🚀 go-pugleaf

Neil,

The long diagonal track crossing a whole formation
of other tracks, but connected to them by a series of
inbuilt turnouts, was once very popular in the UK.

The inbuilt turnouts, whether wholly inside the diamond
crossing or partly without, were called 'slip points' or
simply 'slips'.

There were single slips, for one diverging route, or double
slips for two.  Most major BR termini had loads of them
in their throats but for some reason, allegedly of cost, they
fell out of favour around 30 years ago and were progressively
removed. This was often done as part of rationalisation,
which in turn was the result of lost traffic and route reduction.

They were always subject to a low or medium speed
restriction but that didn't really matter around termini or
through stations where almost every train would stop.

Replacing slips by plain turnouts requires more room
to perform the same moves in confined spaces, but plain
turnouts are, on the other hand, easier to maintain and
repair if need be.


Regards,

Eddie.

Eddie Bellass, Mythical Merseyside, in the
Occupied Territories of Old Lancashire, UK.

Outgoing mail is certified Virus Free and checked
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On Mon, 05 Apr 2004 22:20:17 +0100, MatSav wrote:

> I wondered, for a bit of trivia - what is the "longest crossover" in
> the UK? i.e. what is the greatest number of tracks that can be
> crossed, without reversing, or on flyovers or underpasses, by a train
> diverted from the "straight" path? Is it this particular set-up at CJ?
> it seemed to me that it could be possible for a train from the
> northernmost line to divert to almost any platform at CJ. Is this the
> case?

I'm not sure, but the idea of having a single crossover (or pair thereof)
going all the way across a large number of tracks is very common on
station approaches in Europe.  Each track has some kind of "turnout" for
leaving the "diagonal track" (I don't know the proper terms).  This makes
for a *very* smooth traversal, in comparison with the UK's approach of
snaking slowly across the formation over several separate crossovers.

Neil
--
Neil Williams in Milton Keynes, UK
Mail me on neil at the above domain; mail to the above address is NOT read

"MatSav" <matthew D O T savage A T felthamscouts DOT org D O T uk> wrote in
message news:ovh370pkuj2r88at9pooogosgo3q7ehtsv@4ax.com...
> I wondered, for a bit of trivia - what is the "longest crossover" in
> the UK? i.e. what is the greatest number of tracks that can be
> crossed, without reversing, or on flyovers or underpasses, by a train
> diverted from the "straight" path? Is it this particular set-up at CJ?
> it seemed to me that it could be possible for a train from the
> northernmost line to divert to almost any platform at CJ. Is this the
> case?

Prior to electrification in the 1960's, at Rugby there was a connection from
the down goods line crossing on the level all other lines through the
station to access the branch line to Leicester. (i.e. crossing down Through,
down Platform, up Platform, up Through and up goods lines). Very
infrequently used as a consequence - in fact although there were many loaded
freight trains from the Leicester branch heading up the main line towards
London, the return empties were routed via Northampton and Market Harborough
to avoid using this crossing. Sadly, both this crossing and the Leicester
branch long since gone.
Barry P.

On Mon, 05 Apr 2004 22:31:04 GMT, "Eddie Bellass"
<eddiebellass@blueyonder.co.uk> wrote:

Eddie,

>There were single slips, for one diverging route, or double
>slips for two.  Most major BR termini had loads of them
>in their throats but for some reason, allegedly of cost, they
>fell out of favour around 30 years ago and were progressively
>removed. This was often done as part of rationalisation,
>which in turn was the result of lost traffic and route reduction.

I believe they are also quite difficult to deal with on overhead
electrified lines.

Jim.

On Tue, 06 Apr 2004 01:19:57 +0100, Jim Guthrie wrote:

> I believe they are also quite difficult to deal with on overhead
> electrified lines.

Doesn't seem a problem in Germany...

It's worth noting that they are taken at relatively high speeds there, too
- the ride is normally superb, give or take an almighty bang from the
suspension when turning into and out of them as the angle can be quite
sharp.

Neil
--
Neil Williams in Milton Keynes, UK
Mail me on neil at the above domain; mail to the above address is NOT read

On Tue, 06 Apr 2004 07:37:08 +0100, Neil Williams
<wensleydale@pacersplace.org.uk> wrote:

Neil,

>> I believe they are also quite difficult to deal with on overhead
>> electrified lines.
>
>Doesn't seem a problem in Germany...

I was told that by a BR employee when they were rebuilding the Glasgow
Central approaches in the early 60s.

