Adults who were physically and sexually assaulted as children at the notorious Fairbridge Farm School in central western NSW have been awarded $24 million in the largest compensation payment for survivors of institutional child abuse in Australian legal history.

More than 150 former child migrants brought the class action against the federal and state governments and the Fairbridge Foundation, which ran the scheme promising a better life overseas for underprivileged British children.

Instead, the children suffered abuse which their class action lawyer, Slater and Gordon's Roop Sandhu, described as "sickening and terrifying".

"This is a historic moment for victims of institutional abuse," he said.

Former Fairbridge Farm resident David Hillexpressed relief that the settlement would save abuse survivors the trauma of a trial but criticised the defendants for dragging out legal action at an estimated cost of $10 million to the taxpayer.

"This is a terrific acknowledgement after decades of denial and resistance from the Fairbridge Foundation, from the State Government and from the Federal Government, of the great wrongs which were done to so many of these kids," he said.

"It's outrageous that it has been bogged down by the defendants in the Supreme Court for years. Eight of our friends have died in the process, waiting for justice."

An estimated 130,000 children were taken from the UK and sent to Australia, New Zealand, Canada and Zimbabwe as part of the British child migration scheme.

More than 1200 were sent to the Fairbridge Farm School in Molong, which operated from 1938 to 1974.

"They were as young as four, they were shipped to the other side of the world, some were wrongly told they were orphans," Mr Hill said. "They had a completely loveless childhood."

The former ABC boss and Ian "Smiley" Bayliff, his childhood friend from Fairbridge, have been long time advocates for justice for the children who were abused at the school. Mr Bayliff arrived at Fairbridge from Manchester when he was eight, enduring floggings with a riding crop and long hours of hard labour.

Former resident Lynda Craig, whose nose was broken in a beating at the school, said Monday's settlement was an acknowledgement of past wrongs but would not bring her childhood back.

"This result won't take the demons away from us but it will certainly make Fairbridge, the Commonwealth and the State accountable for their actions," she said.

"This is justice for the children at Fairbridge who were exposed to sexual predators, exposed to physical and mental abuse at the hands of unskilled workers and were sent out in the wide world with no social skills. The time taken to resolve this case has taken its toll on those involved, including myself."

Ron Simpson, one of the first children to arrive at Fairbridge Farm School when it opened in 1938, spent three years in hospital after having his back broken in a beating by the principal.

"It has been a burden all my life," he said. "These kids, they went through hell. I don't have good memories of the place."