Infill electrification - definition

[GRALISTAIR]

I sent a tweet or rather replied to a tweet from Roger Ford asking what did he think the definition of infill was as "infill electrification" is allegedly back on the agenda I am genuinely curious. I always assumed it was when both ends were already electrified and you filled in the middle. But that is clearly wrong otherwise Weaver Junction to somewhere south of Glasgow Central in the 1970s would be and it clearly was not.

I assume BPW to Bristol TM is defined as infill but that is not end to end.
I would argue Kettering to Market Harborough is probably infill but I would call it extension. So I know it is a matter of words but what does everyone think?

(ps to mods - don't think this belongs in speculation threads but please feel free if you do think so)

 

[bluenoxid]

I think it requires context and can be used interchangeably.

Context is that either both ends are electrified (which I would definitely call infill for a short run) or one end is electrified and it allows a service to be converted to electric traction (which I would be less likely to call infill unless I was downplaying cost and up selling benefits)

 

[Ploughman]

Neville Hill - Colton would be infill in my book.
Plus Micklefield - Hambleton.

 

[GRALISTAIR]

I suppose Northallerton to Middlesbrough would also be infill.

 

[deltic08]

I would say anything where services can be converted to all electric that were previously mainly "under the wires" diesel.

So just about everything said already.

Trouble is bimodes have skewed or even screwed this definition and the need for more electrification but diesel, battery or hydrogen is not an acceptable alternative to the performance of pure electric on lines with many stops.

Under this definition Northallerton-Middlesbrough, not a borough as in Scarborough, would not become infill until Stalybridge-York is completed.

 

[swt_passenger]

In the 2009 electrification RUS the term “infill” occurs 50 times. One of the early mentions regarding freight is:

“It is envisaged that infill electrification – linking routes which are already electrified – would enable cost savings to be achieved on some routes for operators with existing electric locos.”

http://www.railwaysarchive.co.uk/documents/NR_ElectrificationRUSFinal2009.pdf

Going through the full document may well explain the 2009 view of what was considered “infill”.

 

[Pete_uk]

Conecting two bits of electrified railway which are a relatively short distance from each other

 

[ainsworth74]

Conecting two bits of electrified railway which are a relatively short distance from each other

Yes I'd broadly agree with that. Infill is connecting two bits of electrified railway to each other which are only a short distance apart. Leeds to York is one example given and probably one of the best.

I would, personally, add one other example and this is where you electrify a short branch line that's connected to an electrified route but only where you can then convert the service to EMU operation. For example Oxenholme to Windermere I would consider an infill scheme as it's a short route and every train could be run by EMUs. Whereas Bishop Aukland to Darlington would not be infill as whilst it's short and connected to an electrified mainline the overwhelming majority of trains would have to remain DMUs as most services continue to Saltburn or Middlesbrough. Effectively where you eliminate so called "diesel islands". Oxted to Uckfield might just sneak in as in infill scheme as well by that logic (though 25 miles is quite a long way!).

 

[Ploughman]

Northallerton - Middlesbrough is not Infill, as it does not link 2 lines already under OHLE, but would be extension.

 

[GRALISTAIR]

Whereas CLC route Liverpool -Manchester would be infill in my book.

 

[Elecman]

Lostck-Bolton, Oxenholme-Windermere.

 

[Macwomble]

Cowlairs to Anniesland would, I think, qualify as "infill".

 

[haddock1000]

I think it is also a function of the number of (major) junctions along the line, as well as there being OHLE on both ends. However the length isn't as important IMO.

For example Birmingham to Leeds isn't infill as there are many lines joining and splitting. However, assuming that the East Kilbride branch was done, the Dumfries line would be infill IMO, as it only has a junction to Ayr (ignoring the freight only branch).

Birmingham-Bristol is probably the edge case, meaning that the boundary between infill and not infill being about 3 (Worcester, Gloucester/Chepstow, Stroud/Swindon)

Anyway, that's my tuppence.

 

[adamedwards]

Aston to Rugeley is I assume a good example. Part of the logic is that as the complex bits at each end are done, plain line electrification is therefore cheap making the project more cost effective and so easier to get approved. Edinburgh to Carstairs became cheap to do once ECML electrification paid for Waverley wiring.

 

[Mag_seven]

Acton Bank must qualify as "infill".

I assume BPW to Bristol TM is defined as infill but that is not end to end.

That I would describe as "unfinished"!

 

[MadMac]

Conecting two bits of electrified railway which are a relatively short distance from each other

Good definition. Cowlairs to Anniesland has already been mentioned, and to Westerton would also come under that heading as would Edinburgh Sub. If wires get to Kilmarnock, the Barassie line would be “infill” as would the Larkfield Curve. Would Shotts, at about 20 miles, be stretching it?

