On 2008-11-07 11:37:19 +0000, disgoftunwells said:

On 20 Oct, 11:30, D7666 wrote:
On Oct 20, 12:11 pm, Roland Perry wrote:



In message
, at
04:06:19 on Mon, 20 Oct 2008, D7666 remarked:

I won't believe it's finished until I
can get a through train from Cambridge to Gatwick - one of the origi
nal

I am now of the opinion you won't.

Even though they completed the tunnelling into SPILL I have alwys been
sceptical about connecting up GN to it.

They are going to all this trouble of re-arranging appoaches to
Blackfriars and south/east thereof to avoid as far as possible
conflicting moves to make 24 TPH in the core work, and then build a
new junction across which every move will conflict right *in* the
core ?!?!?!?

Is it a flat junction? I thought the northbound line tunnelled under.

--
Roland Perry

Each switch forms a flat junction on both roads - even if there is no
crossing by tunnelling.

When running 24 TPH you don't really want any points at all.

Don't forget these are long 12 car trains running into or out of the
SPILL station stop - and all trains will stop - they ain't going to be
high speed across the convergence point.

Take the Jubilee line now (before resgignalling). That is planned 24
TPH in the peaks, with trains half that length, and it barely works.
Now put in a new junction at say London Bridge, right off the end of
platforms of one of the busiest core stations, even with a dive/fly to
avoid a crossing, but nonetheless convergence points on both west and
eastbound roads. *You reckon 24 TPH would still work ?

It works with the Munich S-Bahn. However, they do have double sided
platforms.

At the risk of being pedantic the S-Bahn in Munich schedules 30 trains
per hour during the peaks (admittedly not at the moment as there have
been problems with the brakes/wheel slide protection during the autumn
and the automatic door closing equipment, but these should be cleared
up by the beginning of next year).
Only the 3 busiest stations of the 5 in the tunnel section have the
double sided arrangement (the Hauptbahnhof, Karlsplatz/Stachus and
Marienplatz), but the Ostbahhof has 4 platforms dedicated to the S-Bahn
service so the trains can be launched into the tunnel section. Note
that two lines, currently the S5 and S6, /reverse/ at the Ostbahnhof.

At Donnersbergerbrücke, west of the Hbf, routes from the south and from
the west come together on each side of an island platform; they join
just east of the station for the run towards the city centre via the
Hbf. The signalling is such that about 75 seconds after a train has
left one platform the one on the opposite face can also leave. These
trains are quick - the Baureihe 423 is an articulated unit with 4 body
sections carried on 5 bogies, 4 of which are powered. It has an empty
mass of 105 tonnes with an hourly rating of 2400kW which gives a
power-to-weight ratio somewhat better than that of a Deltic running
light! They also have /lots/ of doors - each body section has 3 pairs
of swing-plug doors so half the side of the train opens.

Trying to run a 24tph service with only 2 doors per side in a longer
coach body, single sided platforms and a lower power-to-weight ratio
seems to me to be hard way to earn a living.


One of the problems with the Jubilee is some stations are quite quick
(Waterloo East) and others are slow because of passenger volumes
(Canary Wharf, LB, Waterloo).

How will the spread be on Thameslink?


--
Nick

--
Nick


--
Robert