View Single Post
  #24   Report Post  
Old November 28th 05, 10:30 AM posted to uk.transport.london
Clive D. W. Feather Clive D. W. Feather is offline
external usenet poster
 
First recorded activity at LondonBanter: Jul 2003
Posts: 856
Default Victoria Line on Wednesday morning

In article , I wrote:
Seven Sisters: you can only do south-to-north from platform 4. Either:


Checking an old rulebook, I have some amendments to make:

* no route indicator at VL6, forward to VL7, change ends, signal VL20
takes you over the scissors to VL19 which protects the entrance to
the southbound platform.
* right-hand indicator at VL6, forward over the crossover to a fixed red
light behind VL22A, change ends, signals VL22A and VL22B take you
straight to VL19.


This is correct, except that the fixed red is placed so that VL22A will
be mid-train and can be ignored.

North-to-south is harder but possible: into platform 5, change ends,
signal VL8 takes you on to the depot exit road, over the scissors, and
up to VL7.


This is wrong. VL8 doesn't have a junction indicator, but nevertheless
can clear for two routes: either to VL7 on the depot entry road (62
road) or to the fixed red on the depot exit road (63 road). VL22B also
doesn't have an indicator but can clear for routes to either platform 4
(northbound) or 5 (southbound). So the north-to-south reversal is done
by: into platform 5, change ends, VL8 takes you to the fixed red on 63
road, change ends, VL22B takes you over the crossover and into platform
4, change ends, depart normally (VL6 with left-hand indicator).

[*] VL20 is not shown as having a junction indicator. I'm assuming,
therefore, that the only route from it leads to VL19.


This is correct.

--
Clive D.W. Feather | Home:
Tel: +44 20 8495 6138 (work) | Web: http://www.davros.org
Fax: +44 870 051 9937 | Work:
Please reply to the Reply-To address, which is: