Re: Catchpoints - what are they?

[Ben <sporologist@yahoo.com>]

Both of these appeared fine for me, using netscape communicator 4.5

signal_spotter@my-deja.com wrote:
> 
> Duh!! here we go again. If you cut and paste the diagram into Notepad
> and then place the curser after (OL1 via P10N) and hit return, then put
> the curser after OL1/4 and hit return, you should get a fair
> representation of the diagram. Meanwhile I'm going back to school to
> brush up on ascii drawings :-)
> 
> regards Ian
> 
> In article <8hf0fl$33c$1@nnrp1.deja.com>,
>   signal_spotter@my-deja.com wrote:
> > Joseph,
> >
> > It seems my previous attempt at drawing ascii representation of
> railway
> > lines didn't quite work. Hopefully this attempt will.
> >
> > Loop lines are the adjacent line to the main line. I'll try to explain
> > it with a diagram.
> >
> >   -0-0 S1  loop line         S2 -0-0  / catchpoint P10A (OL1 via P10N)
> > --+--------------0---------------+---/
> >         T1       OL6      T2          \
> >                  via P10R              \
> >                                         \
> >   -0-0 S4  main line    T4   S3 -0-0     \ points P10B  T6  OL1/4
> > --+--------------0---------------+--------------+-----------0--
> >         T3       OL6 via P10N        T5   S5 0-0-      S6 0-0-
> >
> > So hopefully the diagram worked out. Anyway the legend is as follows:
> >
> > -0-0   = signal, S1 denotes lever 1 etc
> > --+--  = track with blockjoint
> > --0--  = track with blockjoint that's an overlap point ie OL6 is the
> > overlap extremity for S6 and OL1/4 is the overlap point for S4 and for
> > S1 if P10 are reverse. OL1 is the overlap point for S1 if P10 are
> > normal.
> > T1     = track circuit name. A track circuit is an electrical circuit
> > that detects the presence of a train. The blockjoints are the
> > extremities of each track circuit.
> > P10A   = the catchpoints operated by lever 10 (A end ie closest end to
> > Sydney)
> > P10B   = points also operated by lever 10 (B end ie furthest from
> > Sydney)
> >
> > So the operation is as follows. With P10 Normal ie catchpoints open,
> > points normal, you can signal a train from S1 (loop line) and S4
> > (mainline) simultaneously as both signals have valid overlaps. S1
> > detects T1, T2, T5 and (T6 when P10 reverse). So with P10 normal it
> > doesn't look at T6. S4 detects T3, T4, T5, T6 and P10 normal.
> >
> > S6 detects T6, T5, (T4 when P10 normal), (T2 when P10 reverse).
> >
> > P10 points are called 'facing' for moves from S1, S2, S5 and S6
> > and 'trailing' for moves from S3 and S4.
> >
> > Anyway I hope this helps explain it a bit better.
> >
> > regards Ian
> > Signal Design Engineer
> >
> > Sent via Deja.com http://www.deja.com/
> > Before you buy.
> >
> 
> Sent via Deja.com http://www.deja.com/
> Before you buy.