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

["BJ" <macgunzal@bigpond.com>]

Mark is correct regarding the suggestion that what you saw were sidings.
Devices such as slips, derails and scotch blocks are primarily designed to
prevent runaway vehicles departing a siding and heading for the mainline
after brake failure or similar. You may notice that the derailing device is
always on the side furthest from the main line where possible to prevent a
collision of a derailed runaway with a scheduled train.

Installation of these devices on crossing loops (which are classified as
mainlines) really adds as many problems as it solves, (e.g. detection of
slips being closed, etc.) especially as they are really meant for slow
moving vehicles - not really applicable to situations like Violet Town etc.

Regards, BJ