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Post by david3383 on Mar 8, 2008 21:40:07 GMT
Now, the NLL is partly 25kV overhead and partly 750V DC third rail and previously all third rail, are there or have there been plans to convert ALL of the NLL to overhead?
If not, is this because of the section between Gunnersbury to Richmond shared with the District line? Would it be problematic to have overhead for NLL and 630V dc third and fourth rail for the District line?
Previously, I've read that the northern approach to Stratford Low Level (i.e. where the NLL passed under the High Level) has insufficient clearance for overhead but this isn't a problem now that the NLL platforms will be used by the forthcoming Canning Town to Stratford International DLR branch and the NLL will terminate on the High Level along with National Express East Anglia, DLR Poplar-Stratford and the Central line.
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Post by Deleted on Mar 9, 2008 10:49:04 GMT
Why would anyone want to spend several million pounds to fix something that is working fine?
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Post by Deleted on Mar 9, 2008 12:14:17 GMT
beacause there is no point,
the NLL was overhead electrified purely beacause of the freight link so AC locomotives could get through
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Post by cetacean on Mar 9, 2008 18:32:48 GMT
The answer's actually yes, almost.
Trains currently use third rail Richmond-Acton Central, Camden Road-Dalston Junction and Hackney Wick-Stratford. The latter is going to disappear when the new NLL platforms at Stratford come into use at the end of the year. The Camden-Dalston section is due to be completely rebuilt for the ELL extension and the NLL service upgrade, and the tracks used by the NLL will almost certainly be overhead only (the ELL will have its own dedicated third rail tracks to get to Highbury). That means come 2011 the western section is the only place where third rail will be used, and due to the District is unlikely to change.
But OTOH dual voltage trains are easy to build - AC is converted to DC internally, so adding DC to an AC train is as easy as adding shoes, and far easier than getting overhead line working simultaneously with third/fourth rail.
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Post by Deleted on Mar 10, 2008 20:45:35 GMT
The first bit of AC electrification was freight sponsored between Camden Rd and Stratford around 1984 to allow electric haulage WCML - GE / LT&S section - saving re-engining trains and to fit with the Anglia electrifciation (freights could run with 86's Ipswich to Manchester etc direct - saving an hour or so - and lots of engine and crew time) - the incline down to KIngs Cross was also done in the aid of freight off Willesden to ECML - there were plans for a major recast called the "U Bahn" giving direct Crewe - Newcastle freight workings)
The 313's were a logical cascade for their dual voltage capability
Stage 2 was the rebuild for EPS workings (Eurostar) which saw in Sept 96 AC from Acton Central to Camden Rd primarily for very short lived EPS stock moves and of course further 313 AC working as they ran better on the wires than the very old and distorted con rail. THis project incidentally ran 6 months late (sounds familiar)
The next follow up was new AC Willesden HL - North Pole (sig VS808 from memory) which allowed the West London line to go electric and get rid of the awful class 117 DMU.s)
From memory 313020 did the honours on the Hampstead route and 313009 on the WLL as first electrics (the latter was 2 days early !)
There are feeding issues on the Richmond line which caused the changeover to be Acton Central not the more logical Gunnersbury - shame the job wasnt finished off properly and the Kew East - Sth Acton not DC'd to give an electric route onto the Hounslow loop !
Incidentally the first few weeks of AC/DC changeovers saw numerous instances of lost pans as a result of crew unfamiliarity ! - despite extensive briefing
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Post by raakone on Mar 24, 2008 18:10:37 GMT
Surely they could have had a "pantograph down" warning sign, could they?
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Post by Chris M on Mar 24, 2008 21:22:19 GMT
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Post by Deleted on Mar 25, 2008 20:07:02 GMT
Of course there were pan down signs - plus cab stickers , plus briefings , plus notices in messrooms etc etc.
The membershiip of the pan club (embarrasment quota) eventually cured it - plus some old style "management" ......
Not just 313's either - EWS / EPS lost a few long the way .....!
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Post by 21146 on Mar 25, 2008 22:41:59 GMT
Does the NLL still have sub-stations? There seems to be a redundant LNWR one at the site of the old Dalston Junction station and another to the same design at Willesden Junction, while a third near West Hampstead and adjacent to the SB Met Line has disappeared in recent years.
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Post by Deleted on Mar 26, 2008 20:08:42 GMT
Most of the power supply comes in off the main line (WCML and Anglia) - though the DC is fed from Kew - the old DC substations are extant and empty - though the Willesden one is a treasure trove of old equipment and the remains of an old training school for teaching staff the principles of power isolation , paddling up shoegear etc.
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Post by david3383 on May 12, 2008 17:49:29 GMT
The answer's actually yes, almost. Trains currently use third rail Richmond-Acton Central, Camden Road-Dalston Junction and Hackney Wick-Stratford. The latter is going to disappear when the new NLL platforms at Stratford come into use at the end of the year. The Camden-Dalston section is due to be completely rebuilt for the ELL extension and the NLL service upgrade, and the tracks used by the NLL will almost certainly be overhead only (the ELL will have its own dedicated third rail tracks to get to Highbury). That means come 2011 the western section is the only place where third rail will be used, and due to the District is unlikely to change. So it won't be possible to have AC for NLL and DC for District line between Acton and Richmond? Why not? |
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Post by Deleted on May 12, 2008 18:41:56 GMT
waste of electricity, and its a bit stupid having 2 types of power supply in use and also AC freight locomotives dont really need to come south of willesden
and the whole point of 313's on the line was dual voltage purposes and new stock will be dual voltage aswell
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Post by cetacean on May 12, 2008 19:48:20 GMT
Because it would mean spending a big chunk of money to make the system electrically more complex and less reliable.
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Post by Deleted on May 12, 2008 22:47:07 GMT
They need dual voltage units as, I believe, the ELL will remain third rail. Therefore no point putting OHLE up to Richmond
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Post by Deleted on May 13, 2008 0:05:17 GMT
There is however a lot of sense in converting the remaining bits of third rail east of Willesden to 25kV AC, especially if it is combined with electrification of the remaining bits of the GOBLIN.
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Post by Deleted on May 14, 2008 19:36:19 GMT
Money is going to have to be spent in seperating the electric sections on NR where tube stock operates - Gunnersbury; Putney et al as more of the main line fleet regenerates.Southern DC units have just started for example with the 3 car Electrostars -
I dont see the point in 25kv for west of Willesden as its just a tidying up operation - and the GOB is challenged for 25kv or W10 clearance - not both !
the Pan up / down club still exists - 313114 lost one yesterday on the West London line - continued to Clapham on DC and got a tow home presumably at the end of service !
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Post by Deleted on May 22, 2008 20:54:51 GMT
I agree there, its a bit of a waste
Try having a 313 pass a 92, the power always almost shuts down every time they pass each other ,this happens even with the power hungry 377s
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Post by raakone on Jun 4, 2008 23:52:32 GMT
Try having a 313 pass a 92, the power always almost shuts down every time they pass each other ,this happens even with the power hungry 377s Ok, there's not enough power for them to do so? Does the power supply need to be improved? Or is there going to be an Ongar situation? (I read that the Epping to Ongar section of the Central line only had enough power for 2 "short" trains, and one of the stations had the bulbs dim when a train came) |
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