GWML Electification

[robertcwp]

The wire runs may be up, but there is still a lot of work to be done before they would be fit for operations. Judging by my own station (West Drayton), there are droppers missing, catenary and contact wires out of longitudinal register with each other (and that within a few spans of a mid-point anchor), contact wire held up by temporary straps, and so on. On top of that, I have heard it said that the whole of the Paddington approaches will need to be rewired to cope with the higher fault currents with the new power supply arrangements.

 

It's an interesting comparison with the Southern Railway's expansion of the DC network that the conductor rail out of Waterloo didn't need to be upgraded significantly until the current generation of rolling stock arrived.

 

Jim

Really? What about the major upgrading of the SR system when they switched from Durnsford Road power station to the National Grid supply. Also revamped or replaced many of the substations. The voltage went up a bit in the 1980s too after the 4 Subs had been withdrawn.

[Arun Sharma]

Robertcwp - I believe the point Jim was making was that the actual physical contact systems i.e., conductor rail versus contact wires lasted for 80odd years on the SR [and its successors and forebears] before needing replacement unlike his statement that the equivalent systems coming out of Paddington would require replacement after ?15-20 years.

Edited January 21, 2017 by ted675

[jim.snowdon]

Robertcwp - I believe the point Jim was making was that the actual physical contact systems i.e., conductor rail versus contact wires lasted for 80odd years on the SR [and its successors and forebears] before needing replacement unlike his statement that the equivalent systems coming out of Paddington would require replacement after ?15-20 years.

Correct. And even though we have had 150 lb/yd conductor rail for over 50 years, there is still lots of the older 106 lb/yd rail around on the main lines.

 

Substations have got upgraded anyway as the original equipment wore out and/or technology improved; circuit breakers get replaced, and rotary converters gave way to mercury arc rectifiers, then solid state rectifiers. DC electrification on the Southern has been around for over a century now, and the LSWR was practically the last to adopt the third rail system. It's longer than any of the electrical distribution equipment can be expected to last, apart from the conductor rail itself, and to be fair, there isn't much of the original 100 lb/yd rail left anywhere.

 

Jim

 

Jim

[Edwin_m]

Equally the OLE on the southern WCML was basically in original condition from the 1960s up until the modernisation in the early 2000s, and much of the 1970s equipment further north is largely still as built.  It is the newer where economies were made, particularly in using headspans instead of portals, where premature replacement is proving necessary. 

 

The third rail system is much simpler at the trackside than OLE, but does have much more equipment "behind the scenes", with a substation every couple of miles interlinked by a 33kV (usually) trackside cable.  Upgrades and replacements of these less visible items are still necessary but less obvious than work on the rails or wires.  OLE feeders are tens of miles apart. 

[jamie92208]

From something that I've seen elsewhere the problem with the existing OLE from Paddington to airport junction is that it isn't stiff enough to cope with the pantograph loads that the IEP's run with. I believe that there are similar problems between St Pancras and Bedford when they get full electrification of the Midland Main Line.  As far as I know it's not that the OLE is worn out.

 

Jamie

Edited January 21, 2017 by jamie92208

[Zomboid]

The existing OLE and power supply on both the GWML and MML was specified for a different job to that which it will be asked to do. It might be possible that it'll be up to an increased load, but that's by no means certain.

[robertcwp]

From something that I've seen elsewhere the problem with the existing OLE from Paddington to airport junction is that it isn't stiff enough to cope with the pantograph loads that the IEP's run with. I believe that there are similar problems between St Pancras and Bedford when they get full electrification of the Midland Main Line.  As far as I know it's not that the OLE is worn out.

 

Jamie

Is it to do with not being able to cope with two pantographs at over 100 mph?

 

The ECML might have that problem too, especially at the southern end if they are planning 110 mph 387s operation in 12-car formation at full speed. Not sure if it's intended to run 5-car IEPs in multiple on the ECML like it is on GWR.

[Fat Controller]

I suspect the desire to get rid of headspans, whenever feasible to do so, might have something to do with this.

[jamie92208]

Is it to do with not being able to cope with two pantographs at over 100 mph?

 

The ECML might have that problem too, especially at the southern end if they are planning 110 mph 387s operation in 12-car formation at full speed. Not sure if it's intended to run 5-car IEPs in multiple on the ECML like it is on GWR.

 

I've racked my brains and I think that the multiple pantographs at over 100 mph are on problem, then there is the desire to get rid of the headspans to make maintenance easier and I believe that on the MML there is a need for more electrical capacity once the main line trains start running plus possible freight. 

