what is the significance of the opening of the harbour bridge between the wars?

Answer 1

I assume you mean the Sydney Harbour Bridge, which opened in 1932.

It was significant for several reasons.

The bridge linked Sydney and its North Shore, which had virtually operated as separate cities until that point. The only way across previously was by boat, harbour traffic was chaotic and accidents quite common.

More significant than the fact that it was between the two wars, was the fact that it was the middle of the Great Depression. The construction of the bridge provided thousands of jobs for working Australians. The opening of the bridge instilled public confidence in the engineering capabilities of their country. The celebrations for opening the bridge were a much-needed burst of fun for a city on tough times.

Answer 2

The Harbour Bridge was a major engineering achievement and provided much-needed employment to hundreds of Australian men during the more than seven years it took to build it.

During the depression it earned the nickname of the "iron lung".

Environment Minister Malcolm Turnbull, who Sunday named the bridge a national heritage item which cannot be altered, said the steel-arched structure was a reminder of the nation's strength in the face of adversity.

"The bridge was completed right in the middle of Australia's darkest days," Turnbull said.

"Australia had been bled dry by the First World War, flattened by the Great Depression, and for the nation to create this extraordinary bridge right in the centre of our most important gateway city is like an adrenaline shot of confidence for a nation that had been on its knees."