Sea Cliff Bridge

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Sea Cliff Bridge
Sea Cliff Bridge from air.jpg
The Sea Cliff Bridge viewed from the air
Coordinates34°15′14″S 150°58′26″E / 34.25389°S 150.97389°E / -34.25389; 150.97389Coordinates: 34°15′14″S 150°58′26″E / 34.25389°S 150.97389°E / -34.25389; 150.97389
CarriesLawrence Hargrave Drive
(also known as Grand Pacific Drive)
CrossesRockface on the Illawarra escarpment/Tasman Sea
LocaleCoalcliff, Illawarra, New South Wales, Australia
BeginsCoalcliff
EndsClifton
Other name(s)Lawrence Hargrave Drive Bridge
OwnerTransport for New South Wales
Characteristics
Design
  1. Balanced off-shore parallel-to-coast cantilever bridge
    (Sea Cliff Bridge)
  2. Incremental launching girder bridge
    (Lawrence Hargrave Drive Bridge)
MaterialSteel reinforced concrete
Total length
  1. 455.6 metres (1,495 ft)
    (Sea Cliff Bridge)
  2. 210 metres (690 ft)
    (Lawrence Hargrave Drive Bridge)
Width6.3 metres (21 ft) at its widest point
Height41 metres (135 ft) at highest point
Longest span
  1. 3 x 108 metres (354 ft)
    (Sea Cliff Bridge)
  2. 5 x 31 metres (102 ft)
    (Lawrence Hargrave Drive Bridge)
No. of spans
  1. 5 (Sea Cliff Bridge)
  2. 7 (Lawrence Hargrave Drive Bridge)
No. of lanes2
History
Contracted lead designerMaunsell Australia
Engineering design byCoffey Geosciences
Constructed byBarclay Mowlem Construction
Construction end9 December 2005 (2005-12-09)
Construction costA$52 million
Inaugurated11 December 2005 (2005-12-11) by
Morris Iemma, NSW Premier
Location
References
[1][2][3]

The Sea Cliff Bridge, together with the adjoining Lawrence Hargrave Drive Bridge, are two road bridges that carry the scenic Lawrence Hargrave Drive across the rockface on the Illawarra escarpment, located in the northern Illawarra region of New South Wales, Australia. The balanced cantilever and incremental launching girder bridges link the coastal villages of Coalcliff and Clifton and carry two lanes of traffic, and a pedestrian walkway. The Sea Cliff Bridge is one of only seven off-shore parallel-to-coast bridges in the world.[4]

The Sea Cliff Bridge was named by Makenzie Russell, who at the time was an eleven-year-old student, following a naming competition opened to local primary school students.[5] The Lawrence Hargrave Drive Bridge and the Lawrence Hargrave Drive are named in honour of Lawrence Hargrave, an Australian engineer, explorer, astronomer, inventor and aeronautical pioneer.

History[edit]

The Sea Cliff Bridge replaced a section of Lawrence Hargrave Drive that was permanently closed in August 2003 due to regular rock falls. A public outcry emerged over the road closure as Lawrence Hargrave Drive is the only road directly linking Coalcliff, Stanwell Park, Otford and Helensburgh to the northern suburbs of Wollongong.[6]

Description[edit]

The A$52 million 450-metre-long (1,476 ft) bridges brace against the Tasman Sea, up to 70 metres (230 ft) east of the original alignment of Lawrence Hargrave Drive. Completed in 2005, the Sea Cliff Bridge structure comprises a haunched box girder composed of prestressed concrete that was constructed using the balanced cantilever method, with five spans.[2] Adjoining the Sea Cliff Bridge is the 210-metre-long (689 ft) Lawrence Hargrave Drive Bridge – often not considered as two separate bridges. This latter girder bridge that was constructed using the incremental launching method, with seven spans, ranging from 24 to 31 metres (79 to 102 ft), shares a common pier with the Sea Cliff Bridge.[3]

The bridges incorporate two traffic lanes of 3.5 to 3.8 metres (11 to 12 ft) and a 2.5-metre (8 ft) pedestrian pathway.[7] Cyclists are allowed to use the traffic lanes and there are shoulders on either side of the road of approximately 1.2 metres (4 ft) width.

The bridges were officially opened by the NSW Premier Morris Iemma on 11 December 2005, and were met with public approval and increased business for the area's tourism industry.[6]

The bridges sit in a harsh marine environment as it directly faces the open ocean and is affected by high sea swell splashing. It is well attested that concrete structures in such environments are especially susceptible to chloride induced corrosion of the steel reinforcement, which can eventually lead to expensive repair works and significantly decrease the life of the structure.[4][8]

Tourism[edit]

An hour south of Sydney, the bridges have been a major tourist spot since they opened in 2005.[9] The area adjacent to the bridges feature a scenic walkway surrounded by rocky cliffs[4] that is a popular location for love padlocks.[10]

The iconic bridges have drawn an increasing number of tourists in the late 2010s due to social media and bushwalking blogs online.[citation needed] Pioneer Walks published the route to the lookout and encouraged spectators to participate in an "unofficial walk with no safety precautions in place".[11] On 30 September 2018, a 24-year-old man hiked to the “lookout" atop the cliff overlooking the bridges, where he sat down to take a rest. The ground he sat on was loose, and he slid 20 metres (70 ft) to the cliff’s edge, where he then plummeted 40 metres (130 ft) to his death.[12]

The Seacliff Bridge Grand Pacific Drive, New South Wales, Australia May 2020

In popular media[edit]

The Sea Cliff Bridge and adjoining Lawrence Hargrave Drive Bridge were featured in a range of media including:

Gallery[edit]

See also[edit]

References[edit]

  1. ^ "Bridge Construction Statistics". Sea Cliff Bridge. Retrieved 23 May 2009.
  2. ^ a b Sea Cliff Bridge at Structurae. Retrieved 8 April 2020.
  3. ^ a b Lawrence Hargrave Drive Bridge at Structurae. Retrieved 8 April 2020.
  4. ^ a b c "APPLICATION OF CATHODIC PREVENTION TO SEA CLIFF BRIDGE, LAWRENCE HARGRAVE DRIVE" (PDF). Retrieved 3 October 2018.
  5. ^ "Makenzie who?". Sea Cliff Bridge. Retrieved 2 February 2013.
  6. ^ a b "Why Was It Constructed?". Sea Cliff Bridge. Retrieved 23 May 2009.
  7. ^ "Sea Cliff Bridge". Projects. Boral. n.d. Retrieved 8 April 2020.
  8. ^ Sinclair, M. R (2005). "Lawrence Hargrave Drive balanced cantilever and incremental launch bridges construction". Concrete (5).
  9. ^ "Sea Cliff Bridge". Destination Wollongong. 2020. Retrieved 8 April 2020.
  10. ^ Minus, Jodie (13 March 2009). "Sea Cliff Bridge holds key to love". Illawarra Mercury. Retrieved 1 September 2011.
  11. ^ "Sea Cliff Bridge". Pioneer Walks.
  12. ^ Humphries, Glen (5 February 2019). "Bushwalking site promotes the deadly Sea Cliff Bridge walk". Illawarra Mercury. Retrieved 8 April 2020.
  13. ^ https://www.youtube.com/watch?v=E4Fg-mj2DCE
  14. ^ https://www.youtube.com/watch?v=6GuTkJh4N5c
  15. ^ https://www.youtube.com/watch?v=O-i0mG67Uaw
  16. ^ https://www.youtube.com/watch?v=G9xXMGzW8NY

External links[edit]