MML Electrification: progress updates

[edwin_m]

If only connected to one circuit and it goes down due to failure or maintenance, then no power can be fed to the railway from this location. Based on previous comments this means the 810s couldn't run on electric, though they could continue on diesel with allegedly little performance impact. So connecting to both seems a sensible precaution - even better if there was access to circuits that didn't share a pylon run!

 

[Nottingham59]

Are they definitely taking power from both circuits on the pylons?

Yes. The site plans clearly show two 400kV transformers, taking power from different sides.


Taken from: https://www.kettering.gov.uk/planx_downloads/5.FloodRiskAssessment.0791.2017.KET.031017.pdf

 

[swt_passenger]

Are they definitely taking power from both circuits on the pylons? Surely one circuit would be sufficient?
For anyone interested, based on what I can work out using OpenInfraMap and Google maps, the circuit currently connected runs from Grendon to Staythorpe, the circuit currently unconnected from Grendon to Cottam (bypassing Staythorpe).

Definitely both sides, if you compare with much earlier photos you can clearly see both sides of that pylon have been extended for the droppers at all 3 levels, and those “triangles of insulators” supporting the grid runs are the key change. We first discussed it back in May 2021 around post #4278, I had posted a link to a very similar planning drawing as @Nottingham59.

Edit: There‘s quite a useful photo in post #5554 that shows an earlier transitional condition, (in July 2022), when they’d extended the western pylon arms and fitted the extra insulators, but the east side was yet to be done. That stage had happened by post #5653, (in Sep 2022).

 

[Nottingham59]

Definitely both sides

Thinking about it, of course you'd want to isolate one side and do the connection work there, then isolate the other and do that at a different time.

 

[Edvid]

If anyone is interested in what all the NG switchgear components are, the designs are bundled with application KET/2020/0256:

SGT1 / SGT2

 

[ohgoditsjames]

Those circuit breakers on the 400kV side are 'Live tank' circuit breakers as opposed to 'dead tank' circuit breakers which are more common (or certainly more common for DNO's).

 

[Nottingham59]

what all the NG switchgear components are,

Thanks for posting those. Glad to see the two transformers are rated at 88MVA. I imagine that would be enough to cover HS2 as well as any electrified freight?

 

[snowball]

Thanks for posting those. Glad to see the two transformers are rated at 88MVA. I imagine that would be enough to cover HS2 as well as any electrified freight?

Surely Braybrooke would have no role in feeding HS2, it's miles away with the WCML in between, and a completely separate project?

 

[Edvid]

Yeah, the HS2 East Midlands branch and I presume the electrified MML between Wigston and further north (if they come to fruition) would be fed from Kegworth.

Given the extent of MMLe distribution/supply works thus far I would be surprised if electrically-hauled freight wasn't accounted for in the planned traction supply. Track capacity may be another matter.

 

[Nottingham59]

Surely Braybrooke would have no role in feeding HS2, it's miles away with the WCML in between, and

Oops. I was getting mixed up with the Kegworth feeder. My mistake

 

[hwl]

Thinking about it, of course you'd want to isolate one side and do the connection work there, then isolate the other and do that at a different time.

Most short isolations for new large grid connections /modifications are done on weekends in summer when the loads are lowest so the the rest of the network can handle the loads and still have minimum specified redundancy incase a problem occurs elsewhere concurrently.
The easier to isolate of the two links has been done first.

 

[Class 170101]

If only connected to one circuit and it goes down due to failure or maintenance, then no power can be fed to the railway from this location. Based on previous comments this means the 810s couldn't run on electric, though they could continue on diesel with allegedly little performance impact. So connecting to both seems a sensible precaution - even better if there was access to circuits that didn't share a pylon run!

Doesn't the picture as altered below also needed to be done like this to enable greater power feeding from all three phases of the power supply rather than just one phase of the sdupply causing the supply imbalance discussed elsewhere.

== Doublepost prevention - post automatically merged: 15 Apr 2023 ==

View attachment 132956

 

[swt_passenger]

Doesn't the picture as altered below also needed to be done like this to enable greater power feeding from all three phases of the power supply rather than just one phase of the sdupply causing the supply imbalance discussed elsewhere.

== Doublepost prevention - post automatically merged: 15 Apr 2023 ==

The detailed drawings show they are only using two phases in this installation. One dropper on each side does not actually continue towards the transformers - post #6182 shows this.

AIUI the use of all 3 phases to prevent imbalance is associated more with SFC based grid supplies fed from DNO 132 kV supplies, as on the recent ECML upgrades.

 

[Elecman]

The detailed drawings show they are only using two phases in this installation. One dropper on each side does not actually continue towards the transformers - post #6182 shows this.

AIUI the use of all 3 phases to prevent imbalance is associated more with SFC based grid supplies fed from DNO 132 kV supplies, as on the recent ECML upgrades.

Correct they are using (For convention) L1and L2 on 1 side of the pylon and L2 and L3 on the other side

 

[snowball]

Press release

Rail passengers advised to plan ahead as Midland Main Line electrification work affects services

Passengers in the East Midlands are being advised to plan ahead on the weekend of 22 and 23 April as electrification work means changes to services between Kettering and Corby.

www.networkrailmediacentre.co.uk

Passengers in the East Midlands are being advised to plan ahead on the weekend of 22 and 23 April as electrification work means changes to services between Kettering and Corby.

There’s also intensive maintenance work between London and Kentish Town at the very southern end of the Midland Main Line, resulting in reduced Thameslink and East Midlands Railway services.

