Five Brisbane train lines are experiencing delays  after a signal fault this morning. 

Beenleigh and Gold Coast trains are worst affected, with delays of up to 40 minutes inbound. 

Meanwhile, Airport, Doomben and Ferny Grove trains are also experience delays of 15 minutes during peak hour. 

The opposite is occuring when heading outbound – Beenleigh and Gold Coast delayed 15 mins, Airport, Ferny Grove and Doomben delayed 40 minutes. 

The original fault occurred at Woodridge station.