I hesitate to propose a signalling instruction as a pointless sign, but at first glance this makes a good candidate.
Does this mean that EMUs can SPAD with immunity?
Maybe not ...
Knowing the location, I think I know what it is all about, but others may care to hazard a guess.
UPDATE: This from Bruce...
G'Day FC,
Is it because the next signal after CL11 is in tunnel, and the sensitive Queenslanders do not want to be barbequed by fumes from antiquities that burn their own fossil fuel on board?
Or get their nice OLE knitting coated with carbon deposits when said antiquity stands at danger?
If CL11 is green, the theatrical traction has the road all the way to the open air section.
Right Away Cobber!!
UPDATE: This from our International Correspondent...
Curiously, Queensland Rail, like Dick Fearn's IE, is taking the financial hit of training more steam men to safely - and sustainably - operate kettles.
How quaint of former dominions to unbelt for this - have they not heard of Wet Coat's money saving business model of bunging retired (or in some cases, rest day) DBS men £120 for a driving turn?
Cheap and dirty, like their XXXX (removed on legal advice. Ed).