On Wed, 24 Oct 2012 20:24:24 +0100, "Peter Able" stuck@home wrote:


"Charles Ellson" wrote in message
.. .
On Wed, 24 Oct 2012 09:31:37 -0700 (PDT), D7666
wrote:

On Oct 24, 11:57 am, 77002 wrote:

It really IS time to hand the fast pair over to NR/Chiltern and cut
TfL back to Moor Park and Watford.- Hide quoted text -

To acheive what ?

Vary it to future upgrading in the form of 25kV from Marylebone to
Aylesbury with DC left until further notice between Harrow and
Amersham. This leaves roughly the same track availability as at
present with the opportunity for future (whole/part) conversion of the
Met to 25kV when the DC equipment is beyond saving, possible use of
joint stock (i.e. including existing stock with new transformer
coaches and new sets re-using displaced coaches from old sets). With
the Met being diverted to Watford Junction and thoughts about
extensions north of Aylesbury it would reduce the electrical
incompatibility that LU has with surrounding systems.

Stand on any up platform, Amersham to Moor Park inclusive, and observe how
few passengers use the Chiltern services

Maybe they don't all want to go where the Chiltern trains (presently)
go ?

- so upgrading Aylesbury to
Marylebone would yield no benefit to the overwhelming majority of these
thousands of passengers.

I doubt if the passengers give a damn how the juice reaches the
trains; they are more likely to notice when things go missing such as
e.g. trains from Aylesbury to Baker Street. Getting rid of running two
different systems (one non-standard) in what is practically the same
space would add to flexibility and ought to decrease potential
problems.

Likewise with the god-forsaken idea of pushing the
Met on into Watford Junction. As for the conversion of the Met to OHLE -
this is the loose sort of thinking that spawned IEP.

Distinct from the loose sort of thinking of replacing a knackered
obsolete DC ground-based supply with a brand new obsolete DC
ground-based supply system ?
It is the sort of thinking that has contributed to the greatly
increased use of the North London line.
It is the sort of thinking that seems to be under serious
consideration in SR third-rail territory.

"Charles Ellson" wrote in message
...
On Wed, 24 Oct 2012 20:24:24 +0100, "Peter Able" stuck@home wrote:


"Charles Ellson" wrote in message
. ..
On Wed, 24 Oct 2012 09:31:37 -0700 (PDT), D7666
wrote:

On Oct 24, 11:57 am, 77002 wrote:

It really IS time to hand the fast pair over to NR/Chiltern and cut
TfL back to Moor Park and Watford.- Hide quoted text -

To acheive what ?

Vary it to future upgrading in the form of 25kV from Marylebone to
Aylesbury with DC left until further notice between Harrow and
Amersham. This leaves roughly the same track availability as at
present with the opportunity for future (whole/part) conversion of the
Met to 25kV when the DC equipment is beyond saving, possible use of
joint stock (i.e. including existing stock with new transformer
coaches and new sets re-using displaced coaches from old sets). With
the Met being diverted to Watford Junction and thoughts about
extensions north of Aylesbury it would reduce the electrical
incompatibility that LU has with surrounding systems.

Stand on any up platform, Amersham to Moor Park inclusive, and observe how
few passengers use the Chiltern services

Maybe they don't all want to go where the Chiltern trains (presently)
go ?

- so upgrading Aylesbury to
Marylebone would yield no benefit to the overwhelming majority of these
thousands of passengers.

I doubt if the passengers give a damn how the juice reaches the
trains; they are more likely to notice when things go missing such as
e.g. trains from Aylesbury to Baker Street. Getting rid of running two
different systems (one non-standard) in what is practically the same
space would add to flexibility and ought to decrease potential
problems.

Likewise with the god-forsaken idea of pushing the
Met on into Watford Junction. As for the conversion of the Met to OHLE -
this is the loose sort of thinking that spawned IEP.

Distinct from the loose sort of thinking of replacing a knackered
obsolete DC ground-based supply with a brand new obsolete DC
ground-based supply system ?
It is the sort of thinking that has contributed to the greatly
increased use of the North London line.
It is the sort of thinking that seems to be under serious
consideration in SR third-rail territory.

