Great Western Electrification Progress

[Unclepete]

Only about a mile west of Airport Junction apparently. It is Crossrail sponsored work on the GW main and relief lines rather than the "Crossrail line" as such.

I read that it simply moves the boundary between live and dead sections to a more straightforward area of the route (i.e. away from all the flyovers and junctions) and is therefore arguable that its not a big enough stage in the overall process to justify the latest spin.

Oh, ok, thanks. Thought I'd missed something major

Couple of pics here from Midgham over the weekend, just to show current level of mast installation. Also, Ufton Nervet bridge is now due to open this Friday 16th.

 

[Envoy]

I very much doubt it.

The WG of course also have 'plans' for a metro 'stop' at/by Newport Road: http://gov.wales/docs/det/publications/160224-potential-metro-map-image-en.gif I very much doubt that will have been planned for either

So, all the work is going on now to wire this route and if they are going to insert a new station, you would think that the west bound relief would be moved out to accommodate an island platform. Then, the catenary is put in place and all is ready for such a new station. But no, they put all the catenary up now and then decide to insert the station causing disruption and a big increase in the costs. Makes you wonder who is running things - if indeed this is what is happening?

A recent report in the Welsh media suggested a business park at this location along with a Park & Ride. To do this, you would surely need a new dual highway running on the south side of the railway between Cardiff & any proposed south of Newport M4? (The present B road could never cope with the traffic that such a development would generate).

http://www.bbc.co.uk/news/uk-wales-south-east-wales-38157370

The new station, provisionally named Cardiff Parkway, would be built south of St Mellons Business Park.
The business park would focus on science and technology and would have a 1,600-space car park and a bus station.
Initially trains would run to Cardiff and Newport, but could serve London and Cardiff Airport in the future./QUOTE]

PS. As if they would stop London express trains between Cardiff & Newport!

 

[HSTEd]

The idea that 3rd rail is simpler or cheaper really seems impervious to reason in this forum.

So a train stuffed full of high voltage cabling, transformers, high voltage pantographs and all that is really going to be less complicated than a train that contains only low voltage equipment and third rail shoes?


Additionally there is little argument that third rail [infrastructure] is cheaper than 25kV once you use realistic estimates for the cost of both [looking at you NR] and don't overspec the third rail to ludicrous levels.

 

[AM9]

Additionally there is little argument that third rail [infrastructure] is cheaper than 25kV once you use realistic estimates for the cost of both [looking at you NR] and don't overspec the third rail to ludicrous levels.

So that is your view on relative cost of provisioning the two alternatives. How do the through-life costs, (say 60+ years service) compare?

 

[HSTEd]

So that is your view on relative cost of provisioning the two alternatives. How do the through-life costs, (say 60+ years service) compare?

Through life costs are not relevant in this case, beyond that third rail and 25kV both easily beat diesel
Because 25kV has now become so expensive that the capital allowance won't allow it to get built.

 

[AM9]

So a train stuffed full of high voltage cabling, transformers, high voltage pantographs and all that is really going to be less complicated than a train that contains only low voltage equipment and third rail shoes?

So high voltage cabling is no more expensive than 750VDC cables of the same power rating. Transformers are getting lighter and smaller (per watt), pantographs are a few hundred Kg. All of the on-board hardware is proven technology and in constant use accross the globe.
LVDC requires almost as much electronics on board, plus considerably more heavy duty kit lineside just to waste unusable power.

 

[HSTEd]

So high voltage cabling is no more expensive than 750VDC cables of the same power rating.

That depends on your conductor material and your insulation rating costs.
However we could have a huge thread on just that discussion by itself

Transformers are getting lighter and smaller (per watt),

They are getting lighter and smaller at the price of increased cost in terms of using far more expensive magnetic materials than simple electrical steel. They are resorting to things like metglas.

All of the on-board hardware is proven technology and in constant use accross the globe.

And must all be maintained by HV qualified technicians who are expensive to train and pay and equip etc etc.

LVDC requires almost as much electronics on board, plus considerably more heavy duty kit lineside just to waste unusable power.

LV electronics are considerably cheaper to procure and maintain than HV electronics as LV electronics are far more widely used and can be maintained with far less extensive training and preparation.

And the heavy duty kit lineside is cheap even if it is big because ~750V rectifiers are now off the shelf industrial items produced in ludicrous numbers.