 

[InOban]

The larkfield curve was wired a long time ago, you can see the masts on Google. Shotts electrification has just been completed, services start in May.

 

[Mag_seven]

the Larkfield Curve

From where to where is "the Larkfield Curve" please?

 

[LNW-GW Joint]

Aston to Rugeley is I assume a good example. Part of the logic is that as the complex bits at each end are done, plain line electrification is therefore cheap making the project more cost effective and so easier to get approved. Edinburgh to Carstairs became cheap to do once ECML electrification paid for Waverley wiring.

The recent wiring to Rugeley started at Walsall (but Pleck Jn-Walsall was extensively rewired too, as the 1967 scheme only covered one pair of lines).
I'd say Castlefield-Edge Hill was infill, also Huyton-Springs Branch and Ordsall Lane-Euxton, but not Fylde Jn-Blackpool North, where there were major works at the Blackpool end.
Crewe-Kidsgrove was also a typical infill scheme, about the only one justified by disruption elsewhere (the Crewe-Stafford upgrade) and not by its regular traffic.
It works best when the work at terminals and major junctions is already done, reducing the average cost per single track km of the bit in the middle.
You could argue that TP wiring from Victoria East to Copley Hill Leeds will be infill if they ever get round to doing it, but it might be relatively expensive.
Weaver Jn-Motherwell (or was it Lanark Jn) was also infill with Crewe and Glasgow already done, but it was of course a major scheme in its own right considering its size.
GOBLIN was a double infill scheme (a bit in the middle around South Tottenham was already wired, as well as the two ends).

 

[InOban]

From where to where is "the Larkfield Curve" please?

It links the lines from Glasgow central heading towards Polmadie and Carlisle with those heading to Paisley and Ayr. So it fits across the throat of glc. Google is your friend.

 

[Kite159]

It links the lines from Glasgow central heading towards Polmadie and Carlisle with those heading to Paisley and Ayr. So it fits across the throat of glc. Google is your friend.

I was thinking the Larkfield curve is that curve from Larkfield junction to Muirhouse South Jn which only has access towards Crossmyloof?

 

[randyrippley]

Surely infill is a non-linear connection between two linear routes?
For instance Crewe-Glasgow was an extension, but Carstairs-Edinburgh was infill

 

[GRALISTAIR]

Surely infill is a non-linear connection between two linear routes?
For instance Crewe-Glasgow was an extension, but Carstairs-Edinburgh was infill

That was exactly my understanding too

 

[MarlowDonkey]

What about Didcot to Birmingham (New Street) or Didcot to Coventry? Reading to Basingstoke?

If there was such a thing as a dual voltage 387, would it run all the way from Bournemouth to Manchester?

 

[InOban]

I was thinking the Larkfield curve is that curve from Larkfield junction to Muirhouse South Jn which only has access towards Crossmyloof?

The Larkfield curve does as you say, but from the same junction tracks head West towards Shields Road and the lines to Paisley. Do this route have its own name?

 

[MadMac]

I was thinking the Larkfield curve is that curve from Larkfield junction to Muirhouse South Jn which only has access towards Crossmyloof?

Indeed it is.

 

[MadMac]

Crewe-Kidsgrove was also a typical infill scheme, about the only one justified by disruption elsewhere (the Crewe-Stafford upgrade) and not by its regular traffic.

Weaver Jn-Motherwell (or was it Lanark Jn) was also infill with Crewe and Glasgow already done, but it was of course a major scheme in its own right considering its size.

Reference to Crewe-Kidsgrove jogged my memory to Whifflet-Coatbridge Sunnyside, wired to facilitate diversions during the ill-fated Newton remodelling.

It was Weaver Jn-Motherwell plus what was technically an infill from Newton to Eglinton Street via Rutherglen. Would the Rutherglen-Coatbridge electrification count as an infill? What about Shields-High Street (City Union) if it ever gets done?

 

[MadMac]

The Larkfield curve does as you say, but from the same junction tracks head West towards Shields Road and the lines to Paisley. Do this route have its own name?

West Street Tunnel - I believe they’re the “Down and Up Clydesdale”.

 

[Andyjs247]

Although it would just be restarting an existing scheme that has been paused, Didcot-Oxford would I think be an extension. However Oxford to Bletchley and Bletchley to Bedford would be infill.

 

[InOban]

West Street Tunnel - I believe they’re the “Down and Up Clydesdale”.

Thanks. I knew someone would keep me right. I seem to remember it was an early use of slab track because of limited clearance.