Sea Cliff Bridge

Background

Sea Cliff Bridge is located on the coast of New South Wales, south of Sydney, between the small coastal towns of Coalcliff and Clifton.

It forms part of Lawrence Hargrave Drive, a road that extends from Helensburgh to Thirroul, which was named in 1926 after inventor, aeronautical pioneer and explorer, Lawrence Hargrave.

Longstanding rock fall problems had been experienced on Lawrence Hargrave Rd between Coalcliff and Clifton due to the road at that time being positioned right next to the cliff and in 2002 the problem became acute resulting in the road being permanently closed.

The rock debris was dropping from the steep cliff hovering above the cliff hugging road, particularly after rain.

A bridge that would be located some distance from the cliff was seen to be the answer to the problem of rockfalls.

Although the NSW Government initially had some reservations about building a bridge to replace the existing road in view of the cost, environmental concerns and geotechnical issues, it was decided to go ahead.

Construction began at the start of 2004 and the bridge was completed in December 2005.

Some parts of the former road can still be seen if you visit Sea Cliff Bridge particularly at the south end.

A rusted cream guard rail shows where the road was located. Part of the underpinning sandstone wall supporting the old road has collapsed and bushes have overgrown other parts of the former road.

New bridge(s)

Two bridges were in fact necessary to remedy the situation. Sea Cliff Bridge is up to 70 metres from the cliff in places and provides for plenty of room should a rockslide from the cliff eventuate.

It is easy to miss the first bridge, Lawrence Hargrave Bridge, as you drive south past Coalcliff. In fact you may not even think you are driving on a bridge, but rather a new piece of road.

Lawrence Hargrave Bridge measures 210 metres and was incrementally launched.

Incrementally launched bridges are built in segments in a casting bed. The segment is pushed out of the casting bed across the obstacle to be crossed. The casting bed may then be used to make another segment.

The bridge is made from one side only. They are commonly used where there are access problems or to minimize disruption at ground level and the spans generally do not exceed 60 metres.

The second bridge, Sea Cliff Bridge, is a balanced cantilevered bridge and 450 metres long.

This type of bridge is more suitable for longer spans and will typically consists of two cantilever arms that extend in opposite directions from a single support.

Why visit

The design, engineering and aesthetics of Sea Cliff Bridge are what make it so attractive.

When you first see it in the distance you are drawn to have a second look at a roadway suspended above the ocean that curves with the contours of the surrounding cliffs.

The curves and flow of the bridge gracefully fit in with the rugged surrounding environment. Both bridges, Lawrence Hargrave and Sea Cliff Bridge were built in difficult environments.

The challenging environment consisted of sea on one side, steep cliffs on the other, underlying coal seams and very little available land.

The construction of both bridges in such a situation is a fine engineering achievement.

If you visit don’t just drive over the bridge, park just beyond where the bridge finishes in the south, and take a walk.

It is a pleasure to walk along the bridge and enjoy the views of the ocean, the nearby dramatic cliff and the several large rock platforms that can be seen below.

Put this one on your list!

Be Imperial

And if your in the mood for a little more try The Imperial at Clifton for a coffee, cold drink or something to eat. This hotel has been sympathetically renovated maintaining its historical features, has lots of natural light and broad ocean views.

It is only a few hundred metres down the road heading south.