EXACTLY the same sort of loose thinking that produced IEP. Both the Dft's
case for IEP and your argument - particularly as demonstrated in the above
paragraph - are based upon an initial premise that is completely false (Dft:
It takes over 15 minutes to attach a diesel locomotive; Yours that DC 4th
rail is a "knackered obsolete" system). You then build your case on the
sandiest of sand.

On 24 Oct, 20:24, "Peter Able" stuck@home wrote:
"Charles Ellson" wrote in message

...





On Wed, 24 Oct 2012 09:31:37 -0700 (PDT), D7666
wrote:

On Oct 24, 11:57 am, 77002 wrote:

It really IS time to hand the fast pair over to NR/Chiltern and cut
TfL back to Moor Park and Watford.- Hide quoted text -

To acheive what ?

Vary it to future upgrading in the form of 25kV from Marylebone to
Aylesbury with DC left until further notice between Harrow and
Amersham. This leaves roughly the same track availability as at
present with the opportunity for future (whole/part) conversion of the
Met to 25kV when the DC equipment is beyond saving, possible use of
joint stock (i.e. including existing stock with new transformer
coaches and new sets re-using displaced coaches from old sets). With
the Met being diverted to Watford Junction and thoughts about
extensions north of Aylesbury it would reduce the electrical
incompatibility that LU has with surrounding systems.

Stand on any up platform, Amersham to Moor Park inclusive, and observe how
few passengers use the Chiltern services - so upgrading Aylesbury to
Marylebone would yield no benefit to the overwhelming majority of these
thousands of passengers. *Likewise with the god-forsaken idea of pushing the
Met on into Watford Junction. *As for the conversion of the Met to OHLE -
this is the loose sort of thinking that spawned IEP.

I think you are saying most passengers do not want to reach
Marylebone, and its interchange with the Bakerloo line. However, the
addidion of a comprehensive interchange at West Hampstead would open
up a multitude of possible destinations.

"e27002" wrote in message
...
On 24 Oct, 20:24, "Peter Able" stuck@home wrote:
"Charles Ellson" wrote in message

...





On Wed, 24 Oct 2012 09:31:37 -0700 (PDT), D7666
wrote:

On Oct 24, 11:57 am, 77002 wrote:

It really IS time to hand the fast pair over to NR/Chiltern and cut
TfL back to Moor Park and Watford.- Hide quoted text -

To acheive what ?

Vary it to future upgrading in the form of 25kV from Marylebone to
Aylesbury with DC left until further notice between Harrow and
Amersham. This leaves roughly the same track availability as at
present with the opportunity for future (whole/part) conversion of the
Met to 25kV when the DC equipment is beyond saving, possible use of
joint stock (i.e. including existing stock with new transformer
coaches and new sets re-using displaced coaches from old sets). With
the Met being diverted to Watford Junction and thoughts about
extensions north of Aylesbury it would reduce the electrical
incompatibility that LU has with surrounding systems.

Stand on any up platform, Amersham to Moor Park inclusive, and observe how
few passengers use the Chiltern services - so upgrading Aylesbury to
Marylebone would yield no benefit to the overwhelming majority of these
thousands of passengers. Likewise with the god-forsaken idea of pushing
the
Met on into Watford Junction. As for the conversion of the Met to OHLE -
this is the loose sort of thinking that spawned IEP.

I think you are saying most passengers do not want to reach
Marylebone, and its interchange with the Bakerloo line. However, the
addidion of a comprehensive interchange at West Hampstead would open
up a multitude of possible destinations.

-----------------

Indeed they don't want Marylebone. What they want is Central London. That
said, developing West Hampstead does seem to make sense.

On Wed, 24 Oct 2012 20:02:23 +0100
Charles Ellson wrote:
present with the opportunity for future (whole/part) conversion of the
Met to 25kV when the DC equipment is beyond saving, possible use of

Brilliant idea. So who gets to rebuild the circle line tunnels so the
catenary can fit? Not to mention that unless you're planning on dual voltage
trains or re-wiring the entire circle line then it will still have to be
DC in the central section. And then of course someone will have to stick
some pantographs on the battery locomotives.

Btw, what is the cost of entirely replacing the met lines DC system and
installing 25KV including catenary? Quite a bit more than relaying some new DC
rails I suspect.