 

[Taunton]

Transformers are getting lighter and smaller (per watt), pantographs are a few hundred Kg. All of the on-board hardware is proven technology and in constant use accross the globe.
LVDC requires almost as much electronics on board, plus considerably more heavy duty kit lineside just to waste unusable power.

Can it be explained why transformers on trains are getting "lighter and smaller" with technology advances, whereas lineside kit for the same task with DC, are apparently immune from this and remain "heavy duty".

 

[AM9]

Can it be explained why transformers on trains are getting "lighter and smaller" with technology advances, whereas lineside kit for the same task with DC, are apparently immune from this and remain "heavy duty".

The fact that they are carried with a small energy overhead has driven the development of a more compact design where the higher cost of novel materials becomes worthwhile.
--- old post above --- --- new post below ---

LV electronics are considerably cheaper to procure and maintain than HV electronics as LV electronics are far more widely used and can be maintained with far less extensive training and preparation.

Most of the electronics on 25kV rolling stock runs on medium voltage busses so training is more design-specific rather than being unduly affected by line voltage differences.

And the heavy duty kit lineside is cheap even if it is big because ~750V rectifiers are now off the shelf industrial items produced in ludicrous numbers.

Only as long as the price of copper (or other high current capable composites) is kept affordable. It's weight is also much higher than 25kV cable whatever the insulation is when the voltage drops are comparable.
If you mean rectifiers used in the DC traction electronics (or it's protection), similar devices would be used in the LV electronics parts of HV OLE rolling stock. Bear in mind that apart from metro applications and a very few suburban routes (e.g. some of the lines from NYC), the rest of the world's HV OLE railways prop up manufacturing demand for HV traction-specific components. They all seem to think that DC belongs only in slow urban applications so why would the situation be different here. (No need to answer that, - it isn't different.)

 

[HSTEd]

Only as long as the price of copper (or other high current capable composites) is kept affordable. It's weight is also much higher than 25kV cable whatever the insulation is when the voltage drops are comparable.

In this sort of role I imagine aluminium would be dominant in new build stock these days.
The termination issues that plagued aluminium cables previously have largely been eliminated now through superior materials and design.
And aluminium is cheap - smelters are currently losing their shirts.

If you mean rectifiers used in the DC traction electronics (or it's protection), similar devices would be used in the LV electronics parts of HV OLE rolling stock.

With LVDC you can connect modern MOSFET traction drives directly to the line voltage with only a Metal Oxide Varistor or a big (but cheap and simple) TVS chain to protect it from the voltage spikes in the supply.
It is conceptually far simpler and with SiC electronics, it is incredibly compact and surprisingly cheap.
Can't (yet) do that with 25kV systems.

Bear in mind that apart from metro applications and a very few suburban routes (e.g. some of the lines from NYC), the rest of the world's HV OLE railways prop up manufacturing demand for HV traction-specific components.

Problem is HV AC systems are so balkanised that there isn't actually that much standardisation to be had.
Of the top of my head I can think of at least four systems in common use, 25kV, 12.5kV, 20kV and 15kV. And numerous frequency combinations of the above.

They all seem to think that DC belongs only in slow urban applications so why would the situation be different here. (No need to answer that, - it isn't different.)

Because they don't have a railway that is totally unable to deliver affordable 25kV electrification?
Additionally these railways tend to already be heavily electrified so capital constraints are not relevant to them.

 

[itfcfan]

14 isn't closing. I hope the track is back in the morning as well!

What changes are due on platform 13? Is the track layout changing to allow easier access to platform 12 (i.e. separate from the access to platform 11)? Are either platform 13/14 being lengthened? Or is this simply electrification-related changes?

It seems the short platforms on 13/14 are unlikely to be very useful in their current state due to (a) most services that use them being transferred to Crossrail and (b) longer electric trains making them too short for most (all?) services. I expect some of the slow-line services that don't transfer to Crossrail (mainly the Oxford stoppers) will continue to use them, but when that's electrified I expect the train lengths may be a problem?

 

[jyte]

What changes are due on platform 13? Is the track layout changing to allow easier access to platform 12 (i.e. separate from the access to platform 11)? Are either platform 13/14 being lengthened? Or is this simply electrification-related changes?

It seems the short platforms on 13/14 are unlikely to be very useful in their current state due to (a) most services that use them being transferred to Crossrail and (b) longer electric trains making them too short for most (all?) services. I expect some of the slow-line services that don't transfer to Crossrail (mainly the Oxford stoppers) will continue to use them, but when that's electrified I expect the train lengths may be a problem?

