Great Western Main Line electrification - ongoing discussion

[whole diary]

[simonw]

What impact will this decision have on transfer of stock to local and regional services in the Bristol area?

[John R]

I wonder if GWR^▸ (Great Western Railway) has thought about this?

I am sure this has been very much at the top of their agenda for some time now. It would be remarkable if it is not, given how critical this cascade is to the continued running let alone expansion of the regional services.

[IndustryInsider]

What impact will this decision have on transfer of stock to local and regional services in the Bristol area?

Probably not a particularly huge one.  Oxford to Didcot local shuttles could run at their present 30-minute frequency using three units - in fact you could probably get away with two.  Add in one for the Windsor and one for the Henley branches and you might be looking at four or five more units staying that had been envisaged.  Of course, things like the Vivarail D-Train could conceivably be used on both branches to reduce that number even less.

[grahame]

I wonder if GWR^▸ (Great Western Railway) has thought about this?

I am sure this has been very much at the top of their agenda for some time now. It would be remarkable if it is not, given how critical this cascade is to the continued running let alone expansion of the regional services.

The issue has, I believe, been very much on their radar.  Being on the radar is different to being able to wave a magic wand ...

[grahame]

What impact will this decision have on transfer of stock to local and regional services in the Bristol area?

Probably not a particularly huge one.  Oxford to Didcot local shuttles could run at their present 30-minute frequency using three units - in fact you could probably get away with two.  Add in one for the Windsor and one for the Henley branches and you might be looking at four or five more units staying that had been envisaged.  Of course, things like the Vivarail D-Train could conceivably be used on both branches to reduce that number even less.

Relieved to read that ... agrees with my guess in an email to someone.

So what would happen to the four or five class 387s that will no longer be able to take those services over?

D Trains to Windsor would be sort of poetic justice:

http://www.thamesweb.co.uk/windsor/windsorhistory/underground.html

The District line in London started operation on 24th December 1868 running from South Kensington to Westminster. The line was progressively extended from Westminster eastwards towards the City of London and westwards, reaching Hammersmith by 1874, Richmond in 1877 and Ealing Broadway in 1879.
  In 1883 a service was introduced to Windsor from Ealing Broadway using the tracks of the Great Western Railway, but this was withdrawn in 1885.
  So Windsor was once an 'underground' station!

[IndustryInsider]

So what would happen to the four or five class 387s that will no longer be able to take those services over?

Hopefully they'll be used to provide lots of 12-car Swindon to Paddington peak hour services...

[Timmer]

I think the main line can cope with (hopefully temporary) pausing of electrification, Thingley-Bristol-Parkway is not a 125mph stretch of line. The real problem as I see it is by deferring the Oxford electrification the transfer of all those nice 166 Turbos to Bristol for strengthening will be much delayed. This must mean Cardiff-Portsmouth soldiers on for years to come with inadequate 3 car 158s, which might be ok in the middle of the day but not in the crowded peaks. Then of course there is the knock on effect further west with no 158s going to the Barstaple line and presumably no 150s for Devon & Cornwall. I wonder if GWR^▸ (Great Western Railway) has thought about this?

4/5 coach short formed HSTs^▸ (High Speed Train) is what we'll see. Has been mentioned earlier this year though not yet officially announced, just talk in the rail related press. I suspect GWR have known for sometime Network Rail were struggling with this project more so than what we already knew with deadlines slipping backwards.

[Thatcham Crossing]

nothing over 100 between Reading and Newbury

I believe there is a 110 section between just east of Newbury Racecourse and Kintbury, although this is of no use to electric trains that can only run to Newbury.

[onthecushions]

There does seem to be some logic in these delays in that electric traction will be available for the high speed part of the Bristol route although it may be entertaining to see how the diesels cope with the Eastward climb through Box tunnel (1/100). Perhaps the wires should stretch the extra 11 miles beyond Thingley to Bath.
The rest of the line from Bath Westwards is either level or at 1/1320, so should be easy work for a diesel.

Doubtless there is every reason to keep diesels out of the similarly graded Seven tunnel and also the politics of serving the Welsh capital will have a bearing.

The Didcot to Oxford delay seems a pity at first, until one sees the thin entries and exits for Appleford, Culham and Radley but the change needed for those bound for Oxford from Thames valley local stations will be grim, as will be the effects of the smaller "cascade" of Turbos further West.

GWR^▸ (Great Western Railway) will no doubt feel that their bi-modes will fend off Chiltern's competition.

OTC

[stuving]

I don't think the flat-out speed of an 800 matters much in itself, so much as the lousy acceleration up to (say) 160 km/hr. The acceleration at low speeds is limited by adhesion (and sometimes by the drive as well), up to a threshold above which it is power-limited. That threshold is lower when less power is available.

