As hundreds of coal train drivers walk off the job, the State's mining industry is warning the strike could damage the Hunter Valley's reputation overseas.

Pacific Coal trains across New South Wales have come to a halt this afternoon.

800 coal rail workers have commenced industrial action that is expected to last 48 hours.

It is over failed pay negotiations between Pacific National and the Rail Tram and Bus Union and is likely to stop the movement of up to 600,000 tonnes of coal.

The Minerals Council of New South Wales is warning the strike could have detrimental impacts for the Hunter Valley's economy.

CEO Stephen Galilee is hoping the dispute will be resolved as quickly as possible.

"To protect the reputation of the Hunter Valley coal supply chain, here in Australia but also overseas as well," he said.

"A disruption to the coal supply chain itself through delays and disruptions to coal deliveries through the port, are going to have an impact on our reputation as a reliable supplier overseas."

The delayed coal is estimated to be worth $50 million.

Train driver "Tony" says it is all about getting a fair wage from Pacific National.

"We do a fair day's work, we'd like a fair day's pay for it.

"You know, everyone seems to think that we're being unreasonable, but we're not.

"We're only asking for something that we deserve.

"What they're offering us isn't fair.

"Everything is going up; petrol is going up and everything.

"You're trying to make it so that you can provide for your family."