Paul Hogan (of Crocodile Dundee fame) used to paint it. Its the world's largest steel arch bridge. Its made of 52 800 tonnes of steel, with six million rivets holding it together.

The Sydney Harbour Bridge

Along with the Sydney Opera House its the most recognisable thing about Sydney.

They built a quarry, a settlement, and three ships just to carry the granite for the pylons at each end of the bridge. About 18 000 cubic metres of granite was mined at Moruya, about 300 kilometres south of Sydney. Each granite block was cut, dressed, and numbered, and then taken to Sydney in one of the three ships built just for the job.

250 stonemasons and their families lived in a temporary village at Moruya for the duration of the job. The bridge took 8 years to build

When it was opened in March 1932 the then Premier of New South Wales Jack Lang was upstaged by a Captain Francis de Groot who came charging through on his horse and slashed the ribbon with his sword before Mr Lang had a chance to cut it!

The arch itself is just over half a kilometre long (503 metres), and the whole bridge is more than twice that at 1149 metres. When they designed it they left 49 metres underneath so ships can easily pass through. The Bridge deck is a massive 49 metres wide, and has a six lane roadway down the middle which carries 100 000 vehicles a day. On the western side there is a train line, as well as lanes of traffic, and on the eastern side there is is a pedestrian walkway.

Did you know?

Before they opened the bridge in 1932 they tested it by parking 96 steam locomotives on it in various configurations. There were no problems, and the bridge has worked well ever since

Though it is a beautiful structure, the Sydney Harbour Bridge requires constant maintenance. When they put the first three coats of paint on it, it took 272 000 litres to do it. The bridge has to be repainted all the time - its a constant job. As soon as they have finished they start again. Thats why Paul Hogan had a job there - painting the bridge!

They have even devloped a special paint for the job. It dries out within a few seconds so that any paint drops are dry by the time they get to the cars far below!

Length of arch span

503 metres

Height of top of arch

134 metres about mean sea level

Height to top of aircraft beacon

141 metres above mean sea level

Clearance for Shipping

49 metres

Height of Pylons

89 metres above mean sea level

Width of deck

49 metres

Base of each abutment tower

68 metres across and 48 metres long (two pylons rest on each abutment tower)

Total length of bridge

1149 metres including approach spans

Bearing Pins

Each of the four pins measures 4.2 metres long and 368 millimetres in diameter

Thrust on bearings

Under maximum load approximately 20,000 tonnes on each bearing

Number of rivets

Approximately 6,000,000

Largest rivet

Weighed 3.5kilograms and was 395 millimetres long

Longest Hanger

58.8 metres

Shortest Hanger

7.3 metres

Total weight of steelwork

52,800 tonnes including arch and mild steel approach spans

Weight of arch

39,000 tonnes

Rock excavated for foundations

122,000 cubic metres

Concrete used for bridge

95,000 cubic metres

Granite facing used on pylons & piers

18,000 cubic metres

Allowance for deck expansion

420 millimetres

Allowance for arch expansion

The arch may rise or fall 18 centimetres due to heating or cooling

Number of panels in arch

28, each 18.28 metres wide

Record tonnage erected

589 tonnes of steelwork was erected on the arch in one day on 26 November 1929

Paint required

272,000 litres of paint were required to give the Bridge its initial three coats.

Strewth! Thats a big Pin!
4.2 metres (thats 14 foot!) long and 368 millimetres (14 and a half inches) thick.
There's four of them to hold the whole thing up.
But then they need to be big - they hold up twenty thousand tonnes each!