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electrified 3rd rail and non electrified 3rd rail


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  • RMweb Gold

Hi All, 

 

on the 3rd rail network, (apart from reading) are there any stations which had electrified and non electrified platforms, and are there any examples of non electrified lines and electrified lines running together for a considerable distance?

 

Im looking at options for putting 3rd rail down on my freelance network southeast themed layout. But id rather not do the whole layout :)

 

Thanks

 

Simon

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Euston to Watford although in the period when the mail line was not electrified the DC would have been 4 rail all the way to Watford Junction, not just to Harrow and Wealdstone as it is now. With from there to Watford Junction now being 3 rail, although most of the old 4th rail remains in the four foot as it is allegedly still needed for traction return purposes.

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Posted (edited)

Not sure that there were any such locations in the South East these days, mainly because non 3rd rail routes are in the minority so - it makes sense to fit everything.

 

That said, though in the 1920s through to the 1950s you would probably have had such a situation in certain places between phases of 3rd rail expansion - for example say the Weybridge platforms at Water having con rail but not the Reading lines (till the later got electrified in the late 1930s)

 

Up in Merseyside however you have a number of stations where only one or two tracks have con rail - Ellesmere Port and Hunts Cross spring to mind. These compare with the likes of Reigate where everything has got 3rd rail in the station  even though electrics must turn back there.

Edited by phil-b259
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  • RMweb Gold

If you count LT lines there is The Central Line section from Acton to West Ruislip with its adjacent National Rail lines, including Greenford Station with the link to Ealing Broadway.  There is also the Metropolitan Main Line with the adjacent NR lines from Marylebone.

 

Cheers

 

Darius

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30 minutes ago, Trog said:

Euston to Watford although in the period when the mail line was not electrified the DC would have been 4 rail all the way to Watford Junction, not just to Harrow and Wealdstone as it is now. With from there to Watford Junction now being 3 rail, although most of the old 4th rail remains in the four foot as it is allegedly still needed for traction return purposes.

Four rail to Watford dates back to when the Bakerloo went through to Watford, every bit of stock operated by LUL needs a 4th rail for traction current return purposes, no stock ever operated by BR (except the tube stock on the drain and the Island Line) sends return current through a running rail. Any redundant 4th rail still in place north of Harrow is only there because nobody bothered to lift it, it's broken/misaligned and not connected to anything.

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  • RMweb Gold

Thanks melmoth but that's way outside my time period sadly mid 80s to mid 90s looks like whole layout it is....

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1 minute ago, pheaton said:

Thanks melmoth but that's way outside my time period sadly mid 80s to mid 90s looks like whole layout it is....

 

Unfortunately, if you are looking at NSE days then you won't find anywhere that meets your requirements!

 

By the mid 1980s any new con rail schemes (with the exception of Weymouth and East Grinstead) were basically infill jobs. At eaxh end they connected into much earlier schemes were 3rd rail coverage was extensive.

 

To see a 'minimalist' 3rd rail scheme you need to look at Merseyrail - the extension to Ellesmere Port for example was very much done under the 'do minimum' mentality* and as a consequence only one platform got con rail where as were the scheme done in the 1960s no doubt both platforms would have been treated.

 

 

* 'Do minimum' is what gave use OLE only suitable for EMUs via Cambridge, only enough con rail power for single 442 units west of Poole, etc

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6 minutes ago, bigherb said:

Got a feeling the bay platform at Oxted for the Uckfield trains is not electrified.

 

Yes you are correct - but as the diesel service traditionally played second fiddle to the electrics on the Grinstead route, the rest of the station has con rail.

 

I get the impression that pheaton is looking at the reserve as it were (i.e. just a single electrified bay with the other lines being diesel.

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13 minutes ago, phil-b259 said:

To see a 'minimalist' 3rd rail scheme you need to look at Merseyrail - the extension to Ellesmere Port for example was very much done under the 'do minimum' mentality* and as a consequence only one platform got con rail where as were the scheme done in the 1960s no doubt both platforms would have been treated.

 

Also on Merseyrail, Chester station has just one end of one platform equipped with 3rd rail, all other services being diesel, although it is not far until the electrified route diverges from the main line to Holyhead.

 

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  • RMweb Gold

As his station is freelance, it seems to me that all he needs is some sort of precedent and Horsted Keynes provides that.

 

Kensington Olympia had four-rail electric into one bay (more previously) but it's not beyond the bounds of imagination to think that the Southern could have electrified the Clapham Jct to Olympia shuttle.

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Hi,

 

To add to Phil-b259 and caradoc's information on the Merseyrail network you could also look at such places as, Rock Ferry and Bidston on the Wirral lines; at the other end of the system you have Southport.  IIRC, at one time, the electrics stopped at Rock Ferry requiring you to change to a diesel service on to Ellesmere, and Chester.

 

Hope that's of use.

 

Regards,

 

Alex.

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46 minutes ago, fiftyfour fiftyfour said:

Four rail to Watford dates back to when the Bakerloo went through to Watford, every bit of stock operated by LUL needs a 4th rail for traction current return purposes, no stock ever operated by BR (except the tube stock on the drain and the Island Line) sends return current through a running rail. Any redundant 4th rail still in place north of Harrow is only there because nobody bothered to lift it, it's broken/misaligned and not connected to anything.

Just to correct you on this information the when BR replaced the trains on the Watford to Euston line, the class 501s were delivered to use 4th rail, with both positive and negative supply shoes fitted.

 

During the restoration survey work on 501DT (75186) it was found that she still had the cross beams and supports for the center contact shoe.

