AN ADANI protester who claimed he was acting as 'police liaison' when he stopped a coal train was given a $200 fine in Bowen Magistrates Court yesterday.

Edward John Mortimer appeared on his own behalf and pleaded guilty to trespass on a railway after the 25-year-old took part in a political protest against the Adani Carmichael mine which stopped an Aurizon coal train.

The court heard the Dulwich Hill man acted as 'police liaison' for two other alleged offenders who climbed aboard the Aurizon train with an "anti-coal banner" on a section of line near Buckley Rd at around 6am on January 2.

Police prosecutor Hannah Beard said Aurizon estimated more than $10,000 was lost due to the incident which was also said to detain Bowen's emergency services including police and QFES from the community's needs.

The court heard while Mortimer did not set foot on the train himself, he was photographed by an Aurizon employee as being on the rail corridor after the train had stopped.

Mortimer said it was a momentary lapse in judgment which saw him step into the rail corridor and he intended to act as a neutral liaison between police and protesters without breaking the law.

The currently unemployed industrial designer by trade cited a conviction would affect his future job prospects and travel plans.

"I haven't had paid work in 12 months and am currently living off my savings and not receiving any support from the government which does leave me in a precarious financial situation," he told the court.

Magistrate Ron Muirhead cited his co-operation with police, early plea of guilty and "person of good character" as factors in a reduction of penalty.

Mortimer was fined $200 to be referred to SPER with no conviction recorded.