Brisbane River commuters could be in for a free ride as CityCat and ferry staff prepare for protected industrial action.

Maritime Union of Australia deputy Queensland branch secretary Jason Miners said members planned to turn off ticketing machines as part of proposed industrial action.

CityCat crews are preparing for industrial action after EBA negotiations broke down. Credit:Robert Rough

He said the union had engaged the Electoral Commission of Queensland to run a ballot of members.

Mr Miners said MUA members had been in negotiation with Transdev, the private operator of the Brisbane City Council-run service, for more than 18 months.