 

Jamie

[Titan]

It is a bit of both. Headspans are a liability and there would be benefit in replacing them anyway. However higher speeds for multiple pantographs require higher tension in the wires. Higher tension in the wires increases the loading on the structures, particularly on curves. With everything built on the limit there is not much scope for just adding extra balance weights without stuff snapping or falling down... 

[Peter Kazmierczak]

Don't HEX units already run with multiple pans out of Padd?

[Titan]

I expect they are restricted to 100mph.

[Peter Kazmierczak]

Where does 125mph running commence?

[Ron Ron Ron]

.....Not sure if it's intended to run 5-car IEPs in multiple on the ECML like it is on GWR.

 

 

Pairs of 5-car trains will also run on the ECML.

 

For example; pairings consisting of one Bi-Mode (Class 800) + one Electric (Class 801), will run as an EMU from KX northbound and after splitting further north, the Bi-Mode can then run on diesel power (off the wires) to its final destination.

[corneliuslundie]

I tried to look at progress between Newport and Cardiff today on the way to and from the Small Cardiff Exhibition today. It looks like a repeat of further east with at most three consecutive masts erected, then a couple of bases in, then nothing, then a base or two, the a gap, then a mast or two, and so on. Lots of masts lying beside the track though even then there are many gaps. And seemingly almost nothing visible west of Newport station for a couple of miles except a couple of adjacent bases near the station may be for a signal, and nothing in Cardiff. One or two bridges raised but others still being done or (from what I could see|) not started.

Jonathan

[The Stationmaster]

Where does 125mph running commence?

 

Just west of Acton station.

 

That was why I'm sure I read somewhere that headspans would be replaced by 'solid' structures between Acton and Airport Junction (some already have of course) and that it would be part of the GWML funded work to upgrade the structures because it isn't needed for Crossrail operation (although in reality all of the new structures in connection with the Crossrail scheme are of the same types as those being used on the GWML scheme including those in areas where there were previously headspans.

 

Some observations from today 

 

Twyford station  - some masts, on open platforms now erected however the timbering over the holes dug for foundations has not been backfilled and any gaps between the cutouts in the covers and the masts themselves have been neatly filled with white mastic.

 

Twyford - Reading - at least one structure still not erected in Sonning Cutting on the Down (south side while some others already have fittings.  I noted a large road-rail crane in the worksite at Land's End along with other road-rail machines.

All masts now seem to be in place from Sonning Sdgs (west end of the cutting) to Kennet Bridge but I'm not sure if all booms are yet fitted although most seem to be.  

Fittings now being added on all lines from the Kennet Bridge running junctions into Reading station but work is not as advanced as it is west of the station.

As previously reported by St Simon the sections through Platforms 13 & 14 are now wired but are just single sections of catenary.

The registration arm attachments and fittings have obviously been added to the underneath of the overbridge for Platform 13 & 14 lines but the only other line where they are installed is that for Platform 7 (but not wired) leaving 8, 9, 10, 11, 12, & 15 to do (2 x sets of fittings for each line.

 

Reading station - Scours Lane - most fittings now in place and the Up Passenger Loop is partly wired at its western end plus the wires now extend over the Reliefs and into the west end of the depot.

3 X Class 387 on the depot outdoors.

 

Didcot - Steventon - Challow

 

Looks as if all masts and most booms are now in place to the A34 bridge with a couple beyond the bridge on the Up side and 4 or 5 beyond the bridge on the west side.

The 'electrification desert' beyond there is little changed although mast bases now look to be present on both sides right through to Steventon station although there might be a few missing on the Up side between the station site and Causeway Crossing.

 

Masts recommence on both sides approximately half way between Causeway Crossing and Locking East and then continue with various stages f fitment (including a short boom I haven't yet seen elsewhere) to just east of wantage Road where there are a couple of gaps.  

Masts and (I think) all booms are now in place on both sides from just west of Wantage Road to just east of Challow station site including various fittings on some

Most of the Up side bases look to be in at Challow station although some might not be immediately to the west and there look to be goes through the station site on the Down side.

 

Then we go back to reasonably complete masts/booms  and some with fittings before coming to this weeks oddity - there is a single section of complete catenary on both lines which ends roughly in the vicinity of Baulking, then we are back to the usual x before arriving at Uffington where there are no masts and I wonder if all the bases are done?

 

West of Uffington and right through to Shrivenham it is the same old mixture of stretches with masts erected then gaps and it looks as if the worksite at Kinghton is being cleared (although work is far from complete.  From there are there are patches of masts and most bases appear to be done as far as Marston West but from there into Swindon on both sides there are only occasional bases in place, even where trial digs were going on a year ago.

 

Same sort of story from Swindon to Wootton Bassett although there area few more stretches of mast and this pattern continues down the Badminton line but with masts something of a rarity.

