MML Electrification: progress updates

[edwin_m]

The have been a lot of accidents at Attenborough crossing

Does the presence or absence of ramps on the footbridge make any difference to that?

 

[StewLane]

Does the presence or absence of ramps on the footbridge make any difference to that?

I was assuming this related to the foot crossing to the nature reserve that has a history of fatalities

 

[edwin_m]

I was assuming this related to the foot crossing to the nature reserve that has a history of fatalities

Track the discussion back to #8027 and I believe we are discussing the road level crossing (with footbridge) at the station. The one in the nature reserve looks easier to replace, with ramps if necessary, though it would take a bit of land out of the reserve itself.

 

[WideRanger]

At Attenborough, I wonder whether they might replace the level crossing altogether with a bridge somewhere further up the line, in either direction (while retaining a footbridge only at the station). There seems to be space at the Barton Lane level crossing, there is currently a footpath from there through to Attenborough village - not sure whether it could be turned into a road. Or in the opposite direction, something around the quarry. It would make the access in the centre of the village more roundabout, but maybe better than a level crossing that is closed even more than now, combined with folk south of the line who seem to like exclusivity.

 

[Eskimo]

I have also now seen a peg! This solitary find was in the car park opposite Sileby station, looking up towards the down fast.

The peg was in a sort of ballast well, which might be hard to notice on the photo, but was dead obvious in reality. What does the process of ‘pegging’ the ballast entail?

 

[Archie810]

I have also now seen a peg! This solitary find was in the car park opposite Sileby station, looking up towards the down fast.

The peg was in a sort of ballast well, which might be hard to notice on the photo, but was dead obvious in reality. What does the process of ‘pegging’ the ballast entail?

I think its to mark the planned location of the catenary poles.

 

[Bald Rick]

MML electrification related - here’s a pic from yesterday of some headspan upgrades near St Albans. I do hope that chap at bottom right is OK

 

[Peter Sarf]

MML electrification related - here’s a pic from yesterday of some headspan upgrades near St Albans. I do hope that chap at bottom right is OK

View attachment 175685

That'll be the lookout .

 

[baz962]

MML electrification related - here’s a pic from yesterday of some headspan upgrades near St Albans. I do hope that chap at bottom right is OK

View attachment 175685

I would hope both on the right are ok

 

[swt_passenger]

That'll be the lookout .

I expect he’s keeping that length of old rail from suddenly moving…

 

[Eskimo]

I think its to mark the planned location of the catenary poles.

Ah, what I meant was, how do they go about sticking the pegs in? What sort of plan / survey / digging are they doing for just these pegs?

 

[59CosG95]

Ah, what I meant was, how do they go about sticking the pegs in? What sort of plan / survey / digging are they doing for just these pegs?

Typically, a 1m^3 hole is dug to find out the type(s) of soil (and depths in that 1m hole thereof) in that given location.
The hole plans themselves are based off a non-AFC (Approved for Construction) revision of the design layout plan, with the purpose being to check if the ground is suitable for the OLE structure at the proposed location, or whether/not any tweaks to the design need to be made. Any changes then typically percolate into the AFC design.
The hole is then backfilled, with the wee peg hammered in.

The details of the soil surveys help inform what type of foundation is used; most of the time, it's just normal 610dia. or (occasionally) 762dia. driven piles.
Sometimes, very occasionally, the foundation design changes - I seem to remember that Desborough (on RS1) needed a handful of concrete foundations, where the ground was augered out, a sleeve was driven in, a reinforcement cage lowered into position, and concrete was then poured. Not being on the project myself, I don't know what the cause for the design change was (or whether concrete foundations were specified from the outset), but the general rule of thumb is that piles are the most efficient option (albeit also the noisiest.)

 

[GRALISTAIR]

Typically, a 1m^3 hole is dug to find out the type(s) of soil (and depths in that 1m hole thereof) in that given location.

Wow. 1 cubic metre is a lot!

 

[Nottingham59]

Wow. 1 cubic metre is a lot!

I always assumed they would just take a soil sample with an auger

 

[themiller]

I always assumed they would just take a soil sample with an auger

If you just plunged into the ground with an auger, you’d potentially end up with the same situation as during the GW electrification where signalling and power cables were damaged because their positions were unknown.

 

[78miles]

The ORR "Letter of Authorisation" for the Kettering to Wigston OLE has recently been posted on the ORR Website:

This authorisation is for the placing in service of, • UKMS 125 Overhead Contact Line System between Kettering North Junction (SPC3 72 M 0676 YDS) to Wigston South Junction (SPC3 95 M 0350 YDS).

Interoperability authorisations | Office of Rail and Road

Details of all the new, major, upgraded or renewed infrastructure or rolling stock projects we have authorised into service under the Railways (Interoperability) Regulations 2011.

www.orr.gov.uk

Just need the electric trains to go with it!

 

[Nicholas Lewis]

The ORR "Letter of Authorisation" for the Kettering to Wigston OLE has recently been posted on the ORR Website:

Interoperability authorisations | Office of Rail and Road

Details of all the new, major, upgraded or renewed infrastructure or rolling stock projects we have authorised into service under the Railways (Interoperability) Regulations 2011.

www.orr.gov.uk

Just need the electric trains to go with it!