 

Andrew 

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  • RMweb Gold
Posted (edited)

You could look at St Denys on the outskirts of Southampton.  That might fit your timescale.

 

The non-third rail route to Fareham, which used platforms 3 and 4, were generally operated by class 205 (2H and 3H DEMUs for those of a slightly older generation), although there were also loco hauled services along the route too on the services from Portsmouth Harbour to Bristol TM and Cardiff.   The lines through those platforms didn't have con rail installed until the 'Solent Link' electrification project in the late 1980s.  The scheme was completed in May 1990.

 

Platforms 1 and 2 at St Denys had con rail installed as part of the 'Bournemouth Electrification' project along the south west main line in the mid 1960s.  

Edited by 4630
to add further info.
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  • RMweb Gold
7 minutes ago, melmoth said:

Has anyone mentioned Reading yet? Bays at the east end for the Waterloo service.

yeah me in the OP when I said "apart from reading" :) reason being I knew these lines branched off where I can't do that in my large tail chaser sadly :) 

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Is the Bay platform (5) at Basingstoke electrified, I used to remember that the DEMUs from Reading coming in to the bay and those lines which were not electrified. It used to be a straight though platform but was cut back so that the station had better access from the northside. 

 

Andrew

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2 hours ago, fiftyfour fiftyfour said:

Four rail to Watford dates back to when the Bakerloo went through to Watford, every bit of stock operated by LUL needs a 4th rail for traction current return purposes, no stock ever operated by BR (except the tube stock on the drain and the Island Line) sends return current through a running rail. Any redundant 4th rail still in place north of Harrow is only there because nobody bothered to lift it, it's broken/misaligned and not connected to anything.

 

Rubbish.

 

The LNWR North London DC Electrification was all four rail, with LNWR, LMS and BR stock up to and including the 501units all using both the Possie and Neggie conductor rails. Sometime around the ~the 1970's the 501 stock was modified to return current through the running rails, and the fourth rail was bonded to what had became the traction return running rail. So instead of carrying a tube style -ve voltage it became an alternative earth. Serving to connect the neggie shoe on LT units to the traction return rail and to strengthen the traction return path by paralleling the traction return running rail.

 

Once LT trains stopped running north of Harrow the only use of the neggie rail between there and Watford was to parallel the traction return, this is quite interesting. With the Electrical Engineers insisting that this is still necessary. However many years ago one of the Civil Engineers Technical staff, seeing the state and lack of bonding on the 'disused' neggie rail loaded about a mile of it on both roads away for scrap. The Electrical Engineers staff were not impressed by this and demanded its replacement, so some corroded old CWR recovered from Kilsby Tunnel was dropped into the four foot to replace it.

 

Some fifteen years later yours truly was doing some track relaying nearby and asked if with the improved return path offered by the larger cross-section and lack of joints in the new CWR track I was installing, the old neggie rail which was seriously corroded and had only been made up from approx. 15' 105lb rails tack welded together when it was new could be dispensed with. Ohh no said the Electrical Engineers it is vital we keep it and we can not do without it. I said fair enough I just thought I would ask as the section where the FB rail was dropped to replace the removed section of neggie rail has presumably not given any trouble since you have still not got round to bonding it up after fifteen years. They must have been straight out there as bonding appeared virtually overnight, and muggins and staff had to faff about removing and replacing a conductor rail so frail that it would snap if you even looked at it too hard.

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That leaves me wondering when the local EPME last reviewed his circuit breaker protection settings. Using the redundant fourth rail to parallel the traction return rail (in addition to the cross bonding that there should be between the traction return rails on the up and down lines) isn't strictly essential to make the trains run, but it does have an effect on the return voltage drops and the fault currents, especially if a section is single end fed. Take it away and although the trains will still run, the return impedance, and thus volt drop, goes up. The fault currents come down, making it potentiall difficult to discriminate between a far end short circuit and a train drawing full load current. Too much volt drop and in a short circuit sitation the traction negative to earth voltage can exceed the limits that are defined in standards (both NR and BS EN) as being dangerous.

 

I am assuming that the track circuits are all of the single rail type, as they would have been with four-rail electrification - conversion to two rail circuits, as could have happened, allows both running rails to be used for return current and renders the old fourth rail effectively redundant.

The other assumption that I am making is that the DC negative return rail is not connected to earth, as is standard practice with third rail electrification. It would, when the fourth rail was in proper use, have been connected to earth (just as it is with the neighbouring AC electrification, and still is in the Euston area where both DC and AC share the same tracks.

 

Jim

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There was, shall we say, some overlooking of the essentials of DC protection on the Watford Lines in the 1980s. There was an incident that was nasty, but could have been very nasty indeed, resulting from incorrect adjustment of DC breakers resulting from a serious misunderstanding of how the particular design works, plus all the -ve bonding and rail-corrosion problems that Trog mentions.
 

It’s a period that a veil is best drawn over.

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43 minutes ago, Trog said:

 

Rubbish.

 

The LNWR North London DC Electrification was all four rail, with LNWR, LMS and BR stock up to and including the 501units all using both the Possie and Neggie conductor rails. Sometime around the ~the 1970's the 501 stock was modified to return current through the running rails, and the fourth rail was bonded to what had became the traction return running rail. So instead of carrying a tube style -ve voltage it became an alternative earth. Serving to connect the neggie shoe on LT units to the traction return rail and to strengthen the traction return path by paralleling the traction return running rail.

 

 

 

Interesting to hear when the 4th rail was last used.

I have some old photos in a book about the Euston-Watford line showing South Hamsptead & Kilburn High Road with 4th rail (but it isn't there now) so I assumed this must also have continued to Euston.

When did it get lifted south/east of Queen's Park?

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