Re: [General] Information about block working

[Eddie Oliver <eoliver@efs.mq.edu.au>]

"f.u.i.t.b.e.t" wrote:
> 
> The type of block working you are referring to occurs at many places  what
> about Cootamundra nth to Cootamundra West. You come off Double line track
> block and automatic and on to Double line block which is different to block
> telegraph tyers single or three wired.With double lined block each box has
> an accepting lever and it does exactly that it accepts the request for
> signal clearance so unless the bloke at coota west pulls off the accepting
> lever the bloke at Coota nth cannot clear the signal to go around the corner
> to Coota west and the same occurs on the up.

No, that is NOT the type of block working we are talking about. You are
seeking to distinguish between Double Line Automatic (DLA) and Double
Line Track Block (DLTB), and the terminology is further confused by the
unfortunate generic use of "Track Block and Automatic" (TBA) which no
doubt has caused much confusion over the years. All of these involve
track circuits and accepting signals. However this discussion was about
neither of these systems, but rather block telegraph working (whether
with Tyers or standard block instruments) without either track circuits
(except within interlockings) nor accepting levers.