Almost certainly easier at Maidenhead, but it wouldn't be too hard to join (with a little bit of demolition!) the former stubs to loop the up relief line "around the back" of Slough to give the relief lines three platforms, which naturally would give your central one. I seem to recall hearing back in the early days a mostly-contiguous 5th line to help with freight was planned which would have seen this done at a number of stations, i.e. West Drayton et al.
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Great Western Electrification Progress
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GRALISTAIR
Established Member
Sorry - I didn't mean to be so abrupt.I thought I would help the discussion along by finding out what the current levels are and in my enthusiasm failed to phrase my post properly. -----
High humidity and slightly elevated temperatures can, as Gralistair says, accelerate corrosion rates.
Don't worry - no offence taken. Good Wikipedia page here: https://en.wikipedia.org/wiki/Accelerated_aging
With current fuel sulphur levels and NOx generation it isn't going to be a current air pollution issue.
Much more likely to be poorly specified material for the earthing bonding point combined with surface contamination from historic pollution (20%-25% of particulate matter used to be from diesel sulphur content (sulphonates) coal combustion won't be dissimilar), a bit of interesting mineral content in the brick /mortar (possibly badly spec'd new mortar with different chemistry to the original) and copious quantities of water as the final magic touch.
(Corrosion was viewed as bit of a dark art when I was at uni)
A good bit of head scratching needed.
reddragon
Established Member
Already, batteries in trains are cheaper, more reliable and better than the GUs fitted in class 800s in particular if used on trains once planned to be class 801s.
Only contractual issues & backward looking people would not make the change in a few years time.
Care to share any actual sources of evidence to back up that series of claims?
Linda smith
Member
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I know that the section between Bristol parkway and St Brides (Newport) is due to go live early next month, followed by the required test period. But why wait for the last section to Cardiff Canton depot to be eventually finished and energised before authorising passenger use?
Why not start running from Newport first? As the last time I down that way, it looked like Cardiff was still many months from being energised and tested.
Why not start running from Newport first? As the last time I down that way, it looked like Cardiff was still many months from being energised and tested.
More paperwork... (getting all the drivers to change stuff just for 3-4 months)
The section just west of Newport may not be reinforced enough for raising pantographs at line speed
IET electric running may still be causing issue for to many units (a number are running diesel only)
After a period of lots of frequent changes GWR seem to be trying to do changes less frequently.
GRALISTAIR
Established Member
That does make a lot of sense -
edwin_m
Veteran Member
That may or may not be so, but what would the range be like on a heavy fast train? With Bristol not electrified, a unit on that run may have to get from Wootton Bassett to Weston and back for example including some fairly fast running. Half the Cardiff service runs on to Swansea, slow but hilly, and the occasional one on to Carmarthen and back. I tend to think that's too ambitious for today's battery technology.
Trying to create a sub-fleet that can only run the Cardiff service and short extensions off the wires such as Oxford would be an operational nightmare with inability to swap sets when something goes wrong.
paul1609
Established Member
The battery range of the Class 379 battery trial unit was around 60 miles.
A DC version was deemed inadequate for the Uckfield Line as the range was insufficient. The range was good enough for the Marshlink but the train wouldn't have recharged sufficiently on a Ashford to Brighton circuit and would have needed to do a return trip to Seaford in between.
Fact is battery performance is improving but you can't overcome the basic physics, we are years away from having an Intercity style battery train.
I did a return trip from London to Cardiff yesterday, so here is my update:-All wiring is complete from the current limit of electrification at Bristol Parkway to Seven Tunnel Junction, from here there is only a few support arms and a few wire runs outstanding all the way up to about half a mile east of Cardiff Central Station, this where the wiring stops on all four roads, from here to Cardiff Central Station all the steelwork is up and nearly all the support arms are attached, I cannot comment on anything further west then Cardiff Central Station but you can see there is lots of steelwork up from the station going west.
As it has already been mentioned on this thread, only Platforms 0-4 at Cardiff Central are being wired, but there is some steelwork that covers the Valley Lines as well, including two portals that are on the viaduct going east into Queen Street Station which also go across the main line below, these are at different heights and look quiet odd, so you could say the Valley Lines electrification has started!
Even though I could not see the rest of the outstanding electrification work west of Cardiff, I guess there cannot be that much further to go, I recon it will be power on all the way to Cardiff by the end of the year.
Let's hope it is not the end of the Great Western Electrification story when the above is completed, we will find out when Boris and his mates gets back to Westminster next month or soon after, surely at least the sections which are currently on hold will get approval, Didcot to Oxford and Chippenham/Bristol Parkway to Bristol TM with the remodelling of Bristol East Junction. Chris Grayling said that he was all for the remodelling work at Bristol and then he done a runner.