There will be no Thameslink services through central London between St Pancras or Finsbury Park and Blackfriars / London Bridge.

Gary Walsh, Route Director for Network Rail in the East Midlands said: “The electrification of the Midland Main Line is a really important investment for our region. We’re carrying out as much work as possible without affecting services, but some activities need to be carried out when trains aren’t running to keep everyone safe. This weekend is also a busy weekend at the London end of our route where our maintenance teams get longer access to make sure everything is working as it should be.

“I want to thank passengers for their patience while we carry out this work. Please do check your journey before you travel and be aware that some trains may be busier than usual.”

 

[Edvid]

Thameslink is diverted to Platform 1 at StP throughout next weekend, so what particular works require the Moorgate lines to be closed through Kentish Town? Any relation to MMLe, or is it track maintenance/renewals?

 

[Flying Phil]

There is still a mast and pile "Gap" through Great Bowden. There is still a 1/4 mile pile and mast "Gap" to the North of the Braybrooke Supply site but there are temporary barriers and lighting rigs going up alongside the main line. There are piles through Desborough, but no masts yet - about 1/2 mile missing.

 

[Mollman]

Thameslink is diverted to Platform 1 at StP throughout next weekend, so what particular works require the Moorgate lines to be closed through Kentish Town? Any relation to MMLe, or is it track maintenance/renewals?

Thameslink website says:

Engineering work is taking place between London St Pancras International and London Blackfriars, closing all lines.

 

[Edvid]

OK, but that's only the general reason (which I already knew) and doesn't really answer my question. Furthermore, if was just STP-BFR that was shut then Thameslink services could reverse in the low-level platforms at StP and there'd be no need to omit Kentish Town calls entirely, AFAIAA.

 

[Bald Rick]

That block is typically the cyclic maintenance block every three months. It usually covers everything on the TL lines from Dock Jn through to Blackfriars Jn inclusive.

 

[Edvid]

Ah, gotcha. I had briefly wondered if that stretch would be deboostered (assuming it hasn't already been), but I suppose that wouldn't be necessary since the Moorgate lines only handle TL 700s in normal operation anyway.

 

[Bald Rick]

There’s certainly a few block joints that need attention, and some new rail laid out ready for installation.

 

[Flying Phil]

Here are two pictures of the Braybrooke Supply site taken on Tuesday.

 

[PJM]

The `Desborough Gap` is shrinking ! A lot has happened while I have been away for the last 4 weeks.
Looking north towards SPC3/39 from Gladstone Street.


South from SPC3/39


North


South from the Co-op car park. Still a small gap by the car park - no piles or masts.


North from Pipewell Road bridge


South


At the Rushton compound catenary run south/east


Plenty of cantilevers waiting to be installed

 

[59CosG95]

The `Desborough Gap` is shrinking ! A lot has happened while I have been away for the last 4 weeks.
Looking north towards SPC3/39 from Gladstone Street.
View attachment 133563

South from SPC3/39
View attachment 133564

North
View attachment 133565

South from the Co-op car park. Still a small gap by the car park - no piles or masts.
View attachment 133566

North from Pipewell Road bridge
View attachment 133567

South
View attachment 133568

At the Rushton compound double catenary run south/east
View attachment 133569

Plenty of cantilevers waiting to be installed
View attachment 133570

Glad to see it coming on so well now! IIRC there's another total block of the MML between Leicester & Kettering via Mkt H'boro' this weekend so it makes sense to get it more of it done over that way.

Re pic no. 7 - looks to me like catenary & contact have been run over the DM only. The UM cantilever there doesn't have its registration arm attached yet.
And in pic no. 8, I wouldn't be surprised if the bits of steelwork there were all the booms for the boomless masts in the now-shrinking Desborough Gap.

 

[Class 170101]

Glad to see it coming on so well now! IIRC there's another total block of the MML between Leicester & Kettering via Mkt H'boro' this weekend so it makes sense to get it more of it done over that way.

Line through Market Harborough looks open today, reduced service due to St Pancras International being used for GFTR services due to Thameslink core closure.

 

[PJM]

Glad to see it coming on so well now! IIRC there's another total block of the MML between Leicester & Kettering via Mkt H'boro' this weekend so it makes sense to get it more of it done over that way.

Re pic no. 7 - looks to me like catenary & contact have been run over the DM only. The UM cantilever there doesn't have its registration arm attached yet.
And in pic no. 8, I wouldn't be surprised if the bits of steelwork there were all the booms for the boomless masts in the now-shrinking Desborough Gap.

Yes, correct regarding Pic 7, I have amended it. It is double going north from there.

 

[59CosG95]

Line through Market Harborough looks open today, reduced service due to St Pancras International being used for GFTR services due to Thameslink core closure.

Ahhh gotcha. It's still closed tomorrow though.

 

[PJM]

However, this is interesting, there is a long single stretch of catenary on the DM from the Braybrooke supply to Harborough station but a short stretch UM, from Braybrooke supply to Bellfields Lane which is where it stops?

This is Little Bowden footbridge.


== Doublepost prevention - post automatically merged: 22 Apr 2023 ==

Meanwhile, further north, masts through Kibworth as far as the Church Road bridge in the centre of town. After that, piles for quite a long way but not as far as Kilby Bridge.

South of the bridge Newton Lane




North

 

[Nottingham59]

At this rate, they'd better get started on Syston-Trent soon, or there will be another gap after they finish to South Wigston.