The Canning Bridge has been linking Perth to Fremantle since 1849, and despite having to be rebuilt four times, the timber structure remains strong.

The bridge, which crosses the Canning River between Como and Applecross, is only eight kilometres from the centre of Perth.

The second Canning Bridge which lasted from 1867-1907. The surrounding area was still largely bushland. ( Supplied: State Library of Western Australia )

Yet when it was first proposed, the area was considered very remote, Richard Offen from Heritage Perth told 720 ABC Perth.

"The area was not even farmland, it was mainly bush," Mr Offen said.

"There were the beginnings of the road to Fremantle, and although the river still dominated as the main route of transport, road transport was becoming more important and more necessary.

"I think it was the need to service the agricultural areas, particularly getting stuff from Guildford down to Fremantle.

"It wasn't always convenient by river because in periods of low rainfall the river had a nasty habit of being too low for boats."

A bridge too high



The first bridge was designed by the superintendent of public works Henry Trigg in 1846.

But after tenders to build the bridge proved too high for the colonial government, the project was dropped and not resurrected until three years later.

The first Canning Bridge, built in 1849, lasted only 18 years.

"In 1862 there was widespread flooding in the Swan River catchment," Mr Offen said.

The third Canning Bridge, c1920. ( Supplied: State Library of Western Australia )

"A second Canning Bridge was built in 1867, that time using convict labour."

The bridge was notable for its steep elevation in the centre, designed to withstand flooding, but it also deteriorated slowly and lasted only 40 years.

"The state of the bridge got very critical and the state government allocated funding at the start of 1907, so Canning Bridge number three was constructed in 1908," Mr Offen said.

"It was flatter in appearance and much stronger in construction."

The timber holding up the Canning Bridge since 1939. ( 720 ABC Perth: Emma Wynne )

But the bridge had also reached the end of its life after 30 years, when the fourth and final bridge was built in 1939, adjacent to the third bridge.

"It's constructed of timber. Karri, Jarrah and Wandoo and they are fairly resistant to fire, particularly Jarrah which wears extremely well in water," he said.

"At that time they had forethought to run essential services over the bridge and they had gas mains, water mains and electricity installed.

"Concrete collars were put in place to make it even more certain that it wouldn't rot."

The fourth and final bridge

The fourth Canning Bridge was officially opened in December 1939, but the old third bridge was not demolished straight away.

The fourth Canning Bridge, with the Raffles Hotel in the background, after completion in 1939. ( Supplied: State Library of Western Australia )

"The old bridge was given a reprieve from demolition because of the outbreak of World War II," Mr Offen said.

"They were concerned that if a bomb was dropped or some espionage took place on the new bridge that they would have the old bridge to fall back on.

"The old bridge was eventually demolished in the late 1940s."

Thanks to extensive repairs and modifications, the fourth bridge has lasted longer than all its predecessors and the timber pylons have withstood the test of time, although some of the Karri had to be replaced by steel in the 1990s.

In 2012 the bridge was permanently listed on the state heritage register.

"It's still here and, judging by the amount of traffic, still giving extremely good service," Mr Offen said.