Re: Crossing loop design (r.e. Southern Aurora crash)

[Notagunzel <notagunzel@bigfoot.com>]

Christopher_Martin GORDON wrote:
 
> Autos are numberd like above letter(s) and number, odd is up and even
> down.  In newer numbering autos have the station code and a number,
> if the number's first digit is even, like 0,2,4,6,8 then it is just
> an auto, but if the first digit is odd 1,3,5,7,9 then the auto is
> controled, like for level crossings. and if the last digit is odd then
> down and if even then up (different to old style numbering)

Metrol style numbers appear when the auto is in or immediately near an
interlocking.

'Plain line' autos still retain X123 style numbering viz. Upfield.
 
> Homes have lights in a vertical line and never have a marker light,
> usually fitted with a third light to show, red over red over yellow
> homes are numbered by the lever number ie 65 or the new system with
> the station code and three digits always starting with 1,3,5,7,9
> some homes are fitted with an 'A' light and when red over red and 'A'
> is displaied then it can be treated as an automatic signal.
>
> For new numbering:
> first digit is
> 0 or 1, Clifton Hill group
> 2 or 3, Burnley Group
> 4 or 5, North Melbourne Group
> 6 or 7, Caufield Gorup
> 8 or 9, Special (incuding Sandringham)

Newport and Sunshine used 6/7
 
> Numbering at Flinders Street and city loop is the same as this
> expect that there is no station code.

Up end of Nth Melbourne has the intuitive prefix IAA (Inner Area A?) 
 
> P.S. I got it wrong above
> OLD SYSTEM: odd is down, even is up
> NEW SYSTEM: even is down, odd is up

Its messier than this, west of FSS use the Old/proper convention
Odd/Down, Even/Up

The entire Metrol signal numbering scheme appears like a good idea, but
the swap in Odd/Down, Odd/Up depending on what side of FSS you are is
ill-conceived.

BC