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.

"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.

On Oct 26, 10:09*am, "Peter Able" stuck@home wrote:
"Peter Masson" wrote in message

...







"Jeremy Double" *wrote in message
...

Denis McMahon wrote:
On Thu, 25 Oct 2012 09:28:58 +0100, Peter Able wrote:

Dft: It takes over 15 minutes to attach a diesel locomotive.

I've never understood this. If the diesel loco is properly designed to
interwork with the unit(s) that it's expected to haul, then surely
(de)coupling should take no longer than splitting and combining any *MU
stock.

In the days of ETH-fitted Peaks on the Midland main line, they used to
reverse some trains at Nottingham in 5 minutes or so, and this included
uncoupling a loco at one end of the train and coupling another one on the
other end.

Time was when 2 minutes were allowed to detach Sarah Siddons (or one of
her sisters) at Rickmansworth, send her into a siding, back on a steam
loco and couple up. The shunter had to go between the loco and the
coaches, despite the presence of the 4th rail. These days H&S would have
kittens.

Peter

I think that the issue is, if it does take more than 15 minutes - and it now
appears that this figure was quite bogus - but whatever it takes, it is
claimed to be due to the need for the train to re-boot and be acknowledged,
then the question is why do we make such over-complicated systems nowadays?

The same thing is true regarding 3rd-rail DC. *The over-complicated systems
cannot deal with momentary supply fluctuation such as occur during cold
weather. *This, combined with the foolish change to lightweight collector
sandals (you really can't dignify them with the word, shoes) has lead to
foolish condemnation of third-rail systems.

In both cases, over-complication is the underlying problem - and no-one in
DfT has the wit/guts to challenge this underlying, fundamental error - and
no-one in the industry dares to.

The light weight shoes are probably part of the reason NSR's EMUs fair
so badly in snowy conditions.

In the 1960s I can recall leaving Waterloo on a 4EPB during a light
sprinkling. Even today SWT's Siemens units make some progress. NSR
(an otherwise excellent railway) cancel services when their snow in
the forecast.

On Oct 26, 12:28*pm, 77002 wrote:
On Oct 26, 10:09*am, "Peter Able" stuck@home wrote:



"Peter Masson" wrote in message

...

"Jeremy Double" *wrote in message
...

Denis McMahon wrote:
On Thu, 25 Oct 2012 09:28:58 +0100, Peter Able wrote:

Dft: It takes over 15 minutes to attach a diesel locomotive.

I've never understood this. If the diesel loco is properly designed to
interwork with the unit(s) that it's expected to haul, then surely
(de)coupling should take no longer than splitting and combining any *MU
stock.

In the days of ETH-fitted Peaks on the Midland main line, they used to
reverse some trains at Nottingham in 5 minutes or so, and this included
uncoupling a loco at one end of the train and coupling another one on the
other end.

Time was when 2 minutes were allowed to detach Sarah Siddons (or one of
her sisters) at Rickmansworth, send her into a siding, back on a steam
loco and couple up. The shunter had to go between the loco and the
coaches, despite the presence of the 4th rail. These days H&S would have
kittens.

Peter

I think that the issue is, if it does take more than 15 minutes - and it now
appears that this figure was quite bogus - but whatever it takes, it is
claimed to be due to the need for the train to re-boot and be acknowledged,
then the question is why do we make such over-complicated systems nowadays?

The same thing is true regarding 3rd-rail DC. *The over-complicated systems
cannot deal with momentary supply fluctuation such as occur during cold
weather. *This, combined with the foolish change to lightweight collector
sandals (you really can't dignify them with the word, shoes) has lead to
foolish condemnation of third-rail systems.

In both cases, over-complication is the underlying problem - and no-one in
DfT has the wit/guts to challenge this underlying, fundamental error - and
no-one in the industry dares to.

Corrected version:

The light weight shoes are probably part of the reason NSR's EMUs fair
so badly in snowy conditions.

In the 1960s I can recall leaving Waterloo on a 4EPB during a light
sprinkling. *Even today SWT's Siemens units make some progress. *NSR
(an otherwise excellent railway) cancel services when there is snow in
the forecast.