A lot has been said about the excessive steelwork that has been used for the electrification project, well the Great Western Railway have got a habit of doing things their own way, Broad Gauge, Lower Quadrant Signals, Diesel Hydraulic Locomotives come to mind, is there any others?
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anthony263
Established Member
Be good if boris will agree to finish the project and get the wires to Swansea
Absolutely, as well as Reading-Basingstoke and the Thames Valley Branches to say the least.
I know it not proper to this thread but I was very impressed with the performance of the Class 800, the acceleration on electric is very good and not too shabby on diesel either, but a downside on this line is Wotton Bassett Junction, surly someone will think "Why have the South Wales trains got to slow down to 70mph at this junction"? and do something about it, I know it is a bit tight there but surly they can do something better than a 70mph turnout.
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If, and it's a very big if, the line is energised to St Bride's on 14 Sep as planned, there is still a large backlog of work to complete before it will be fit for commissioning.
Parkway to St Brides might be energised but the change over can be done stationary in Newport station and not on the move. West of Newport does not need strengthening as there is no need for pan up at speed.
It will not increase frequency of change overs; just moving it from Bristol Parkway, the current temporary changeover point, to Newport the next temporary changeover point. These trains are bimodes after all and were designed to change over on possibly every journey.
Does it take that much paperwork to inform drivers of the change? Are they that inflexible to change for only 3-4 months and then change again? Sounds a pathetic excuse to me.
What is stopping installation of OHLE through to the outskirts of Bristol TM via Bath and via Parkway before junction work starts at Temple Meads, after Cardiff is complete, for continuity of the gangs? There must be bridges to raise now in readiness. Once the junction works at Temple Meads are complete it could be wired in only a few weeks if the masts are planted simultaneously with the trackwork in the blockade as at Reading.
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Briefing drivers was just a supposed reason by members here. It’s much more likely to be:-
1) Availability of people to certify the equipment as safe for passenger trains; whose time is limited and very valuable (expensive)
2) installation (or lack thereof) of end-of-OHL trackside equipment - predominantly balises to prevent a pan up IET proceeding into the dead/incomplete section beyond; also relevant signage - all of which requires extensive and expensive design and validation.
Don’t forget this project is already hugely over budget; and unlike previous major schemes NR has undertaken, they have to justify every penny of public money they spend now they’re on the Government’s credit card. Bristol was dropped because there wasn’t the money to do the work. Simple as that.
1) Availability of people to certify the equipment as safe for passenger trains; whose time is limited and very valuable (expensive)
2) installation (or lack thereof) of end-of-OHL trackside equipment - predominantly balises to prevent a pan up IET proceeding into the dead/incomplete section beyond; also relevant signage - all of which requires extensive and expensive design and validation.
Don’t forget this project is already hugely over budget; and unlike previous major schemes NR has undertaken, they have to justify every penny of public money they spend now they’re on the Government’s credit card. Bristol was dropped because there wasn’t the money to do the work. Simple as that.
Envoy
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Can’t see him looking favourably on the people west of Cardiff if they keep voting Labour!
Parkway to St Brides has to be certified whether done now or in 2020. Surely less sulphurous diesel fumes in Severn Tunnel, less polluted atmosphere, less consumption of more expensive diesel and wear on the engines of IETs would be a good move?
What notices? I haven't seen any special notices at Parkway other than neutral section ones and those will be needed also at St Brides and I thought balises were necessary at all neutral sections to drop and raise the pan. What are these additional signs and balises?
St Brides is not the end of OHLE, it is the end of energised OHLE so the pan will not come to any harm when accidentally running onto already installed dead wires.
You are just making excuses for the bureaucrats not to do it.
coppercapped
Established Member
Re the 'sulphurous fumes', you clearly haven't read my earlier post in this thread, only one page back.
Also pantographs are not dropped at neutral sections, only the high voltage circuit breaker opens. (And then closes after the neutral section...)
And to those who think the line will be energised on 14th September JN114 posted here that
This is not the same as stating it will be energised - only that all safety precautions have to be taken from that date and time as if the overhead were live. Judging by the way work was done in the earlier phases, full energisation will follow over the next six to eight weeks.
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coppercapped
Established Member
Deleted.
Mintona
Established Member
I’ve noticed quite a bit of lineside vegetation removal between Bristol and Chippenham lately, most noticeable at Keynsham, Saltford, Bathampton and Thingley. It’s probably wishful thinking that this could be being done ahead of a new announcement, rather than just regular lineside management though.
reddragon
Established Member
Remember of course, class 801s were originally planned for GWR and the missing bits of OLE can still be installed allowing battery rather than the diesel back up originally planned for the class 801.
