How builder Manuel Hornibrook turned Sydney Opera House dream ...

The story of how the Sydney Opera House was constructed goes back to the "exacting" work ethic of an ambitious young builder in Brisbane in the early 1900s.

Manuel Hornibrook was just 19 when he started his own building company as a way of supporting his single mother and six siblings, four of whom became his apprentices.

"There was no leeway," said his granddaughter Julie Hornibrook, who now lives near Lismore in northern New South Wales.

"If things weren't right, they just had to be done again and that was really how they built up their ethos of the company."

Ms Hornibrook said her grandfather soon moved beyond building houses to building bridges, and the company constructed more than 100 bridges including the Story Bridge in Brisbane and Sydney's Iron Cove Bridge.

Manuel Hornibrook's building company won the construction contract for the Sydney Opera House.(Supplied: Julie Hornibrook)

But it was the iconic Opera House "sails" that would prove to be Manuel Hornibrook's greatest legacy.

As the family story goes, Manuel Hornibrook said, "it would be egotistical of me to say that no-one else could build those sails, but offhand I can't think of anyone else who could".

Ms Hornibrook said while structural engineer Ove Arup had been credited with bringing the vision of architect Jorn Utzon to fruition, the practical realities of the radical design's construction fell to Hornibrook.

In 1962, when the company was awarded the construction contract, Manuel Hornibrook was 69 years old.

He leaned on his right-hand man Corbet Gore to run the project as chief engineer, with up to 10,000 workers employed throughout the construction.

"There was a lot of problem solving to be done and a lot of time pressure," Ms Hornibrook said.

It was Corbet Gore who travelled to America to source the tiles and epoxy resin that would be used to cover the sails.

Corbet Gore came up with an innovative way to support the structure as it was being built.(Supplied: Julie Hornibrook)

He also travelled to France to inspect and acquire to use of what were at the time the world's strongest cranes, three of which were used during construction.

Ms Hornibrook said it was Gore who came up with the idea for the erection arch, which held in place the ribs of the structure as they were being built.

"Hornibrook had that experience of working with bridges and pre-stressed concrete, so they worked out how the actually do that."

Ms Hornibrook said 5,000 drawings by Manuel Hornibrook were unearthed in the State Library of New South Wales, and 30,000 mathematical equations were done to ensure the accuracy of the erection arch.

Julie Hornibrook says her grandfather's legacy was largely packed away with the rest of the job site.(Supplied: Julie Hornibrook)

She said her research revealed the project's model maker remained on site during the construction process to respond to the ever-evolving design, and workers were encouraged to offer feedback on how things were unfolding.

Ms Hornibrook said her grandfather's legacy was largely packed away with the site office and construction waste at the end of the job.

"What we see is the exquisite building that remains."

When the Opera House opened in 1973, Manuel Hornibrook had died and the name of his company had changed.

"So I think some of those Australian stories have got lost along the way," Ms Hornibroko said.

"My grandfather told his staff to look back with pride at the work they had done, and I think we as Australians should do the same."