It was my understanding that two platforms (13 and 14 I think) were being combined into one longer one to allow for longer train services. Can't remember if/where I read that or if I just made it up.

 

[swt_passenger]

It was my understanding that two platforms (13 and 14 I think) were being combined into one longer one to allow for longer train services. Can't remember if/where I read that or if I just made it up.

It is P12 and P13 that gets combined into one full length platform, suitable for IEP or 12 car EMUs; with P13 believed to be the one dropped from the numbering system. The new alignment runs through the middle of the three disused parcels lifts if you can picture the area.

P12 is presently not full length and has a conflicting entry, being accessed via points part way along P11, roughly under the suburban footbridge.

PS have attached a small drawing of the area in question, however this is more about EMU and IEP capacity than pure electrification...

 

[Jonny]

So a train stuffed full of high voltage cabling, transformers, high voltage pantographs and all that is really going to be less complicated than a train that contains only low voltage equipment and third rail shoes?

Maybe, but then even 3rd rail units come with inverters and AC traction motors. Transformers and HV equipment are "old hat" and used worldwide. It's hardly complicated from an electrical point of view. Also, increasing the voltage lowers the current and thus reduces resistive losses.

Besides, third rail (as implemented on the former Southern Region of BR etc.) is considered to be dangerous due to the proximity of significant voltages at trackbed level. It continues to be used, but mostly through grandfather rights.

 

[AM9]

Because they don't have a railway that is totally unable to deliver affordable 25kV electrification?
Additionally these railways tend to already be heavily electrified so capital constraints are not relevant to them.

The bottom line is that a 3rd rail electric railway, when compared with an OLE line is an outdated system that has:

higher overall costs when assessed over rail infrastructure investment timescales,
is less efficient in energy terms,
is less reliable during inclement weather conditions,
imposes operational limitations on maximum speeds, acceleration, train loads and traffic density
and most importantly, presents an electric shock hazard to staff, casual access by the public and livestock that is unacceptable in the 21st century.​

The safety aspect alone is enough for the authorities at EU and national level to rule out any further new 3rd rail infrastructure, especially given the litiginous nature of corporate responsibility that exists. The next step will be to replace life-expired 3rd rail equipment with OLE whilst replacing/modifying life-expired structures (overbridges/tunnels etc.) to give the necessary clearances for OLE. The design and manufacture of electric rolling stock has been progressing for over 100 years on both OLE and 3rd rail. The introduction of synchronous ac traction motors and the required control and power electronics has been maturing over decades such that the power collection system is not a constraint. This will ease the transition to an all 25kV ac railway over the next few decades, so in the greater scheme of things, there is no justification for committing capital budgets to an obsolete system with all the above disadvantages.

 

[D1009]

Can anyone explain to me in what way discussion of the relative merits of third rail and overhead electrification are relevant to GW electrification?

 

[dviner]

Can anyone explain to me in what way discussion of the relative merits of third rail and overhead electrification are relevant to GW electrification?

It distracts from all the back-and-forth about Bi-Modes being the death knell of electrification.

It harks back to the misunderstandings arising from the use of rigid overhead conductor in the Severn Tunnel.

Some people just like great big lumps of metal alongside the running rails because pickup shoes never fall off, insulator pots never burst into flames, and you can never have too many track paralleling huts.

 

[Dave1987]

And just as I predicted, and was criticised for predicting, the bi-mode has killed the electrification programme.

Indeed since bi-modes were ordered there has been blow after blow to electrification schemes. We now have MPs questioning whether the disruption caused by electrification is worth it when their constituents can get shiny new trains without the need for any electrification works. With bi-modes there will always be a get out clause to just not bother putting the wires up. The only saving grace may be if the oil price starts to go up again and it starts costing serious amounts of cash for these heavy bi-modes to accelerate as fast as the government wanted them to on diesel power. Apart from that after reading Roger Ford and Ian Walmsley columns in December Modern Railways I can't see electrification being a high priority for years to come.

 

[edwin_m]

It distracts from all the back-and-forth about Bi-Modes being the death knell of electrification.

I'm with the bowl of petunias on both subjects.

"Oh no not again. "

Can the mods please create two threads "25kV vs 750V" and "Have bi-modes killed electrification" so the rest of us can just ignore them?

