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 original

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 ?

Camden Town and Kennington are similar problematic locations on the
Northern - thats why they want to split the servcie and avoid
convergences.

--
Nick


--
Nick