MML Electrification: progress updates

[59CosG95]

I think new feeders on the northern ECML as part of the upgrade there are getting solid state electronic converters that use all the phases symmetrically. So perhaps Braybrooke will be the same?

No, I don't believe that'll change the game much on the MML. The ECML is only getting SFCs because there aren't any 400kV National Grid supply lines nearby; one of those goes right over the railway at Braybrooke.

To put 400kV supply points in at Marshall Meadows & Hambleton Jn would have required new 400kV transmission lines to be built.

 

[InOban]

I would have thought that even using a 400kv supply that the grid would prefer using a SFC powered by all three phases rather than a traditional feeder using only one.

 

[gingertom]

I would have thought that even using a 400kv supply that the grid would prefer using a SFC powered by all three phases rather than a traditional feeder using only one.

Braybrook's capacity from being 400kV fed will come into its own once the wires extend north from Market Harborough.

 

[InOban]

I wasn't doubting the use of the 400kv supply. I was suggesting that all future feeds would use SFC technology so that power is drawn from all three phases. Much easier for the Grid.

 

[gingertom]

I wasn't doubting the use of the 400kv supply. I was suggesting that all future feeds would use SFC technology so that power is drawn from all three phases. Much easier for the Grid.

I agree, SFCs help minimise the imbalance between phases, which is good for the grid. However the power capability of an SFC installation is much less than that of the traditional 400kv feeder station and Braybrook appears to be strategically placed to serve north, south and the Kettering branch. I suspect an SFC would satisfy the initial requirements but when wires progress beyond MH an upgrade would be required. Might it start off as SFC then upgrade, and relocate the equipment? All down to costs.

 

[Bald Rick]

Might it start off as SFC then upgrade, and relocate the equipment?

If it needs to be a grid connection for the full electrification, then a grid connection is what it will be.

 

[edwin_m]

If a grid connection is acceptable on a 400kV supply and that's what's present at the site then there's no reason to install a SFC first and upgrade later.

 

[WAO]

The SFC 's role is to produce power from lower capacity and voltage supplies, such as from the distribution and supply networks, freeing the railway in part from needing supply from the transmission grid. This is explained in the ECML upgrade posts.

The MMLEP is cleverly designed with relatively few high capacity ATFS sites, only Braybrooke needing a new compound. The maximum power it would draw from a 400kV line would be less than 5% of line capacity, not a great imbalance.

WAO

 

[Nottingham59]

The 400kV line at Braybrooke carries two separate circuits. Would a feeder like this typically take a tap from both circuits, so that it can switch between them for redundancy? Or would one circuit be usual, given that current could always be taken from the next feeder along the line?

 

[InOban]

My thought was that we are currently in the first generation of these SFCs and that with time they will be capable of providing more and more power from higher and higher grid voltages. I had understood that the long lead times for 400kv ATFS sites was down to the grid operators needing to accommodate the phase imbalance.

 

[Elecman]

Presumably Grid will look at the phases used at the WCML feeder station near Rugby and choose the opposite phases for Braybrooke

 

[HSTEd]

Ultimately it is likely SFCs will eventually become standard equipment.

We are not quite there yet, but the operational advantages for both the railway and the grid are substantial.

 

[Bald Rick]

We are not quite there yet, but the operational advantages for both the railway and the grid are substantial.

Not to say the cost advantages!

 

[59CosG95]

Home - Whitfield Consulting Services

whitfieldconstructionservices.co.uk

The civils design for Napsbury & East Hyde substations has been awarded, coincidentally to the same engineering designers who were awarded the civils design for Braybrooke.

 

[richieb1971]

Are the bi modes a new class or a pre existing one?

 

[gingertom]

Are the bi modes a new class or a pre existing one?

this thread https://www.railforums.co.uk/thread...way-construction-introduction-updates.195052/ has the info you seek. Hitachi AT300 based with 24m bodyshells (so a pair can fit St Pancras' platforms) and traction package tailored to the MML.

 

[Mag_seven]

Can we try and keep this thread confined to the discussion of updates to the electrification scheme.

