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. 

UPDATE: Beenleigh, Gold Coast, Airport, Ferny Grove & Doomben line delays up to 40 mins. Click here for more details: https://t.co/zVjwuLTaQt #TLAlert #TLBeenleighline #TLGoldcoastline #TLAirportline #TLFernygroveline #TLDoombenline pic.twitter.com/iMFrqpMevg

— TransLink (@TransLinkSEQ) October 15, 2018

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.