The class 379 batteries were very old tech when used with less than half of the capacity of batteries of their time and battery tech & capacity is doubling every 18 months at the moment.
It is still intended to phase out diesels by 2040, so it will happen, just a matter of reaching the cost tipping point.
edwin_m
Veteran Member
That is true but requires the government to have the will and find the money, and depends on what battery technology is by that time. I was referring to the current status of both issues. Even then there would still be long extensions such as Hereford for which some units would probably have to keep a diesel capability.
The 2040 announcement was phasing out of diesel-only. So doesn't cover bi-modes.
duffield
Established Member
Also, we don't actually know yet if he can win a vote of confidence. I understand that *if* every Tory and DUP MP voted for him he would have majority of *one*. I very much doubt that any serious decisions will be taken, or if they are can be relied on as binding, before this is resolved, and there's a very high probability of a general election very soon.
Yes I did read your post a page or two back but chose to go with Gralister that sulphurous fumes in a damp humid atmosphere tends to become acidic and causes more corrosion to the overhead bar and connections than humidity alone.
As to balises at neutral sections, it is immaterial what they do. They still have to be installed at the neutral section at St Brides and are not additional to a temporary end of energisation as was implied in the original post about providing them.
Elecman
Established Member
You don’t have Balises at Neutral Section, you have 2 dumb Automatic Power Control (APC) permanent magnets that trip and reset the main HV breaker on the train when passing through the Neutral Section are completely different and are designed to provide specific information to the trains on board computers for things like Tilt ( on the WCML) or Right Side Selective Door Opening information at stations.
Thanks for that. So are balises used at all at a neutal section? Are balises in place at Parkway where the current end of energisation is or is JN114 having a laugh at us?
Elecman
Established Member
Balises are not used at Neutral sections just APC magnets
Balises are not used at all at Neutral Sections - they’re fitted with APC magnets as described above by Elecman
Balises are fitted at the limits of passenger-authorised electrification - so yes there are some currently installed to the West of Bristol Parkway on the Filton, Avonmouth and Tunnel lines which when an IET passes over them on electric mode commands the train to automatically drop the pans and apply the brakes to protect the train and OHLE from damaging one another. Similarly such installations are present on the line towards Gloucester at Westerleigh Junction, West of Newbury station on the B&H, the various Oxford lines around Didcot and so on.
Bristol Parkway was so provided because it was intended to be the limit of passenger authorised electrification for a significant period of time; the extra effort and expense made sense. It’s also anticipated to be the permanent limit of electrification on some of the routes around there well into foreseeable future - they were always going to need to do a fair bit of the overall design work required. Meanwhile they’re only livening up Patchway to St Brides to enable them to test and certify the equipment east of there while they finish off the installation of the OHLE around Cardiff. The phased introduction plan always had Patchway to Cardiff being signed off as one complete section. There’s also no long term requirement to have end of electrification protection at St Brides; so any installation would only ever be temporary. For a project that has already spent all of its budget and a not insignificant sum on top of it; there isn’t the money to spend on design work and installation of expensive equipment that’s only going to be of use for a few months.
Balises are fitted at the limits of passenger-authorised electrification - so yes there are some currently installed to the West of Bristol Parkway on the Filton, Avonmouth and Tunnel lines which when an IET passes over them on electric mode commands the train to automatically drop the pans and apply the brakes to protect the train and OHLE from damaging one another. Similarly such installations are present on the line towards Gloucester at Westerleigh Junction, West of Newbury station on the B&H, the various Oxford lines around Didcot and so on.
Bristol Parkway was so provided because it was intended to be the limit of passenger authorised electrification for a significant period of time; the extra effort and expense made sense. It’s also anticipated to be the permanent limit of electrification on some of the routes around there well into foreseeable future - they were always going to need to do a fair bit of the overall design work required. Meanwhile they’re only livening up Patchway to St Brides to enable them to test and certify the equipment east of there while they finish off the installation of the OHLE around Cardiff. The phased introduction plan always had Patchway to Cardiff being signed off as one complete section. There’s also no long term requirement to have end of electrification protection at St Brides; so any installation would only ever be temporary. For a project that has already spent all of its budget and a not insignificant sum on top of it; there isn’t the money to spend on design work and installation of expensive equipment that’s only going to be of use for a few months.
Brissle Girl
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Why so angry about it? 99 out of 100 passengers will not notice a jot of difference. So best let the engineers and those responsible for ensuring that our railway is safe make the decision as to the most effective implementation plan. As others have subsequently posted, these things are always a lot more complex than us armchair experts might imagine them to be.
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