B2003

On Thu, 25 Oct 2012 10:44:49 +0100, wrote:

On Thu, 25 Oct 2012 09:12:12 +0000 (UTC), d
wrote:

On Wed, 24 Oct 2012 20:02:23 +0100
Charles Ellson wrote:
present with the opportunity for future (whole/part) conversion of the
Met to 25kV when the DC equipment is beyond saving, possible use of

Brilliant idea. So who gets to rebuild the circle line tunnels so the
catenary can fit?

Is that a certainty with the lesser clearances that are now known to
be needed ? Was there any significant rebuilding on the Widened Lines
when 25kV was installed ?

To go off on a complete tangent does any one know if the 3000 volt 3
phase system the Metropolitan railway considered would have been
straightfoward to install, or would that have required some tunnel
alterations.

So maybe conductor rail electrification was already seen as not the
way to do it back then ? ITYF the cut and cover construction of the
tunnels would at the least have given a more horizontal tunnel roof to
work with.
http://www.gracesguide.co.uk/Metropolitan_Railway
refers to (in 1900) the Met favouring OHLE and the District favouring
DC conductor rail with a tribunal recommending the DC system; in turn
the article refers to :-
http://www.localhistory.scit.wlv.ac....MetRailway.htm
although there does not seem to be specific mention of the number of
AC phases proposed.

http://www.tubeprune.com/history.html
suggests that the DC choice was influenced by Yerkes's takeover of the
District Railway.

http://www.casebook.org/victorian_lo...l?printer=true
also mentions OHLE proposals but again no specific mention of 3-phase.

Mention is made however of Ganz which IMU infers 3-phase but according
to Wonkypaedia :-
http://en.wikipedia.org/wiki/K%C3%A1...A1n_Kand%C3%B3
there was also a modified system using a single-phase OH supply with
conversion to 3-phase on the locomotive used in Hungary; the wlv.ac.uk
article referred to above mentions the "an overhead conductor" so the
Met. might only have wanted one piece of wet string.
Either way it suggests that the Met. saw OHLE as a viable proposition
without apparent mention of clearances etc. although that doesn't
inevitably mean that clearances were related to tunnel roof height
rather than locomotive/carriage roof height.

Charles Ellson wrote:
On Thu, 25 Oct 2012 10:44:49 +0100, wrote:
To go off on a complete tangent does any one know if the 3000 volt 3
phase system the Metropolitan railway considered would have been
straightfoward to install, or would that have required some tunnel
alterations.

So maybe conductor rail electrification was already seen as not the
way to do it back then ? ITYF the cut and cover construction of the
tunnels would at the least have given a more horizontal tunnel roof to
work with.


Don't forget that, in 1900, the percentage of the Underground (as
distinct from Tube) lines that were in tunnel was very small indeed.

The cut and cover tunnels were constructed on an ad hoc basis to allow
buildings to be constructed above, in a way comparable to the Gerrards
Cross Tesco project.

To go off on a complete tangent does any one know if the 3000 volt
3 phase system the Metropolitan railway considered would have been
straightfoward to install, or would that have required some tunnel
alterations.

Mention is made however of Ganz which IMU infers 3-phase but according
to Wonkypaedia :-
http://en.wikipedia.org/wiki/K%C3%A1...A1n_Kand%C3%B3
there was also a modified system using a single-phase OH supply with
conversion to 3-phase on the locomotive used in Hungary; the wlv.ac.uk
article referred to above mentions the "an overhead conductor" so the
Met. might only have wanted one piece of wet string.

No, it was two overhead wires. The following is from "A History
of London Transport" (Barker and Robbins), volume 2, pages 58
and 75. The Metropolitan and District issued a call for tenders for
electrifying their lines and hired two consultants, Sir William Preece
and Thomas Parker, to examine the tenders.

# Preece and Parker... on 9 January 1901, reported that the thought
# that Ganz's seemed the most suitable but felt that they ought to
# inspect the Ganz system before making a definite recommendation.
# They went to Budapest and reported to the joint committee on
# 7 February 1901 that they were satisfied. It was therefore
# decided to recommend the Ganz system to the two companies.
# This agreed recommendation came as a bombshell, for the Ganz
# tender was for a 3,000-volt three-phase a.c. system fed to the
# trains from two overhead wires, quite unlike anything which had
# been tried out by the underground companies so far and, indeed,
# different from anything which had been in successful commercial
# operation up to that time anywhere in the world.
...
# This had the attraction of economizing in transformer and
# converting plant but the disadvantage of requiring twin overhead
# wires with a potential difference of 3,000 volts between them
# and between each of them and earth. These overhead wires would
# be difficult to install in underground tunnels and, should either
# of them be brought down when the trains had started to run, they
# might endanger human life by fire or electric shock and would
# certainly lead to long interruptions in service. There was
# the further disadvantage that alternating current motors had
# a much poorer starting torque, a very important consideration
# on a system having numerous stations and frequent stops. And,
# most important of all, the Ganz system had not at that time been
# tried out anywhere in the world under commercial conditions,
# though it had been shown to be technically feasible on a trial
# stretch of open line about a mile long...

