In article
-september.
org, (Recliner) wrote:

e27002 wrote:
On Monday, August 3, 2015 at 10:10:00 PM UTC+1, Mizter T wrote:
On 03/08/2015 13:55, Paul Corfield wrote:
After many months of negotiation with sole bdder Thales TfL have
confirmed that they have placed a contract worth £760m for the SSR
resignalling. A small (ahem!) cost increase from the £345m Bombardier
contract that was scrapped 18 months ago.


http://www.railwaygazette.com/news/n...w/thales-award
ed-london-underground-sub-surface-lines-resignalling-contract.html

Unfortunately we have to wait until the early 2020s for it to complete
and only then can meaningful work take place on subsequent upgrades to
the Picc and Bakerloo lines.


At last! I know that neither side wants to muck it up this time, but I
was starting to wonder whether the allowable annual Biro wastage was
being negotiated.

Perhaps this time the supplier can consider the needs of the sections
where track is shared with national rail services. Last time the
expectation that Chiltern should adapt their rolling stock to TfL's
needs was somewhat over reaching.

Thales could do worse than look at the signalling planned for the
Thameslink Core. Anything that can copy with Thameslink's frequency,
and complexity, could surely work for the Circle Line and her SSR
cousins.

What? You must be joking! The Thameslink core is trivial compared to the
LU subsurface lines.

The Circle line has two busy flat junctions and two busy triangles. The
Met has termini at Baker St and Aldgate in the East, and Uxbridge,
Amersham, Chesham and Watford in the West. It shares tracks with the
Piccadilly and Chiltern lines, and has both fast and semi-fast services.
Similarly, the District has four western termini, as well as sharing
tracks with the Piccadilly and Overground. It has several destinations in
the central area so trains can be turned back at many locations.

There are very few parts of the SSL network where all the trains in both
directions share destinations. Some parts have high density urban services
where successive trains every two minutes might be headed to five
different branches, while others have fast services.

Running all that with a fully automated system is truly complex, much more
so than the short, relatively simple Thameslink core.

And the Thameslink core is only planned to handle 24 trains an hour. SSL is
going to handle over 30.

--
Colin Rosenstiel