If you happen to be within the Sydney Metropolitan area you can view the traffic on Sydney Trains lines here:
I don't really trust it 100% though and it won't show anything on ARTC lines either... Look for the gray question marks. It doesn't give any loco info but will give run number and sometimes origin/destination.
The data comes from TfNSW Open Data
, so it isn't really intended for tracking non-pax services. Currently, the operator, origin and destination information for non-pax services are decoded from the run number.
The only ARTC/4Trak data available is for NSW TrainLink regional train and coach services. All other services are filtered out by NSW Trains.