c40 years I worked in a unionised factory for one day.
The company I worked for sent some defective parts to the factory, which had a production line and needed the parts rectified PDQ.
Only a simple repair. Bright and early the next day we turned up at the factory gate in a crewcab loaded with tools and parts.
We never got through the gate.
The union had learnt that non union members would be working in the factory and threatened to strike.
The union officers had a "solution" for the management, union staff would rectify the parts, at a special "negotiated" overtime rate.
My employer would then receive a large, unwelcome, invoice.
This "solution" was imaginary, the fault was in some special components, which the factory could not provide.
Eventually the factory management informed us that our employer wanted us to return to base, no mobile phones then.
Bright and early the following day we turned up again at the factory gate. We were told that we would not be welcomed by the union members.
An area had been reserved for the rectification work, which we were not to leave unless it was to visit the lavatory, in which case all four of us were to go together.
Our presence was totally ignored by the comrades. Job done and signed off by the management, we packed the equipment back in the pickup and drove away.
At least we would have done if all its tyres had not been slashed!