There are only three major railway crossings in Barcaldine. The others are mostly for access to local properties. They all have crossing numbers given to them.
If something happens at a railway crossing, there is a sign which tells you which phone number to call, and which crossing number to quote.
So to find the coordinates for this cache, you need to look at the sign near the Waypoint called "Rail Crossing ' Start Here". You can see this sign from either side of the rail corridor, but although there are only less than ten trains a week that go through here, play it safe and cross over the rail line on to Waterloo Road (the dirt track as we call it), and you can easily see the sign from there.
S23 33.ABC E145 21.XYZ where
A is the first digit of the crossing number
B is the sixth digit of the phone number
C is the seventh digit of the phone number
X is the second last digit of the phone number
Y is the third digit of the crossing number
Z is the first digit of the phone number