Peering at the back of my (Microsoft-supplied) envelope, it looks roughly like this:                 

	Threshold, km/hr	seconds to 160 km/hr
800, electric	61	113
802, diesel	29	226
800, diesel	37	312
HST▸ (High Speed Train)	60	262

Some of the parameters that were used in that are only estimatesguesses, bit the general trend should be right. And that says ... worse than an HST. And that down-rating really hurts.

Gradients make less difference than you'd expect, at least on this flat track. Once up to speed at below 180km/hr, there is enough power in hand for 1 in 100. (Re)accelerating up any gradient will always be slower, though.

Heating/cooling load also matters, and could be a bigger issue. I don't know how that's done on 80xs, but as Hitachi make HVAC units for trains you'd expect to see that fitted. I don't think they do CO₂ and air-cycle ones, which (as I understand it) are more easily reversed for efficient heating.

[ray951]

This is the National Audit Office (NAO) view on the impact of the electrification delays on the rolling stock cascade:


Does ordering extra AT300's for the Oxford route suggest that the electrification is not just delayed but effectively cancelled?

[JayMac]

I bet FirstGroup are beginning to regret riding on the coat tails of Network Rail with their advertising that promised various improvements by certain dates. Some of those promises may never now be kept and others won't happen for another 2 or more years.

Serves them right for running such a disingenuous ad campaign.

[John R]

This is the National Audit Office (NAO) view on the impact of the electrification delays on the rolling stock cascade:


Does ordering extra AT300's for the Oxford route suggest that the electrification is not just delayed but effectively cancelled?

Interesting the statement about the retention of 11 HST^▸ (High Speed Train)'s.

[ChrisB]

From yesterday's Oxford Area newsletter from NR^» (Network Rail - home page) -

Work continues at Oxford Station to construct new platforms and accommodation building at Oxford Station.  We have  written to our neighbours around  the station to let them know that we will be working 24/7 from Wednesday 9 November to Sunday 11 December.  This work is necessary to allow us to open the new platforms on time on 12 December. We apologise for any inconvenience caused by this work, but can assure our neighbours that we will do everything possible to minimise disruption during this time.

.....
Work on the Down Sidings north of the station


We are currently upgrading and remodeling the ‘Down Sidings’ directly opposite the Oxford University accommodation.
 
 Monday 7th - Friday 11th November
 07:00 to 15:00
 Removal of existing siding 1 and 160 meter renewal of ballast which will include the use of diggers and on track machines.
 
 Saturday 12 November - Monday 14 November
 23:00 – 04:45
 Loading of waste material from siding 1 onto an engineering train for removal from site. Reballast and install sleepers and ballast for new siding 1.
 
 Monday to Friday 14th - 18th November
 07:00 - 15:00
 Excavate 150 meters of spoil for new siding and remove by train, install 150 meters of bottom ballast and reinstate existing sleepers and install new rails.
 
 Monday 21 November - Friday 25 November
 07:00 - 15:00
 Remove 40 meters of spoil and transfer to the yard, install 40 meters of bottom ballast and connect new siding to existing siding. Delivery and installation of new top ballast by engineering train.
 
 Saturday 26th November - Sunday 27th November
 08:00 to 16:00
 Tamping of new siding 1
 A tamping machine or ballast tamper is a machine used to pack (or tamp) the track ballast under railway tracks to make the tracks more durable.
 Install a temporary rail road access point at new siding, to enable us to access the track with the required machinery to undertake work.
 

Monday 28th November - Friday 2nd December
 07:00 - 15:00
 Monday to Wednesday
 Excavate spoil and unload onto engineering train.
 
 Thursday to Friday
 Unload and install 190 meters of ballast and install new sleepers to down siding 2.
 
 Saturday 3rd December - Monday 5th December
 23:00 - 09:00
 Deliver track switching and crossing into down siding 3. Move rail into down siding.
 
 Monday 5th December - Friday 9th December
 07:00 - 15:00
 Install new rails, switches and crossings for the down carriage siding 2, then unload and install new top ballast.
 
 Saturday 10th December - Monday 12th December
 23:00 - 04:45
 Excavate, reballast and install 60 meters of track to connect to new siding 2.
 Remove existing down siding 2 and transfer to engineering train. Lay 60 meters of top stone at south end of new siding 2.
 
 Monday 12th December - Tuesday 13th December
 07:00 - 15:00
 Tamping at new siding.
 Open new siding 2.

[paul7575]

So what would happen to the four or five class 387s that will no longer be able to take those services over?

The full number of 387s is still quite a few less than the originally intended total number of 387s and 365s.    My guess is that the reduced route mileage available to 387s, and the slight reduction in EMU^▸ (Electric Multiple Unit) numbers, will have been broadly allowed for by the recent increase in the number of GW^▸ (Great Western) spec 802s?

Paul