Of course by the time the 810's are ready to use it NR will probably want it retested

 

[duffield]

Of course by the time the 810's are ready to use it NR will probably want it retested

Some 810's are already (intermittently) out and about though, being tested, so they should be using the newly authorised section fairly regularly between now and when they eventually go into passenger service.

 

[WAO]

Interesting that Wigston is termed a MPATS. Does this mean that this will be the permanent northern boundary for Braybrooke ATFS, or just temporary until wiring to Syston, the putative southern boundary for the Kegworth (AT?)FS?

WAO

 

[D Mylchreest]

Interesting that Wigston is termed a MPATS. Does this mean that this will be the permanent northern boundary for Braybrooke ATFS, or just temporary until wiring to Syston, the putative southern boundary for the Kegworth (AT?)FS?

WAO

Wow! I'd be grateful for an explanation of this post

 

[Edvid]

Here's a very brief update from NR on OLE125 progress:

OLE upgrades south of Bedford are 60% complete and we're on track to complete the work this summer. Thank you for your patience. There will be disruption this weekend, please check before you travel.

Interesting that Wigston is termed a MPATS. Does this mean that this will be the permanent northern boundary for Braybrooke ATFS, or just temporary until wiring to Syston, the putative southern boundary for the Kegworth (AT?)FS?

Probable answer in bold since Wigston MPATS is accompanied by a neutral section.

Wow! I'd be grateful for an explanation of this post

MPATS - Midpoint Autotransformer Site (midway between feeder stations; a boundary between traction supplies)
ATFS - Autotransformer Feeder Station (entry point for traction supplies)

In a classically-fed system they would generally be labelled Midpoint Track Sectioning Cabin (MPTSC) and Feeder Station (FS) respectively.

Also, inclusion of the Napsbury / East Hyde sites within that authorisation letter is of mild curiosity to me since they've been fully operational for almost two years.

 

[GraphitProjekt]

Here's a very brief update from NR on OLE125 progress:



Probable answer in bold since Wigston MPATS is accompanied by a neutral section.


MPATS - Midpoint Autotransformer Site (midway between feeder stations; a boundary between traction supplies)
ATFS - Autotransformer Feeder Station (entry point for traction supplies)

In a classically-fed system they would generally be labelled Midpoint Track Sectioning Cabin (MPTSC) and Feeder Station (FS) respectively.

Also, inclusion of the Napsbury / East Hyde sites within that authorisation letter is of mild curiosity to me since they've been fully operational for almost two years.

Is there a neutral section at Braybrooke? Or in another terms, does it have 1 or 2 grid supplies.

 

[59CosG95]

Is there a neutral section at Braybrooke? Or in another terms, does it have 1 or 2 grid supplies.

Braybrooke does indeed have a neutral section, and has 2 SGTs (Super Grid Transformers) from the 400kV circuit.

 

[swt_passenger]

Is there a neutral section at Braybrooke? Or in another terms, does it have 1 or 2 grid supplies.

It definitely has two complete grid side supply systems, fed off two grid circuits. They were connected separately, about a year apart, it was covered earlier in the thread, the grid circuits on the two sides of the pylons across the site are separate and can be switched independently.

 

[DDB]

If they expect to be done by June it sounds like we have a winner in the race with the introduction of the new trains so hopefully no diesel running under wires for them.

 

[Edvid]

Not quite that soon. Weekend closures for OLE125 works are publicised up to 1 June but there are more closures booked as far as August (per @Supercoss on WNXX).

I do agree that Class 810 passenger workings probably won't need to utilise the M1-adjacent changeover zone (i.e. operate pan-down on the country-side of Mill Hill Broadway) by the time they eventually commence.

 

[GraphitProjekt]

It definitely has two complete grid side supply systems, fed off two grid circuits. They were connected separately, about a year apart, it was covered earlier in the thread, the grid circuits on the two sides of the pylons across the site are separate and can be switched independently.

Braybrooke does indeed have a neutral section, and has 2 SGTs (Super Grid Transformers) from the 400kV circuit.

Thanks!!
This means, however, that Braybrook A feeds about 25 miles of line to Sharnbrook, while Braybrook B only supplies around 13 miles to South Wigston. Does this mean Braybrook B is expected to supply through South Wigston in some N-1 situations (I know that normally Mid Point substations are only bypassed in N-2 times) - or is it likely all down to where the 400kV connections were available. It is a somewhat notable mismatch especially when fewer electric trains will be on the northern side of the feeder station.

 

[Kneedown]

I do agree that Class 810 passenger workings probably won't need to utilise the M1-adjacent changeover zone (i.e. operate pan-down on the country-side of Mill Hill Broadway) by the time they eventually cocommence.

I was chatting to one of our other Instructors last week who is closer to the 810 project than I am currently, and he confirmed that the power changeover boards for Sharnbrook are not going to be installed, so ac operation from Wigston right through to Pancras. The boards already in place between Elstree Tunnel and Mill Hill will be redundant before they even came into use.
A bit of a silver lining to the 810 delays.

 

[londonmidland]

Adjacent to a new housing development just south of Bedford, I’ve noticed a row of new OLE portals being installed.

These are set back further away from the running lines compared to the existing headspans. Is there going to be a loop installed here?

Picture below shows installation of new overhead wire equipment.

 

[John R]

That will be for the new station at Wixams, for which there needs to be some realignment to make room for the relief line platforms.