Walk the bridge

Trivia question: How long did it take to build Sea Cliff Bridge?

Answer: Almost two years. A land slip closed the road in August 2003. Bridge construction started in June 2004 and finished on 11 December 2005.

Want to visit? Check out the Sea Cliff Bridge page in the official guide to the Grand Pacific Drive.

Here is a time-lapse film from The Edge Media Group on YouTube.

The article below is an extract from the South Coaster guidebook, published in December 2020. The guidebooks are $19.99 and available online, at local stores, including Collins Booksellers Thirroul, and at the Southern Gateway Centre Visitor Information Centre at Bulli Tops.

The Illawarra’s Sea Cliff Bridge echoes the curves of the coast in a concrete testament to human ingenuity.

SHORT HISTORY OF THE BRIDGE

Today the Illawarra escarpment is famous for its wild, rugged beauty and it’s formally part of the Illawarra Escarpment State Conservation Area. What early European explorers admired about the cliffs back in the early 1800s, however, were the great coal seams (hence “Coalcliff”).

The first road linking Coalcliff and Clifton was built in the 1860s – you can see the ruins of this boulder-strewn ghost track today, cutting into and around the escarpment.

Mining started in the area in 1878 and, over the next 40 years until 1918, about three million tonnes of coal was extracted from Coalcliff Colliery. Rock falls were common in the old days – signage on the bridge explains how when weak layers of coal were eroded in the cliffs, the other layers of clay, stone and sandstone formed an unstable overhang until – crack! – it broke off and a boulder smashed down from a great height .

In 1947, the road became Lawrence Hargrave Drive, named after the Stanwell Park inventor and aeronautical pioneer.

The original road was often closed as rain, erosion and weathering caused rock falls and mud slides. Then in August 2003, a big embankment slip shut it altogether.

That put the stopper on the famous Sydney to Gong bicycle race and caused serious problems for local residents and businesses, who were cut off from schools, shops and the tourist trade.

Necessity was again proved the mother of invention and construction of a new road began in June 2004 – this time an ingenious bridge over the sea, safe from falling rocks and earth.

It was a massive project, involving hundreds of people, 11,000 cubic metres of concrete and $49 million. The bridge was built in two parts: the southern end using a balanced cantilever method, while the northern section was incrementally launched.

Building finished ahead of schedule on 11 December 2005.

Grown-up innovation stalled here and a competition to name it was handed over to primary school students, who delivered the goods. Makenzie Russell, a then 11-year-old at St. Brigids, came up with Sea Cliff Bridge.