>mauried@commslab.gov.au (Maurie Daly) wrote:
>>
>>
>>LLTC is still in operation between Wodonga A & Albury South on both SG & BG
>>lines.
>>I suspect that this section as well as the Camberwell - Riversdale sections
>>are now the only ones left , possibly in the whole country .
>LLTC as such was only ever a Victorian system. However the NSW equivalent
>of Single Line Track Block is still well and truly alive. There are plenty of
>SLTB sections (e.g. Quakers Hill -Riverstone, Mulgrave - Richmond,
> Caringbah - Cronulla), and also SLTC sections which
>become SLTB when the normally-remote end is switched
> into local control (e.g. Blacktown - Quakers Hill, Sutherland
>- Gymea, Unanderra - Dapto).
>The prime difference in Victoria between ATC and LLTC seems to be that the
>starting signals in an ATC section can be cleared just by the signaller at one
>end reversing the starting signal lever (provided of course that the section
>is clear), whereas LLTC requires action from the signaller at the other end as
>well (i.e. the NSW accepting lever principle in SLTB).
>Are you sure that Camberwell - Riversdale was not altered to ATC at the same
>time that Camberwell was modified from (effectively) LLTC to ATC on the main
>line bidrectional centre track?
>Eddie Oliver
LLTC or an equivalent of it also existed in the days of the old SAR on the
single line from Belair to Nairne. (it was removed when Belair to Tailem Bend
was converted to CTC.)
It was not exactly the same as the Vic version as there
were 4 levers involved,2 in each of the cooperating signal boxes.
One lever controlled the operation of the home signal controlling the entrance
into the single line section ,and the other lever locked or unlocked the
opposing ends signal control lever.
Once a train entered the single line section all levers were locked in the
frame of both boxes until the train exited the single line section.
The main differance was that in order to clear either ends home departure both
signalmen had to cooperate.
I dont know what the SAR called the system.
cheers
MD