldn't electrify on the basis of the pan being at the back of the train without introducing serious compromises to how you use it. Especially on a route where it seems to be very difficult to keep trains oriented one way round (I guess Nottingham to Derby ECS moves mix everything up).

 

It's also likely (I'm just speculating here) that Leicester and Nottingham might be served by 110mph EMUs to/from London in due course.

[Edwin_m]

1 hour ago, Zomboid said:

AIUI The new MML trains will be 5 car with only one pantograph vehicle, so it'll be what it'll be as far as leaving Leicester goes. You couldn't electrify on the basis of the pan being at the back of the train without introducing serious compromises to how you use it. Especially on a route where it seems to be very difficult to keep trains oriented one way round (I guess Nottingham to Derby ECS moves mix everything up).

 

It's also likely (I'm just speculating here) that Leicester and Nottingham might be served by 110mph EMUs to/from London in due course.

Raised pantographs can't be too close together, otherwise the first one sets up vibrations that prevent the second one making good contact.  This is one reason why the pan on an EMU is near the middle. 

 

The necessary separation is speed-dependent, so the 810s on the MML will have a pan front and rear like the five-car 80x in service with other operators.  When two units are coupled they will be raised on the two extreme end cars, and speed will be limited if they have to raise either of the middle ones.  

 

I'm not sure if the low clearance at Leicester is actually fact or enthusiast myth, but if it's true and the best/only solution is a neutral section then trains departing southwards would coast for a short distance (those arriving from the south will be coasting anyway).  I doubt they would start the diesel except in the extremely rare event of being stranded.  

 

Leicester doesn't benefit from HS2 and still needs fast services to London, Derby and Nottingham, and various capacity issues mean it's unlikely that there would ever be more than four London paths per hour.  So I suspect that something similar to the timetable shortly to be introduced will persist for many years.  This includes the use of 125mph units, as even the slower London-Leicester trains will be non-stop south of Kettering where there are significant stretches cleared for that speed.  

[Zomboid]

2 minutes ago, Edwin_m said:

The necessary separation is speed-dependent, so the 810s on the MML will have a pan front and rear like the five-car 80x in service with other operators.  When two units are coupled they will be raised on the two extreme end cars, and speed will be limited if they have to raise either of the middle ones.  

Each 5 car will have 4 diesel engines (apparently), and I thought that there wasn't space for both a pantograph on top and an engine underneath. At least that's an issue with the 800 & 802s.

[Edwin_m]

15 minutes ago, Zomboid said:

Each 5 car will have 4 diesel engines (apparently), and I thought that there wasn't space for both a pantograph on top and an engine underneath. At least that's an issue with the 800 & 802s.

According to March Modern Railways the formation is:

• Driving Trailer First with diesel and pantograph
• Motor Composite with diesel
• Trailer Standard with transformer
• Motor Standard with diesel
• Driving Trailer Standard with diesel and pantograph

There's no particular conflict between a diesel engine and a pantograph, as one's above and one's below.  None of the Hitachi 800-810 has a transformer and a diesel on the same vehicle, as they both need the same underfloor space.  

[Zomboid]

Fair enough, I knew about the diesel/ transformer thing. I had the impression that there wasn't space between the top of the diesel and the bottom of the pan well for proper passenger accommodation, or at least without compromising the access to the passenger saloon.