Page 2 of 3

Re: "3rd rail no longer feasible"

Posted: 14 Jul 2011 23:02
by Kevo00
Well:

a) Why are you all getting excited over something that will probably never happen in our lifetimes? Path dependence and all that...

b) It would actually make sense in the long run as the Southern Region model was traditionally to make stock for its own purposes. But now 3rd rail land is no longer special and must buy the same generic off the shelf stock converted from 25kv like everyone else...which is why they have had to increase the number of sub stations etc. Way back in the early 1970s the Tyneside electrics were replaced by DMUs before the Metro replaced them, because DMUs were more standard for the North Eastern Region than running a few EMUs. Similar with the Bury line and Metrolink. Might be interesting to see what happens on Merseyrail when the stock needs replaced - or will they keep going forever like the EMUs on the Bury line?

Re: "3rd rail no longer feasible"

Posted: 14 Jul 2011 23:38
by Geo Ghost
Dave W wrote:Ah but it looks like you've said that 3rd rail has a lower speed than OHLE, excluding HS1... Suggesting you mean HS1 is 3rd rail and is an exception. Since HS1 has a higher speed than 3rd rail anyway, the brackets were really not necessary haha.
Ah bugger it. I really need to read back my posts more thoroughly. And stop posting when tired (like that'll ever happen).
But anyway, yes I did ask if I was correct in thinking that 3rd rail is slower than most OHLE. Ignore the HS1 bit as I can see where the confusion came in with that.

Re: "3rd rail no longer feasible"

Posted: 15 Jul 2011 00:22
by JamieLei
Nonetheless, does anyone know anywhere else in the world where 3rd rail reaches 100? As far as I know (and I'm probably wrong cause I was about the MML), third rail is predominantly used for metros and doesn't reach above 60mph very much.

Re: "3rd rail no longer feasible"

Posted: 15 Jul 2011 00:46
by oberhümer
Only place I can think of is the New York City area (Metro-North/Long Island Railroad).

Re: "3rd rail no longer feasible"

Posted: 15 Jul 2011 07:42
by Dave
Can't think of anywhere really where third rail is used in massive quantities.

UK, US... Where else is it used heavily? Anywhere?

Re: "3rd rail no longer feasible"

Posted: 15 Jul 2011 12:04
by 61653
True enough, other than metro systems I can only think of a few isolated systems in Europe (http://en.wikipedia.org/wiki/Yellow_train) for example.

Re: "3rd rail no longer feasible"

Posted: 15 Jul 2011 17:34
by insulfrog
Many of the 'subway/elevated' type rail systems use either a 3rd rail or a 4th rail due to the limited clearance above the trains. Most are normally maintained and ran by independant companies from the national/main railway systems so may not be affected by the changes.

There are only a few exeptions though, some parts of the national/main railway systems which does require a 3rd rail simply because of limited 'headroom'. An example of this is the Moorgate Line in London (UK) which runs from Drayton Park to Moorgate.

If the desicion to convert from 3rd rail to overhead wires goes ahead, bridges will have to be raised and make tunnels taller to make room for the wires. That will make the conversion quite expensive overall and may have to abandon the idea as a result.

Re: "3rd rail no longer feasible"

Posted: 15 Jul 2011 17:50
by JamieLei
Lots of heavy rail metros nowadays tend to use overhead centenary though. It's rather common in Japan, the Delhi Metro is, and the entire RER system too. Singapore used Overhead for the North East Line, but then reverted back to 3rd rail for the newly-opened Circle Line for some reason...

Re: "3rd rail no longer feasible"

Posted: 15 Jul 2011 22:31
by Dave
insulfrog wrote:Many of the 'subway/elevated' type rail systems use either a 3rd rail or a 4th rail due to the limited clearance above the trains. Most are normally maintained and ran by independant companies from the national/main railway systems so may not be affected by the changes.

There are only a few exeptions though, some parts of the national/main railway systems which does require a 3rd rail simply because of limited 'headroom'. An example of this is the Moorgate Line in London (UK) which runs from Drayton Park to Moorgate.

If the desicion to convert from 3rd rail to overhead wires goes ahead, bridges will have to be raised and make tunnels taller to make room for the wires. That will make the conversion quite expensive overall and may have to abandon the idea as a result.
Could lower track level.

Re: "3rd rail no longer feasible"

Posted: 16 Jul 2011 00:42
by LaSeandre
This seems relevant.

http://www.bbc.co.uk/news/uk-england-yo ... e-14143032

Seems some ignorant publicity-hungry politician has come out saying they want this to happen, without even thinking of consulting anyone in the industry, which is a shame. Still, it would never happen now, since new 3rd and 4th rail installations are banned.

Re: "3rd rail no longer feasible"

Posted: 16 Jul 2011 03:12
by JamieLei
Haha - actually not a bad idea!
The use of these trains would mean electrifying the line - but not with the overhead power cables used elsewhere.

The power would come from a rail mounted a couple of feet above the track and a "current collector" would run along it, feeding electricity to the trains' motors.
Had to laugh at that though!

Edit: A far more accurate report:

http://www.railnews.co.uk/news/general/ ... ation.html

Re: "3rd rail no longer feasible"

Posted: 16 Jul 2011 08:19
by Ploes
You are right JamieLei, that does make far more sense.

