When Wollongong resident Chris Cartledge saw the Mercury's story last week about "green coke" technology for steelmaking, he thought it was a case of back to the future.

Mr Cartledge remembered well how his family used to make charcoal for use in the Port Kembla steelworks, mid-last century.

He told the Mercury how the homemade charcoal operation - based on hard work and making the most of every opportunity - was the doing of his tough and entrepreneurial grandmother, Johanna Van Dragt.

Last week's story told of an innovative New Zealand company, CarbonScape, which plans to use microwave energy to concentrate the carbon from timber industry waste material into a substance they are calling green coke.

It would be able to provide the carbon content for steelmaking, without the heavy pollution that is a byproduct of coke ovens, where coal is heated above 1000 degrees Celsius to concentrate the carbon.

BlueScope in Port Kembla is keeping a "watching brief" on the development, and its subsidiary New Zealand Steel has inked a supply agreement with CarbonScape for 9000 tonnes of the material provided it is commercially useful.

In recent years the CSIRO has estimated between 32 and 58 per cent of coal and coke in steelmaking could be replaced with charcoal, with significant reductions in greenhouse gas emissions.

The use of charcoal in steelmaking is not new - it is used in some countries today - but the microwave energy method is somewhat different to the way the Van Dragt family made their charcoal.

Chris Cartledge's uncle, Christaan Van Dragt, provided most of the muscle for the enterprise, felling and collecting trees from forests between Picton, Bargo and Yerrinbool.

After cutting the logs to lengths he could single-handedly load onto his Ford, he trucked the logs to Tahmoor, where the family owned land next to the highway.

The logs were then burnt in a controlled-oxygen environment, in four pits about three metres wide and long, and 2.5 metres high. One of the pictures here shows a young Chris, aged 10 at the time, with his brother David, 9, in one of these pits.

The boys didn't have to work in the charcoal pit, as perhaps evidenced by the fact their clothes are still white.

The pits had to be covered in order to control the flow of oxygen, essential in making charcoal. So sheets of corrugated iron were used, covered with wet hessian bags.

This wasn't the first enterprise Johanna Van Dragt set up, following the death of her husband in 1946 in a motorbike crash while working on the Cataract Dam.

"She was a great character," Chris said.

"She was a wonderful lady and very entrepreneurial."

The children had a nickname for her, based on the rhyme with Johanna.

"Behind her back it was Goanna - but she could run faster than any of us, so you never said it to her face," Chris said.

"She was a strong woman. She was the head of the family for a long time."

Leonardus Van Dragt and Johanna Klooster, who would become Chris's grandparents, had moved from Holland to the United States in the early 20th century, with their respective families. They met and married in Boston in 1914.

Several years later, however, Leonardus moved to Australia, following his brother who had emigrated some years earlier and had found success.

Johanna was left behind in Manchester, New Hampshire, with three children and little money.

But she had her wits, and knew how to make gin. She set up a still and sold bootleg liquor during Prohibition, saving as much money as she could.

"She carried the three kids across America and then across the Pacific to Australia, where her husband was waiting for her," Chris said.

"She raised the money, and did all that on her own."

The family settled in Douglas Park, but later bought the land at Tahmoor.

"It was tough work," Chris said.

The work was hard and the living wasn't easy either. But the family used what they had to make a coin.

"She had this land, and had to do something with it.

"They sold what they could. They grew vegies and sold them on the side of the road."

Johanna saw the potential to cash in on the weekend drivers taking a trip from Sydney. She set up a picnic ground by the highway, charging for hot water and the use of the shade structures they built from timber and flattened 44-gallon drums.

Nearby she started the charcoal pits.

Christaan would get the fire going with some kindling, and let it burn for several days. The result was logs of charcoal — concentrated carbon.

When it cooled, casual workers would help load the charcoal into large sacks for transport to Port Kembla.

"They'd just jump in and bag it. It was a filthy job," Chris said.

It was enough to keep the family out of poverty and on the road to success.

"That was the main income for the family," Chris said.

"The Dutch are very good with money.

"They had a car, they were comfortable. They were good with their money, they did all right in the end."

He was amused to see the innovators at CarbonScape working on a new way of making charcoal using modern technology.

"They've invented something with microwaves ... but they were controlled-burning green timber for steelworks carbon back in the '40s and still in the early '50s," Chris said.

"It's like back to the future."