The Hunter's coal network was disrupted this morning following a protest at Sandgate.
Anti-coal activist Sarah Barron blocked the rail line preventing trains from reaching Newcastle Port for about three hours.
She was arrested along with two people who filmed the protest.
They're currently being questioned by police.
Ms Barron said the protest was about sending a message.
“Australia exports more coal than any other country, this makes us one of worst contributors to climate change. Setting domestic emissions targets — something our governments have so far failed to do — is not enough," she said.
"Mining and exporting coal in the face of what is an already spiralling climatic crisis is to condemn my generation and those to follow."