I've created a new thread about the post electrification TT that can be found here:

(1) MML Post Electrification Timetable | RailUK Forums (railforums.co.uk)

and as linked to by @gingertom a thread about the new Hitachi Rolling stock can be found here:

https://www.railforums.co.uk/thread...way-construction-introduction-updates.195052/

Thanks Everyone

 

[Edvid]

This HST cab video of a St Pancras-Nottingham journey provides a (somewhat shaky) view of the UKMS125 OLE between Bedford and Kettering, plus the UKMS100 equivalent over the Corby lines before they diverge.

It also reveals the significant OLE alterations taking place in preparation for the new station at Brent Cross West. (Is it still Mk 3b there? Or another OLEMI designation?)

 

[GRALISTAIR]

Approximately when does the (proposed) site of the Braybrooke grid feeder appear in the film?

 

[Edvid]

It doesn't. A few portions of the journey (including the stretch between Desborough and approx. a mile west of the Braybrooke site) were trimmed off.

 

[59CosG95]

It also reveals the significant OLE alterations taking place in preparation for the new station at Brent Cross West. (Is it still Mk 3b there? Or another OLEMI designation?)

AFAIK it's still Mk3b there (I think spanwires and insulators have been the sole components for renewal so far). I'd expect the OLE to either be UKMS or, at the very least, Mk3d (same span and tension lengths as Mk3b but with Bz II (Bronze Two) catenary, flexible current-carrying droppers and more droppers per span).

 

[Edvid]

I see. Between those two, I'd plump towards the Brent Cross MIRs being a Mk3 variant, given that two different types of MIR* share portals where the original and new slow line wire runs overlap at Bedford.

[* One looks like the new kit north of Bedford (UKMS), the other like said assemblies in Brent Cross]

 

[Supercoss]

New overhead line damaged in overnight possession by road rail vehicle, so up slow now blocked from Wellingborough ,(Sharnbrook jcn) to Bedford North until repaired

 

[WymoWanderer]

New overhead line damaged in overnight possession by road rail vehicle, so up slow now blocked from Wellingborough ,(Sharnbrook jcn) to Bedford North until repaired

Perhaps that would explain why there was orange earthing clamps on the slow line at Wymington this morning.

 

[Edvid]

Dynamic OHLE testing of the Bedford-Corby stretch finally concluded last week.

 

[43066]

Dynamic OHLE testing of the Bedford-Corby stretch finally concluded last week.

A job very well done!

 

[GRALISTAIR]

A job very well done!

Indeed so.

 

[flitwickbeds]

Back on a train for the first time this week after my employer allowed driving into London and picked up the bill for it since before Christmas.

The new blue trains are all parked up in Cricklewood sidings. Do we know how many there are in total? Also, will they only start on May 16th as one "big bang" or will we see them serving Corby before the timetable change?

 

[swt_passenger]

Back on a train for the first time this week after my employer allowed driving into London and picked up the bill for it since before Christmas.

The new blue trains are all parked up in Cricklewood sidings. Do we know how many there are in total? Also, will they only start on May 16th as one "big bang" or will we see them serving Corby before the timetable change?

21 Units. There’s a whole thread about them in the rolling stock area:

EMR Class 360's

With the first 360 leaving Greater Anglia on path https://www.realtimetrains.co.uk/train/R52088/2020-06-07/detailed I thought it were best to create a thread on them to track the progress.

www.railforums.co.uk

 

[Brissle Girl]

An interesting article in Modern Railways on how introduction of a pile cap enabled SPL to use standard foundations on 93% of the MML scheme, instead of around 40% without, resulting in a halving of the time, and presumably enabling cost savings too on what typically amounts to a third of the total electrification cost.

Elsewhere it notes how SPL is working with NR to develop continuation of electrification further north than Market Harborough, with plans divided into 8 route sections. With the connection at Braybrooke in place, presumably there is some element of progress north that would be limited to stringing the wires up, so maybe there is a low cost win that takes the scheme closer to Leicester at a relatively low cost per km track mile if there was the desire to keep things moving.