Extensive train delays cause weekend chaos for Sydney commuters

New digital signalling systems were brought in across Sydney trains overnight to replace the 40-year-old analogue systems.

But the planned technology wasn't completed in time, leading to chaos for commuters. 

Thousands were left stranded across the city today, with pictures shared on social media showing people crowded onto stations and into the few trains that actually left. 

Services on the T1 North Shore, Northern and Western Lines, T7 to Olympic Park and the T2 innerwest line were all affected leaving disgruntled passengers reeling.

"It took us over an hour to get here. It was ridiculous," one commuter told 9NEWS as she finally hopped off at Central station. 

Siobhan Caulfield tweeted that it took her more than seven hours to get from Sydney to Newcastle, a trip which usually takes under three-hours. 

"We'd like to apologise to customers that were impacted as a result of extended trackwork from last nights signalling switch over," a spokesperson from Sydney Trains told 9News.

Greg Fogarty tweeted “You get better public transport in a third world country.”

One commuter said they waited up to 87 minutes for a train and another person on the northern line said their driver suggested catching a bus or walking over the Harbour bridge.

"We are providing a regular service on the T1 North Shore, Northern and Western Line to ensure customers are able to reach their destination. Buses are also supplementing services between Central and Strathfield stations," the spokesperson said.

Sydney Trains is confident services will have returned to normal for the morning commute.