"Difficult to install in tunnels". That sounds to me as though
they felt there was enough clearance for 3,000-volt overhead
wiring, but only just.

Note incidentally that there was 3,000 volts between each wire and
earth as well as between the two wires. That's obviously because
the earthed running rails were to be used as the third phase, just
as they are a conductor when used with third rail (and not fourth)
or single-wire overhead. In a 3-phase system with 3 separate
conductors, they only need to be at 3,000/sqrt(3) = 1,732 volts
relative to earth to have 3,000 volts between any two of them.

The book includes a long footnote which says, among other things,
that the first use of the Ganz system in commercial service was on
the Valtellina line near Lake Como in September 1902; and that
technical details of the system and an illustration of a Valtellina
line locomotive can be found in "History of the Electric Locomotive"
(1969) by F.J.G. Haut.
--
Mark Brader, Toronto | This is Programming as a True Art Form, where style
| is more important than correctness... --Pontus Hedman

My text in this article is in the public domain.

On Oct 25, 11:51*pm, Charles Ellson wrote:

Is that a certainty with the lesser clearances that are now known to
be needed ? Was there any significant rebuilding on the Widened Lines
when 25kV was installed ?

No, but the clearances are minimal, and 319s sit lower on their
suspensions than 321s do (I guess 377/5s do comoared with other 377s
but have yet to find this data).

Some of the track was lowered by using slab track - the usual reason
stated for slab track in the tunnels is reduced maintenance - which
is of course true - but overall it is lower height than sleepered
track allowing shoe horning of OLE.




To go off on a complete tangent does any one know if the 3000 volt 3
phase system the Metropolitan railway considered would have been
straightfoward to install, or would that have required some tunnel
alterations.


That depends how you look at this.

Other statements that " xx volts" are difficult to install in tunnels
are incorrect without qualification. There is no difficulty in
installing anything in tunnels provided the tunnel is big enough, so
if you go back in time to when these ideas were proposed the
underground network was a lot smaller, and, in the case of the Met.
and Dist. that already existed far easier to have altered than today
- you don't have huger tower blocks foundations straddling the railway
making for impossible obstructions. Cut and cover lines could have
been more easily dug out then but imagine trying to do that now with
todays road traffic ... and road lobby.


I'd say if it had been done at the time it was proposed it would have
required alterations of larger extent than today because they'd need
larger clearances than todays modern insulation standards allow, and
those alterations would have been far far less disruptive than
attempting it today.

--
Nick

"77002" wrote

It really IS time to hand the fast pair over to NR/Chiltern and cut
TfL back to Moor Park and Watford.

I don't think there is any urgent need for a change, apart from the
diversion of Met trains into Watford Junction, and extending Chiltern to
Milton Keynes (via Quainton Road and Winslow). A useful add-on might be an
Amersham - Watford Junction shuttle.

But the joint running is less than perfectly efficient. There have been
previous proposals for the Met to provide all trains between Amersham and
Central London, with Aylesbury - Amersham reduced to a shuttle, or the Met
could be extended to Aylesbury (BR proposals to close Marylebone in the
early 1980s), or for a Crossrail branch across Old Oak Common to the Acton
Wells - Neasden Junction line. which would then have taken over the Chiltern
line to Harrow, the Met Fast Lines to Watford South Junction, and then whole
Amersham, Chesham and Aylesbury service.

I suspect that a recast (though not in the near future) might involve a 25
kV service from Marylebone taking over the Met Fast Lines from Harrow and
all Met services to Chesham and Amersham, but with a West Hampstead
Interchange station so that Chiltern passengers could transfer there to Met
trains to the City or Jubilee trains to the West End and Docklands.

Peter