A federal judge has lashed the Construction, Forestry, Maritime, Mining and Energy Union for using "bogus" safety claims to shut down three Sydney construction sites as he handed the union and two officials a combined $156,900 penalty.

Federal Circuit Court judge Robert Cameron said the "deliberate", "flagrant" and "serious" contraventions of workplace laws were "at their heart, a form of extortion".

The judge said the CFMMEU was "a notorious recidivistic contravener of industrial legislation". Credit:Joe Armao

The court in August found CFMMEU officials Tony Sloane and Luke Collier's shutdown of crane operator Reds Global's Ultimo, Erskineville and Hornsby work sites in 2014 citing safety concerns was contrived as a way to "inconvenience" the company in retaliation for its handling of a worker who had injured his knee.

Mr Sloane was found to have engaged in adverse action, coercion ­and organised unlawful industrial ­action while Mr Collier was found to have ­engaged in ­adverse action and coercion.