Environmental activists have launched an assault on NSW railways.

Protestors angry at the use of fossil fuels chained themselves to tracks to stop coal trains from reaching the Port of Newcastle.

Images showing a man chained to the rail line were hailed by supporters including Greens Senator for NSW, Lee Rhiannion.

The 27-year-old man held up part of the NSW coal industry for several hours near Kooragang Island before police were forced to cut him free.

But his liberation was short-lived, as police arrested the man immediately after.

Similarly, about ten were arrested from a reported 150 protestors blocking work at Maules Creek, Werrris Creek, Tarrawonga and Rocglen coal mines.

Mine operator Whitehaven is downplaying the potential drop in productivity.

“There have been a number of protests this morning but the suggestion that they have ‘shut down’ all our operational and development sites is false and consistent with grandiose claims made about the impact of protests generally,” a company spokesperson said.