 

[snowball]

Any others who, like me, mainly inhabit this subforum may not have noticed that GW electrification is to be discussed by the Public Accounts Committee today Wenesday:

http://www.railforums.co.uk/showthread.php?t=139069

 

[HowardGWR]

I'm with the bowl of petunias on both subjects.

"Oh no not again. "

Can the mods please create two threads "25kV vs 750V" and "Have bi-modes killed electrification" so the rest of us can just ignore them?

Where is the 'like' button? I just wish we had an LDECRexile and his colleagues, living near Swindon or somewhere on the GWML. Thanks to those who have bothered. It would cost me at least £80 each time to go and take photos. It would be cheaper to donate a digital camera to some of those who do live along the route who post here and to ask them very nicely if they would do us this favour.

 

[CdBrux]

Indeed since bi-modes were ordered there has been blow after blow to electrification schemes.

So now we get to the root cause: if bi-modes hadn't been ordered the whole scheme would have run on time and to budget, or even ahead of time and under budget enabling far more to have been done to cover all the routes bi-modes are intended for!

Wow! Can you also inform us of the next lottery numbers?

 

[FGW_Lad]

I'm sure I saw wires up at Slough station this evening, although it was dark so could be wrong? Am I right in thinking that Heathrow Junc to Maidenhead is due to be finished by May 2017?

 

[swt_passenger]

I'm sure I saw wires up at Slough station this evening, although it was dark so could be wrong? Am I right in thinking that Heathrow Junc to Maidenhead is due to be finished by May 2017?

That's definitely the current plan. It's been publicised for a couple of months that Maidenhead will have peak EMUs from May 17, and it has been discussed a few times already as and when GWR have made PR announcements, and the necessary track access applications have also been quoted and discussed in these forums, either in their thread or the 387 thread in the rolling stock sub-forum.

It has also been stated by NR that Stockley to Maidenhead is to be 'considered live' from some time in early February. That stage brings in procedures for working on an electrified track irrespective of actual status, I think it is part of the progressive build up for all staff. http://www.railforums.co.uk/showthread.php?p=2775713&highlight=maidenhead#post2775713

A similar advanced 'go live' date was declared for the Twyford to Didcot area last summer.

 

[D1009]

Will it become live as soon as the electrification is joined up at Stockley, or will it be separately fed?

 

[swt_passenger]

Will it become live as soon as the electrification is joined up at Stockley, or will it be separately fed?

The grid feed points are at Kensal Green and Didcot. AIUI from earlier discussions Maidenhead (just west of) is the mid point of the route.

My point was to emphasise that the published 'go-live date' is when it is considered live by all staff, not necessarily fully switched on.

 

[FGW_Lad]

That's definitely the current plan. It's been publicised for a couple of months that Maidenhead will have peak EMUs from May 17, and it has been discussed a few times already as and when GWR have made PR announcements, and the necessary track access applications have also been quoted and discussed in these forums, either in their thread or the 387 thread in the rolling stock sub-forum.

It has also been stated by NR that Stockley to Maidenhead is to be 'considered live' from some time in early February. That stage brings in procedures for working on an electrified track irrespective of actual status, I think it is part of the progressive build up for all staff. http://www.railforums.co.uk/showthread.php?p=2775713&highlight=maidenhead#post2775713

A similar advanced 'go live' date was declared for the Twyford to Didcot area last summer.

Thanks for the info. It will be strange to see EMUs through Slough as I have grown up with the noise of the turbos and the ear deafening sounds of HSTs. Any idea when Reading to Maidenhead is due to be complete?

 

[swt_passenger]

Thanks for the info. It will be strange to see EMUs through Slough as I have grown up with the noise of the turbos and the ear deafening sounds of HSTs. Any idea when Reading to Maidenhead is due to be complete?

A few pages back in this thread it was suggested Dec 2017. No reason it wouldn't be easily achievable.

 

[GRALISTAIR]

A few pages back in this thread it was suggested Dec 2017. No reason it wouldn't be easily achievable.

Agreed especially as Oxford, Swansea, TV Branches, Bath have been put on hold -all the focus can go on the core.

 

[reddragon]

Well Stockley Junction west to near West Drayton was switched on last week.

Yesterday I checked the reliefs. From Maidenhead to Stockley they are almost complete. There was a gap on the up relief near Taplow and a few short gaps around Slough. Looks like a February switch on is viable.

I could not see the mains due to low light but before they mirrored the reliefs.

387130-131 are now at Reading, more 387s are being delivered so the May 2017 peak services to Maidenhead seem very likely to happen.