Auckland commuters are likely to face delays again tomorrow morning as Britomart is expected to remain closed overnight and through the morning after a train derailed near the platform this morning.

And there was no indication of when the station would be open again.

The delays crippled the busy station after three of six carriages derailed as a train left the station at 9.45am. Some passengers described the accident as a sudden shake "like an earthquake".

The six-carriage train had 33 people on board but no one was injured.

This afternoon,commuters told the Herald the closure had added as much as an hour to their trip home.

Louise Caro was aware of the closure of the station before arriving but was annoyed at the confusing planner provided by Auckland Transport detailing what bus she needed to catch.

She was on her way home from work to Morningside and expected the interim transport options would mean her commute was at least an hour longer.

 "I would normally be home by 5.10pm but God knows how long it will take me now. I may have to get my husband to come get me.

"It should be fixed by tomorrow, it is just one train for God's sake. I'm frustrated."

She was lucky she lived in central Auckland and feared for the length of commute for people in the fringes of the city.

About 12 Auckland Transport staffers were at the two entrances directing people to the Newmarket and The Strand stations via buses.

Andrew Blomfield was travelling home to Papakura and said the closure was " bit of a pain in the arse".

Praveen Sivapalan said he didn't know much longer it would take for him to get home to Howick but expected it would add another half an hour at best.

At worst it could be more than an hour, he said.

An Auckland Transport spokesman said there would be delays and changes to where the trains departed and arrived this evening and through to the morning.

The station would be closed overnight as the Transport Accident Investigation Commission looked into the incident.

The commission arrived at the scene about 3pm and was now in control of the station, Auckland Transport media relations manager Mark Hannan said.

Transport Accident Investigation Commission senior communications adviser Simon Pleasants said investigators would be mapping, recording and gathering evidence from the site to make sure the re-railing crew had all the information they needed to get the train back on track.

He could not say if the train had been put back on the rail or when the station was likely to open.

UPDATE: From 9pm tonight Eastern Line services will only operate between Manukau and Panmure. No train services will operate from Panmure to the Strand after this time. There are no services to or from Parnell Station until further notice. https://t.co/kvCH4Pke1c

— Auckland Transport (@AklTransport) May 9, 2018

"The commission opens an inquiry when it believes the circumstances of an accident or incident have - or are likely to have - significant implications for transport safety, or when the inquiry may allow the commission to make findings or recommendations to improve transport safety."

Pleasants said at 7pm commission investigators had completed their evidence gathering and had handed back control of the site to KiwiRail and Auckland Transport.

Eastern Line services will arrive at and depart from The Strand on a 20-minute frequency, Western and Southern Line services will arrive at and depart from Newmarket on a 20-minute frequency.

Onehunga Line services will run as a shuttle between Onehunga and Penrose, linking to Southern Line services.

Auckland Transport advised after 9pm the Eastern line services would only operate between Manukau and Panmure.

"No train services will operate from Panmure to the Strand after this time.

"There are no services to or from Parnell Station until further notice."