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.

"Bruce" wrote


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.

Most of the original Met (Paddington to Farringdon) was built under streets,
which were reinstated after construction of the railway. The District,
between Westminster and Blackfriars, was built as part of the Victoria
Embankment project which also incorporated the river wall, the road, and
Bazalgette's sewer.
http://www.historytoday.com/roger-hudson/taming-thames

Peter

In article ,
Peter Masson wrote:


"Bruce" wrote


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.

Most of the original Met (Paddington to Farringdon) was built under streets,
which were reinstated after construction of the railway. The District,
between Westminster and Blackfriars, was built as part of the Victoria
Embankment project which also incorporated the river wall, the road, and
Bazalgette's sewer.
http://www.historytoday.com/roger-hudson/taming-thames

Indeed, even the bored tubes were mostly constructed under streets, as the
need for underground wayleaves and the risk of even the slightest damage
to property made it impossible to get Acts through parliament otherwise.

I CBA to go through "Lost Tube Schemes" in fact I can't even find it
right now (it's lost ). But until the Metroland project came along
there were few if any underground railway proposals for areas that were
not already built up - why would there be, there'd be no traffic for them!

Nick
--
"The Internet, a sort of ersatz counterfeit of real life"
-- Janet Street-Porter, BBC2, 19th March 1996

On Oct 26, 9:29*am, "Peter Masson"
wrote:
"Bruce" *wrote



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.

Most of the original Met (Paddington to Farringdon) was built under streets,
which were reinstated after construction of the railway. The District,
between Westminster and Blackfriars, was built as part of the Victoria
Embankment project which also incorporated the river wall, the road, and
Bazalgette's sewer.http://www.historytoday.com/roger-hudson/taming-thames

They were very few buildings over Met. Ry tracks. In some instances
their own station buildings spanned the tracks.

Indeed, rather than building over the tracks, their is the instance of
a dummy facades in the Paddington area, i.e. 23 and 24 Leinster
Gardens.

Great Portland Street Station presents an interesting case. I think
the line must slice the corner as Marylebone Road becomes Euston
Road. The station entrance is at the top of Great Portland Street on
an island to the side of Euston Road. At the Western End of the
platforms there is an opening for locomotive exhaust to escape. The
protective walls around the gap are at the side of the ISH parking
lot.

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.

Mark Brader:
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.

Looking around on the Web for photos showing such a locomotive,
I only find this one, although it's on several web pages:

http://en.wikipedia.org/wiki/File:Ka...an_mozdony.jpg

So I suspect it's the same one as in Haut's book. Anyway, the
interesting thing is the collector that contacts the overhead wires,
which looks more like a big bow collector than anything else --
one collector contacting both wires. Obviously there must have
two separate contacts on that horizontal bar, with insulation
between them.

Also note how high the arm is above the locomotive. You'd never
fit that thing into a Metropolitan or District tunnel. They must
have had a different sort of collector in mind.

This page shows that photo and a couple of other ones of the Ganz
3-phase system, before moving on to related subjects. They all
appear to have those high collectors.

http://erojr.home.cern.ch/erojr/cont...pe/kanprot.htm
--
Mark Brader, Toronto | "What Europe needs is a fresh, unused mind."
| -- Foreign Correspondent

My text in this article is in the public domain.

On Oct 26, 11:22*pm, (Mark Brader) wrote:

one collector contacting both wires. *Obviously there must have
two separate contacts on that horizontal bar, with insulation
between them.


Also note how high the arm is above the locomotive. *You'd never
fit that thing into a Metropolitan or District tunnel. *They must
have had a different sort of collector in mind.


I've never really looked into the three phase ideas of the Met but I'd
always thought they were looking at the three phase "two wire" system
(i.e. three phases of two conductors and one running rail return) not
with overhead wires but rails, with lower supply voltage than Ganz.
Conductor rails something like the centre and outer rail (like todays
DC) would be the equivalent to Ganz two wires, and the running rails
the return in the same way as Ganz. That way you don't need to expand
tunnels. My interpretation of "not suitable for tunnels" was not
something about not enough wire clearances but one of having all
track rails in a three phase system at a voltage too high for exposed
ground level conductors. Like I said its not something I looked into,
so maybe I misunderstood the whole thing.

If you really wanted to run three phase for the tubes I suggest you
simply use a side contract pickup for all three phases - its complex
at points and crossings but providing one car of the set is in contact
you still have power, and thats no different to a lot of DC section
gaps on todays tube.

--
Nick

Mark Brader:
Also note how high the arm is above the locomotive. You'd never
fit that thing into a Metropolitan or District tunnel. They must
have had a different sort of collector in mind.

"Nick":
I've never really looked into the three phase ideas of the Met but I'd
always thought they were looking at the three phase "two wire" system
...not with overhead wires but rails, with lower supply voltage than Ganz.

As I indicated in my previous posting, "A History of London Transport"
is quite explicit that it was Ganz and overhead wires.
--
Mark Brader, Toronto | "Something doesn't become ethical just because
| you can get away with it." --Barry Margolin

On Sat, 27 Oct 2012 01:52:33 +0100, wrote:

On Fri, 26 Oct 2012 17:22:33 -0500, (Mark Brader) wrote:

Mark Brader:

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.

Looking around on the Web for photos showing such a locomotive,
I only find this one, although it's on several web pages:

http://en.wikipedia.org/wiki/File:Ka...an_mozdony.jpg

So I suspect it's the same one as in Haut's book. Anyway, the
interesting thing is the collector that contacts the overhead wires,

Also note how high the arm is above the locomotive. You'd never
fit that thing into a Metropolitan or District tunnel. They must
have had a different sort of collector in mind.

Bonnet mounted collectors have been used on some electric locos where
there were limited clearances.
http://www.flickr.com/photos/45127721@N05/6581147453
is an example on a UK industrial system that survived till the late
1980's.
In a tunnel setting arcing from such a low collector in the drivers
view can cause disruption to vision and I shouldn't think it would do
much for the health of the eyes either.

That can be avoided by using the rear collector if two are fitted as
on the Italian locomotives in :-
http://en.wikipedia.org/wiki/Three-p...lectrification

On the subject of Italy, I hadn't realised they were still using
3-phase into the 1970s :-
http://www.photorail.com/phr1-leFS/e432.htm
(with an interesting effect caused by smoke/steam/fumes coming from a
"chimney" at one end)

Trolley poles would be another possibility. Used in the original
Cascades tunnel electrification in the United States which was a 3
phase system.

Distance memory's of trolley buses and dewirements suggest they would
be impractical on a system with many junctions like the Metropolitan
even though a railed vehicle would have less tendency to pull the
booms offline.

G.Harman