Jim.

"Clive R Robertson" <hypatia@nospam.demon.co.uk> wrote in message
news:3ka570da1kaatsthd07efm2j8qj93cpodg@4ax.com...
>
> But not impossible. See the examples at Kings Cross.
>
Until J****s leave one of the bits out, in front of the 0700 to Edinburgh.
Peter

On Tue, 06 Apr 2004 01:19:57 +0100, Jim Guthrie <jim@sprok01.plus.com>
wrote:

>On Mon, 05 Apr 2004 22:31:04 GMT, "Eddie Bellass"
><eddiebellass@blueyonder.co.uk> wrote:
>
>Eddie,
>
>>There were single slips, for one diverging route, or double
>>slips for two.  Most major BR termini had loads of them
>>in their throats but for some reason, allegedly of cost, they
>>fell out of favour around 30 years ago and were progressively
>>removed. This was often done as part of rationalisation,
>>which in turn was the result of lost traffic and route reduction.
>
>I believe they are also quite difficult to deal with on overhead
>electrified lines.
>
>Jim.

But not impossible. See the examples at Kings Cross.

Regards,

Clive

--
Clive R Robertson -- AS/400 Programmer.

Webmaster of http://www.osterleypark.org.uk/ -- this describes
a beautiful National Trust property in West London.

"Jim Guthrie" <jim@sprok01.plus.com> wrote in message
news:0em470taeat1835t9s6qg107q3495ltrhl@4ax.com...
> On Tue, 06 Apr 2004 07:37:08 +0100, Neil Williams
> <wensleydale@pacersplace.org.uk> wrote:
>
> Neil,
>
> >> I believe they are also quite difficult to deal with on overhead
> >> electrified lines.
> >
> >Doesn't seem a problem in Germany...
>
> I was told that by a BR employee when they were rebuilding the Glasgow
> Central approaches in the early 60s.

Similar thing with Newcastle - when it was wired up around 1990/1991, the
famous "Diamond Crossing" arrangement north of the station had to be taken up
and replaced with a much simpler layout to simplify the OHL.

--
*** http://www.railwayscene.co.uk/ ***
Updating regularly throughout 2004
Rich Mackin (rich-at-richmackin.co.uk)

In article <DNDcc.332$DB.44@newsfe1-win>, Rich Mackin
<rich@richmackin.SPAMTRAP.co.uk> writes
>Similar thing with Newcastle - when it was wired up around 1990/1991, the
>famous "Diamond Crossing" arrangement north of the station had to be taken up
>and replaced with a much simpler layout to simplify the OHL.

I don't think it was the OHLE that was the problem; rather, that
junction was a major pain to maintain - every single rail crossing (and
each diamond consisted of four such) was at a different angle.

--
Clive D.W. Feather, writing for himself  | Home: <clive@davros.org>
Tel: +44 20 8495 6138 (work)             | Web:  <http://www.davros.org>
Fax: +44 870 051 9937                    | Work: <clive@demon.net>
Written on my laptop; please observe the Reply-To address

Clive D. W. Feather wrote:
> In article <DNDcc.332$DB.44@newsfe1-win>, Rich Mackin
> <rich@richmackin.SPAMTRAP.co.uk> writes
>
>> Similar thing with Newcastle - when it was wired up around 1990/1991, the
>> famous "Diamond Crossing" arrangement north of the station had to be
>> taken up
>> and replaced with a much simpler layout to simplify the OHL.
>
>
> I don't think it was the OHLE that was the problem; rather, that
> junction was a major pain to maintain - every single rail crossing (and
> each diamond consisted of four such) was at a different angle.
>

I'm not *absolutely* sure about all of this, but I think the previous
diamond arrangement at Newcastle also required gaps in the track
circuits.  As the angle of a diamond crossing approaches 90 deg., PW
constraints make the fitting of insulated joints in the required
positions increasingly problematic, so there comes a point where track
circuits have to 'jump' over the crossing, at least on one road.  I
think it was these gaps which were the reason for the Class 03
shunters here being 'permanently' coupled to a 'match' wagon to
increase their effective length so they didn't get lost in a 'black
hole'.  Clearly such gaps are best avoided, so this might have been a
factor in the removal of the diamonds when the new signalling was
being planned, although the PWE would certainly have wanted rid of
them as well.

I have seen many instances on old signalling plans where track
circuiting was 'jumpered' around crossings, and of shallower angles
than Newcastle too.  This presumably had something to do with
different PW standards or methods of manufacture available at the
time.  Whatever the reason, there was a programme on the LM to
eliminate such gaps wherever possible, beginning in the 1960s, though
I think I've seen cases which remained into the early-mid 70s.


Wobbly Bob

In article <407878D3.900@btinternet.com>, Wobbly Bob
<never.read@btinternet.com> writes
>>> famous "Diamond Crossing" arrangement north of the station had to be
>>>taken up
>>> and replaced with a much simpler layout to simplify the OHL.
>>   I don't think it was the OHLE that was the problem; rather, that
>>junction was a major pain to maintain - every single rail crossing
>>(and  each diamond consisted of four such) was at a different angle.
>I'm not *absolutely* sure about all of this, but I think the previous
>diamond arrangement at Newcastle also required gaps in the track
>circuits.

I find this very plausible as well.

It looks like, pretty as the multiple diamonds may have looked, they
were a Bad Thing for all kinds of reasons.

--
Clive D.W. Feather, writing for himself  | Home: <clive@davros.org>
Tel: +44 20 8495 6138 (work)             | Web:  <http://www.davros.org>
Fax: +44 870 051 9937                    | Work: <clive@demon.net>
Written on my laptop; please observe the Reply-To address

"Clive D. W. Feather" <clive@on-the-train.demon.co.uk> wrote:

> In article <407878D3.900@btinternet.com>, Wobbly Bob
> <never.read@btinternet.com> writes
> > > > famous "Diamond Crossing" arrangement north of the station had to be
> > > > taken up and replaced with a much simpler layout to simplify the
> > > > OHL.
> >>   I don't think it was the OHLE that was the problem; rather, that
> > > junction was a major pain to maintain - every single rail crossing
> > > (and  each diamond consisted of four such) was at a different angle.
> > I'm not *absolutely* sure about all of this, but I think the previous
> > diamond arrangement at Newcastle also required gaps in the track
> > circuits.
>
> I find this very plausible as well.
>
Yes, this would explain why the 03 shunters running around the place had
flat waggons coupled to them as they couldn't be relied upon to work the
track circuits reliably themselves.

> It looks like, pretty as the multiple diamonds may have looked, they were
> a Bad Thing for all kinds of reasons.
>
I once heard that the diamond crossing at Newcastle was where a reliable
method for welding manganese steel was first devised and used.

"Clive D. W. Feather" <clive@on-the-train.demon.co.uk> wrote in message
news:R+$jWfXzdGeAFwKN@romana.davros.org...

> I don't think it was the OHLE that was the problem; rather, that
> junction was a major pain to maintain - every single rail crossing (and
> each diamond consisted of four such) was at a different angle.
>
> --
> Clive D.W. Feather, writing for himself  | Home: <clive@davros.org>

Wasn't the main reason that the diamond was redundant since the effective
closure of the suburban part of the Central Station.  Access to the terminus
platforms from South Shields across the High Level Bridge had ceased,  due
to the Metro, and  trains from Sunderland now run to the new island platform
5,6,7 & 8 south of the 3 main through platforms 2, 3 & 4 towards King Edward
Bridge and the west via Dunston.  Current platform 1 is the only east facing
bay and AFAIK is only used for local trains from the Morpeth direction
terminating at Central.

Paul Scott

"MatSav <matthew D O T savage A T felthamscouts DOT org D O T uk>"
<MatSav> wrote in message
news:ovh370pkuj2r88at9pooogosgo3q7ehtsv@4ax.com

I'll try again as I think a post got lost.

> Platform 11 (or thereabouts) - and I noticed that there appeared to be
> what I would call a "crossover", or joined sets of points, that showed
> a possible route right across to the northernmost track in the
> distance (the Kenny O. chord?)

>  Is it this particular set-up at CJ?
> it seemed to me that it could be possible for a train from the
> northernmost line to divert to almost any platform at CJ. Is this the
> case?

Not exactly.

It is a physical route across those crossings but not a running line.

What you have seen is the exit from Clapham Yard, or carriage sidings or
whatever it is called these days, that has one connection into the yard
off the Up main Loop (I think).

None of this is suitable for passenger trains and is only used by empty
trains. It has to my knowledge never been a running line and theres is
no such running connection between the Main and Windsor lines, as the
points in question are part of a group of sidings. If you look at the
signals there are no route indicators for signalling such a route. Most
of the signals where fitted are ground level shunt signals [which does
not in otself exclude running movements] and IIRC a number of the points
are hand operated [which does].

--
Nick








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