Re: British accident track layout

["Notagunzel" <notagunzel@bigfoot.com>]

Geoff Lambert <G.Lambert@unsw.edu.au> wrote in message
7tjdg3$4tb$1@mirv.unsw.edu.au">news:7tjdg3$4tb$1@mirv.unsw.edu.au...

> Eddie Oliver <eoliver@efs.mq.edu.au> wrote:

> >The layout, as supplied to an international signalling mailing list by a
> >very reliable source, is complicated, but the RELEVANT parts of it are
> >thus:

(layout replanted & expanded for ease of explanation)

Track 1---------------------*--------------Down Main
                          B/
Track 2-----------------*-*----*------<H---Up Main
              |-OOO   A/      /D
Track 3----T>-------*-*---*--/
                    C\    E\
Track 4---------------*-----*------------

(note that irrelevant parts of the track layout aren't shown, & I've added another
crossover.)

> etc...

> I have a couple of questions.

I'll try to help.

> I still can't fathom how the Down train managed to cross the path of
> the Up.  Even if it passed the signals at points (normal)  "A" at
> danger

I have added to Eddie's drawing Signal SN109 like: |-000

As you say, the Crossover labeled A (actually numbered 8057) were beleived to be
normal, as were as the Crossovers labelled 'C'(8055), and 'E'(8059).

> and kept going to the points at "D", how could those points
> divert it across the Up Main unless they were set reverse.

The points labelled 'D' isn't a crossover, Track 3 just leads into a single ended
turnout on the Up Main.

> And, if
> they were set reverse, how could the Up Main be signalled for a
> movement?

They were beleived to be Normal.  The Thames DMU, labelled "T>", passed signal SN109
at stop.  The overlap distance between SN109 and the fouling point has been reported
as 300m+, well over the Standard UK overlap.

Because all the turnouts involved were normal, the HST correctly had a proceed
aspect.

> Am I missing something?

I hope I've explained it.

> One of the newspapers this morning
> suggests that the points in question were NOT (or should not have
> been) set for the crossover move and then says "but... the weight of
> the Thames train pushed it through the points and into the path of the
> express."

The press has no idea & is just confuesed.  A good trawl through uk.railway gives you
a much better idea of what happened.  Todays Hun reports that the driver of the DMU
"went through a red spot signal and then ignored two yellow warning lights".  This as
anyone who knows anything about railways, means absolutely nothing.

> What can this mean, if "D" was also set normal?

Turnout 'D' could have been trailed, depending on how far the DMU got.

--
Mr Notagunzel.
Rail Transportation Connoisseur.
notagunzel@bigfoot.com
(Waiting for the next move at http://www.bigfoot.com/~notagunzel)