 

There seem to be no sign of any work on bases between Westerleigh Jcn and almost Patchway but a number of bases going in around Patchway (to yet another design - involving larger diameter tube filled with concrete, a few of these have appeared near Twyford and in Sonning Cutting but these further west look to be to an even larger diameter).

Some masts, and many bases, are to be in place between Patchway Tunnels west end and Ableton Lane Tunnel.

 

Usual pattern from roughly Undy/Magor to East Usk with many bases still to do and the same around Newport station where - again - the very large diameter concrete filled tube is being use and many.

 

One interesting sight for those who come across them is the assembly used to hold the register arm on the H section single line masts - without a doubt I reckon it is the neatest ohle fitting I've ever seen although I do wonder quite how it will manage when high speeds and string winds mix together .  There are some in the immediate Reading area on the Westbury diveunder lines.

[jim.snowdon]

Maybe, but there are 110mph class 350 units running in multiple on the WCML.

 

Plus, where is the practical limit of 100+mph running on the approaches to Paddington?

 

Jim

[Titan]

Maybe, but there are 110mph class 350 units running in multiple on the WCML.

 

Plus, where is the practical limit of 100+mph running on the approaches to Paddington?

 

Jim

 

The 350's were only allowed to to do 110mph when working singly. I do not know if that is still the case.

[Great Western]

London Mildand Class 350 can work upto 12 vehicle formations at 110mph, I believe it's only the original 350/1 and later 350/3 sets though.

Edited January 22, 2017 by Great Western

[Peter Kazmierczak]

Presumably changing headspans to something more substantial between Padd and Airport Jn wouldn't be the easiest of jobs. Would it require possession ofall the running lines?

[Fat Controller]

Presumably changing headspans to something more substantial between Padd and Airport Jn wouldn't be the easiest of jobs. Would it require possession ofall the running lines?

It would for the installation of the cross-girder, though some of the installation of mounting points might be possible under a smaller possession. I would imagine a lot of this work was done under the 'Big Bang' possession over Christmas.

[The Stationmaster]

It would for the installation of the cross-girder, though some of the installation of mounting points might be possible under a smaller possession. I would imagine a lot of this work was done under the 'Big Bang' possession over Christmas.

 

Over several Christmases

Maybe, but there are 110mph class 350 units running in multiple on the WCML.

 

Plus, where is the practical limit of 100+mph running on the approaches to Paddington?

 

Jim

 

At present 100mph is authorised for 'multiple units' (incl HSTs) from 2m04ch just west of Ladbroke Grove and to 2m06ch (Kensal Green - whatever that means nowadays) on the Up Main, the Reliefs are 80/85 mph west of approximately similar mileages.  MP 2 is  roughly opposite the west end of the site of Kensal Green gasworks.  This is considerably better than the 1967 layout which was 60mph east of Ladbroke Grove (1m73ch) on the Mains.

 

The Down Main rises to 125mph at 4m40ch while the Up Main reduces from 125 to 100mph at 4m60ch - Acton Main Line station is a 4m21ch.  In the past it was 85mph inwards on the Mains from the west end of Acton ML platform.

[Peter Kazmierczak]

Looking again at the video above (taken on 8th Jan), there appear to be a few headspans by the HEX depot at OOC and by Acton yard, then almost totally headspans from Ealing Broadway to Airport Jn.

 

So wasn't done over last Christmas..........

Edited January 22, 2017 by Peter Kazmierczak

[Fat Controller]

Looking again at the video above (taken on 8th Jan), there appear to be a few headspans by the HEX depot at OOC and by Acton yard, then almost totally headspans from Ealing Broadway to Airport Jn.

 

So wasn't done over last Christmas..........

I wonder when they might be done then; I looked to see what might be happening around Easter, but no apparent possessions then.

[jonathan452]

Over several Christmases

 

At present 100mph is authorised for 'multiple units' (incl HSTs) from 2m04ch just west of Ladbroke Grove and to 2m06ch (Kensal Green - whatever that means nowadays) on the Up Main, the Reliefs are 80/85 mph west of approximately similar mileages.  MP 2 is  roughly opposite the west end of the site of Kensal Green gasworks.  This is considerably better than the 1967 layout which was 60mph east of Ladbroke Grove (1m73ch) on the Mains.

 

The Down Main rises to 125mph at 4m40ch while the Up Main reduces from 125 to 100mph at 4m60ch - Acton Main Line station is a 4m21ch.  In the past it was 85mph inwards on the Mains from the west end of Acton ML platform.

I thought that originally with the 1967 layout 90mph was permitted on the down fast (main) from Royal Oak?