Today's commuter fun for Sydney!

CityRail advises that trains are being delayed on the Eastern Suburbs & Illawarra Line in both directions due to a private freight train with mechanical problems at Jannali. Major delays can be expected. Numerous bus companies have been contacted, however due to their own commitments only a limited number of buses are available to supplement late running train services between Waterfall and Sutherland. Train services from the City to the South Coast Line will also experience delays. CityRail apologises to customers who are experiencing lengthy delays due to this incident.

Wait, so suburban trains share lines with freight? Showing my complete ignorance of state rail here, but is that normal?