The Canberra library has ­released 40,000, out-of-copyright maps in what it claims constitutes the world’s biggest library of free digitised historical maps.

The surveys date from the late 15th century to 50 years ago and include the vast — maps of the globe — to the intimate — sketches of suburban backyards.

There is a collection of architect Walter Burley Griffin’s drawings of Canberra, there’s a Sydney tramway map from the turn of last century revealing an intricate rail system the current NSW government can merely dream of replicating.

The Japanese government funded digitisation of army survey maps of the southwest Pacific and then matched them with war diaries held by the Australian War Memorial. Library map ­curator Martin Woods said the exercise sought to locate military actions to help the repatriation of war dead.

Norman B. Tindale’s famous map showing the distribution of Aboriginal tribes of Australia is available for download.

Dr Woods said use of the collection since its soft launch at Christmas had been brisk, and in recent weeks some technological bugs had been ironed out. “Within the cartographical community this is a very big deal,” he said.

Family history researchers, property owners and even cafe decorators have mined the collection.

“We provide compressed format so anybody can download them, but if anyone wants high-resolution maps they can also do that for all 40,000 maps,” he said.

Researchers have downloaded historical maps and superimposed them over Google maps to discover historical context.

Dr Woods envisages a day when a sequence of historical maps is layered over a contemporary map to provide a multi-layered historical picture.

The biggest map in the system is of Bungendore township near Canberra, where a 3m by 4m town map was so big it had to be scanned in sections.

The library’s digital mapping project began 15 years ago and will take many more to be completed, with only 5 per cent of the entire 800,000-strong collection having been copied.

The digital map release isn’t unique to Australia; t he British ­Library has digitised 10,000 maps and the New York Public Library has released 20,000 maps.