"77002" wrote in message
...
On Oct 26, 12:28 pm, 77002 wrote:
On Oct 26, 10:09 am, "Peter Able" stuck@home wrote:



"Peter Masson" wrote in message

...

"Jeremy Double" wrote in message
...

Denis McMahon wrote:
On Thu, 25 Oct 2012 09:28:58 +0100, Peter Able wrote:

Dft: It takes over 15 minutes to attach a diesel locomotive.

I've never understood this. If the diesel loco is properly designed
to
interwork with the unit(s) that it's expected to haul, then surely
(de)coupling should take no longer than splitting and combining any
*MU
stock.

In the days of ETH-fitted Peaks on the Midland main line, they used to
reverse some trains at Nottingham in 5 minutes or so, and this
included
uncoupling a loco at one end of the train and coupling another one on
the
other end.

Time was when 2 minutes were allowed to detach Sarah Siddons (or one
of
her sisters) at Rickmansworth, send her into a siding, back on a steam
loco and couple up. The shunter had to go between the loco and the
coaches, despite the presence of the 4th rail. These days H&S would
have
kittens.

Peter

I think that the issue is, if it does take more than 15 minutes - and it
now
appears that this figure was quite bogus - but whatever it takes, it is
claimed to be due to the need for the train to re-boot and be
acknowledged,
then the question is why do we make such over-complicated systems
nowadays?

The same thing is true regarding 3rd-rail DC. The over-complicated
systems
cannot deal with momentary supply fluctuation such as occur during cold
weather. This, combined with the foolish change to lightweight collector
sandals (you really can't dignify them with the word, shoes) has lead to
foolish condemnation of third-rail systems.

In both cases, over-complication is the underlying problem - and no-one
in
DfT has the wit/guts to challenge this underlying, fundamental error -
and
no-one in the industry dares to.

Corrected version:

The light weight shoes are probably part of the reason NSR's EMUs fair
so badly in snowy conditions.

In the 1960s I can recall leaving Waterloo on a 4EPB during a light
sprinkling. Even today SWT's Siemens units make some progress. NSR
(an otherwise excellent railway) cancel services when there is snow in
the forecast.

Quite - and I can vouch for the even earlier 4SUBs, and even the pre-1920
3SUBs. There were pyrotechnics, but they got through. Nobody in the press
seems to be recognising technical over-complication as a really serious
issue, although I noted Tony Miles picking up on the issue of collector
sandals as a bad move in a recent Modern Railways - an issue first raised in
this group some time ago!

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

On the subject of 25 kV Met, Marylebone etc etc, I am still of the
view that a better Thameslink upgrade would not have been to link the
ex Midland lines to GN as KX/SP but to have linked the Midland to the
Met/GC at West Hampstead, with trains being able to both switch
between both routes. This could have been done using the sites to the
south of the present West Hampstead stations, and incorporated the NLL
station at a higher level.

This could have allowed the ML to retain its Moorgate link (but some
trains switching to the MET), allowed relief of Baker Street junction
(by having some MET trains switch to TL), and give and electrified
Chilterns route access to TL (solving the longer/more trains at
Marylebone issue).

It would also give a better spread of trains through the TL core - one
of the issues is GN realistically can't take more than 8 TPH off TL
but 24 TPH means 16 TPH have to head for the Midland which is not so
sensible. If those were (say) inner suburbans from (one time)
Wimbledon loop or other southern metro line those logically go to
Watford Met or Uxbridge, while some of the faster TL core trains can
go to [say] Aylesbury as well as Bedford.

Before some nitwit comments, it assumed that all surface lines and
Chilterns works will be to 12cars or 8car SDO where uneconomic - don't
say it is impossible - uk.railways said 4car NLL and 12car TL was
impossible but now are reality.

If this had been done with the TL works, you'd now have a 25 kV wired
Chilterns, and linking with other matters taking AC that way towards
Banbury (for Birmingham) would result in considerable synergy and
economy of scale with the current electric Spine project.

GN capacity in my view should be dealt with by new construction from
around Finsbury Park - thats where Crossrail 2 should go on the
north side.

--
Nick