I don’t believe that I’ve never noticed this sign before, tucked away on the top (eastern end) corner of the rail bridge over the Styx. How many times have I walked under it?
Another question: Islington is 164.475 km from where? Can’t be Central, that’d be less. And why so precise? Answers please!
Hamilton North, NSW 2292 
It is the rail line distance from Central :-).
The Main North Railway is very very very curvy and takes an indirect route to Central hence the larger number than expected.
That point is only down to the nearest metre, so not exceedingly accurate but rail workers need it to get a bit of an idea for setting out rail works. They would have a big drawing showing all of the signals, bridges, transfers, electrics etc and it’s corresponding distance from Central so it makes it easier to find stuff.
Ah! Thank you, Rationalist.
So is that plaque the actual measuring point, or just the bridge in general? If so, is the distance to the end of the bridge or the start of the bridge? Or the middle?
Who would have thought that this would be so interesting!
Is that plaque the actual measuring point? Yes I would think so.. it would be one of the many measuring points used as a reference for rail works. But since it’s in a bit of an odd location it may not be used very often.
The actual 164.475 km mark is probably the centreline of the sign, but given that would be down to the nearest metre, it is probably only a roundabout measure.
It’s quite a neat looking sign, it must have a purpose since it was only done in 2003. Unusual to be in such an odd spot though.
Love the blog by the way, I never knew about the gasworks or the old lightbulb factory until now, or even much about Styx Creek. There is so much history of this area that I haven’t uncovered.