I didn't think new covered third rail installations were banned? or is that point of this whole thread relating Railway Magazine.

Whats the issue with just doing overhead at 750vDC? Tyne and Wear metro use it at 1500DC, and then its over head with no need for transformers on the trains? How hard would it be to put pantograph on D-Stock?

Does overhead using DC need more substations than third rail at DC at the same voltage?

Re: "3rd rail no longer feasible"

Posted: 16 Jul 2011 11:43
by Kevo00
Lol, surely the district line stock is quite heavy and probably expensive to run. I do love the railway pipe dreams that surface every now and then.

If they did have to raise bridges to OHLE the Southern Region, at least they could take the chance to also raise the loading gauge to put in the much desired double decker trains, Sydney style.

Re: "3rd rail no longer feasible"

Posted: 16 Jul 2011 12:40
by Dave
Ploes wrote:How hard would it be to put pantograph on D-Stock?
Impossible.

Re: "3rd rail no longer feasible"

Posted: 16 Jul 2011 13:41
by supermop
I have to say that as a former Harrogate resident, I would love to see better service on this line, maybe even electric. I thought that LU stock had lower floors and thus lower platforms though - making it incompatible with platforms for regular DMUs - or am I wrong? I do realize that there are multiple sizes / form factors for different LU lines, so maybe this stock is more similar to a regular British train?

When I lived in Harrogate, we had those DMUs that were the most pathetic ones in service I think. I think they are what you guys call a 'pacer', and I assume that a line like this is still using them. Surely enough other lines have been getting rid of these units as they receive better trains, that they could just give a ton of surplus pacers to the Harrogate line. I would assume that labour cost, not lack any units whatsoever, is a more likely reason for the schedule being so sparse - if their are willing to put in 3rd rail and use old Underground stock, surely there are some mainline DMUs somewhere in the country that would make more sense to use.

Best,

Re: "3rd rail no longer feasible"

Posted: 16 Jul 2011 15:49
by Ploes
supermop wrote:I do realize that there are multiple sizes / form factors for different LU lines, so maybe this stock is more similar to a regular British train?
The S Stock that is replacing D Stock on the District, is also being used on the Metropolitan which shares track space with Chiltern Railways Service, so it must have a normal platform height.

Re: "3rd rail no longer feasible"

Posted: 16 Jul 2011 16:23
by Badger
supermop wrote: When I lived in Harrogate, we had those DMUs that were the most pathetic ones in service I think. I think they are what you guys call a 'pacer', and I assume that a line like this is still using them.
You're referring to the 141s, all withdrawn from service thank god, though some were sold abroard and others preserved!
Most Harrogate services ar combinations of 155, 153, 158, 144 or 150/2.

Re: "3rd rail no longer feasible"

Posted: 16 Jul 2011 16:40
by supermop
I lived in Harrogate (actually Pannal) from 1997-1999, if that helps place the units in use at that time. I remember once riding a Sprinter (was there a super sprinter?) to Manchester Airport, and being blown away at how much nicer it was.

To the point though: it seems there would be a few more of the DMUs currently serving the line available somewhere as new electrification makes nicer DMUs redundant elsewhere. Are DMUs really in such short supply that its worth electrifying the line with non standard supply just to use a handful of 3rd rail EMUs that happen to be around?

Re: "3rd rail no longer feasible"

Posted: 16 Jul 2011 21:31
by 61653
supermop wrote:I lived in Harrogate (actually Pannal) from 1997-1999, if that helps place the units in use at that time. I remember once riding a Sprinter (was there a super sprinter?) to Manchester Airport, and being blown away at how much nicer it was.

To the point though: it seems there would be a few more of the DMUs currently serving the line available somewhere as new electrification makes nicer DMUs redundant elsewhere. Are DMUs really in such short supply that its worth electrifying the line with non standard supply just to use a handful of 3rd rail EMUs that happen to be around?
That would have been a 158 (a NorthernSpirit/Arriva Transpennine one at that- one of the better examples of the refubished ones) They're fairly common on the Harrogate line now, though not quite as well-appointed, unless it's a 3-car unit as the the centre-cars still have the extra seat padding from the TPE days.

The ex-LU stock idea seems flawed though- I can't imagine Harrogate passengers being down with having no toilets (although my experience of Northern lately has not guaranteed a working toilet, even though all their units do have them fitted). A far better idea would be to electrify at 25kv overhead, at least as far as Harrogate or Knaresborough, and use existing EMUs- 321s displaced from GN would be ideal as Northern already runs similar units, and this would allow EC to run IC225 sets to Harrogate. Seeing as the North is unlikely to recieve new trains, the 332s from Heathrow Express would be suitable, as these (a) could be replaced by Desiros which would give HEx a uniform fleet, and (b) would be interoperable with 333s on the Airedale/Wharfedale lines- But then the whole idea of using LU stock highlights the complete lack of joined-up thinking in British transport policy/planning. *sigh*

Re: "3rd rail no longer feasible"

Posted: 16 Jul 2011 21:34
by Geo Ghost
Ploes wrote:so it must have a normal platform height.
Doubt it. Part of the Bakerloo line shares with London Overground. You have to step down into the train or step up out of it.
This is of course, assuming you are referring to the height of the trains doors and not the platform itself.