Deadman's Point Bridge
{{Short description|Bridge in Cromwell, New Zealand}}
{{Use New Zealand English|date=April 2024}}
{{Infobox bridge
| name = Deadman's Point Bridge
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| image = Deadmans Point Bridge Lake Dunstan Cromwell.jpg
| image_size = 300 px
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| coordinates = {{coord|45|02|19|S|169|13|16|E|display=title,inline}}
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| carries = 2 lanes of State Highway 8B
| crosses = Lake Dunstan
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| owner = New Zealand Transport Agency
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| preceded = Deadman's Point Footbridge
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| material = steel
| material1 = concrete
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| length = {{convert|272| m|ft}}
| width = {{convert|12| m|ft}}
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| depth = {{convert|35| m|ft}}
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| mainspan = {{convert|40|m|ft}}
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| piers_in_water = 4
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| clearance_below = {{convert|9| m|ft}} on true left of lake
| lanes = 2
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| designer = Ministry of Works and Development
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| built = 1986
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| replaces = Cromwell Bridge
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Deadman's Point Bridge crosses Lake Dunstan at Cromwell, Central Otago, as part of New Zealand's State Highway 8 (SH8). A short spur section, SH8B, joins SH8 on the true left bank of Lake Dunstan, crossing Deadman's Point Bridge to meet State Highway 6 immediately west of Cromwell.
Background
=Etymology=
The origin of the name Deadman's Point appears uncertain,{{Cite web |title=Deadman's Point |url=https://mightyclutha.blogspot.com/2009/03/deadmans-point-bridge.html |access-date=28 August 2023 |website=Mighty Clutha}} although an early account suggests the narrow headland of schist bedrock at Deadman's Point made the Clutha River (Māori: Mata-Au) a perilous crossing:
{{blockquote|It is so-called because a man once fell from the suspension bridge which still spans the river there. He was found stiff and cold next morning, dead from heart failure. This grim story, and also the local legend that the bodies of the unfortunates who were drowned higher up the Clutha in the early days were invariably washed up at this point...|Waipukurau Press, 28(173), 19 July 1933{{Cite news |date=19 July 1933 |title=Aptly named "Deadman's Point" |volume=28 |pages=3 |work=Waipukurau Press |issue=173 |url=https://paperspast.natlib.govt.nz/newspapers/WPRESS19330719.2.18 |access-date=28 August 2023}}}}
=Clyde Dam=
Deadman's Point Bridge was built to replace Cromwell Bridge which was flooded in 1992–93 with the filling of Lake Dunstan. The Clyde Dam hydroelectric project caused the impoundment of the Clutha River at the mouth of the Cromwell Gorge near Clyde. With a head of {{Convert|60|m|ft|abbr=on}}, the Cromwell Gorge and much of Cromwell's old town was flooded, necessitating a new highway through the gorge as well as a new bridge to cross Lake Dunstan.
Construction of Deadman's Point Bridge followed a lengthy debate on where the new bridge into Cromwell should be located.{{cite book |last1=McElroy |first1=E. J. |title=An Analysis of Planning Procedures Associated with the Development of the Cromwell Town Plan |date=1982 |publisher=Otago University (PGDip Thesis) |location=Dunedin, NZ |url=https://ourarchive.otago.ac.nz/bitstream/handle/10523/11832/McElroyElissaJ1982Dip.pdf?sequence=1&isAllowed=y |access-date=30 August 2023}} Numerous options were considered during the early design phases of the Clyde Dam, including a bridge at the same location as the old bridge (but higher), two bridges connecting Cornish Point, a bridge extending from Cromwell's Neplusultra Street, and the Deadman's Point location.{{Cite web |title=Cromwell Bridge Approaches |url=https://www.codc.govt.nz/repository/libraries/id:2apsqkk8g1cxbyoqohn0/hierarchy/services/archives/archive-repository/documents/CromwellBridgeApproach.pdf |access-date=30 August 2023 |website=Central Otago District Council}}
Construction
The initial construction of Deadman's Point Bridge began in 1978 and continued until early 1982.{{Citation needed|date=August 2023}} The bridge is supported by four concrete piers, each {{Convert|11|m|ft|abbr=on}} wide,{{Cite journal |last=Skinner |first=R. I |last2=Tyler |first2=R. G. |last3=Heine |first3=A. J. |last4=Robinson |first4=W. H. |date=1978 |title=Hysteretic dampers for the protection of structures from earthquakes |url=https://bulletin.nzsee.org.nz/index.php/bnzsee/article/view/1029/1002 |journal=Bulletin of the New Zealand National Society for Earthquake Engineering |volume=13 |issue=1 |pages=22–36}} sunk into the schist bedrock either side of the (former) main Clutha River channel. Easton Industries (Napier) Ltd were charged with fabrication of the bridge's steel trusses, approximately 550 tonnes worth,{{Cite news |date=29 April 1978 |title=Cromwell Bridge at Deadman's Point - Fabrication of Steel Trusses |pages=24 |work=The Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19780429.2.173.2}} having won a tender for 288,874 NZD in 1978.{{Cite journal |date=3 August 1978 |title=Tariff Decision List |url=http://www.nzlii.org/nz/other/nz_gazette/1978/68/19.pdf |journal=The New Zealand Gazette |volume=68 |issue=19}} The total cost of Deadman's Point Bridge was 2.4 million NZD in 1984.{{Cite news |last=Thompson |first=B. |date=10 May 1984 |title=Soaring costs of new Clyde-Cromwell road |pages=21 |work=The Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19840510.2.120.1 |access-date=31 August 2023}}
Given the slope instability noted during the construction of the Clyde Dam{{Cite journal |last=O'Brien |first=G. A. |last2=Cox |first2=S. C. |last3=Townend |first3=J. |date=2016 |title=Spatially and temporally systematic hydrologic changes within large geo-engineered landslides, Cromwell Gorge, New Zealand, induced by multiple regional earthquakes |url=https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016JB013418 |journal=J. Geophys. Res. Solid Earth |volume=121 |pages=8750–8773 |via=AGU}} and the potential for earthquake-induced damage, the piers of Deadman's Point Bridge were fitted with rocking isolation hinges which allow the bridge piers to uplift and pivot during earthquake excitation. The bridge's design focuses on diminishing the structural deformation and damage caused during a seismic event.{{Cite journal |last=Giouvanidis |first=A. I. |last2=Dimitrakopoulos |first2=E. G. |date=2014 |title=Seismic Analysis of Hybrid Rocking Bridge Bents |url=https://www.researchgate.net/publication/283510502_Seismic_Analysis_of_Hybrid_Rocking_Bridge_Bents |journal=Second European Conference on Earthquake Engineering and Seismology. Istanbul, Turkey |via=ResearchGate}}
Associated with the construction of Deadman's Point Bridge was road realignment and completion of State Highway SH8B. Re-sealing of this portion of road was completed in 1985.{{Cite news |date=9 February 1985 |title=Alexandra Residency SH6 to Deadmans Point Bridge Second Coat Seal |pages=71 |work=The Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19850209.2.218.8 |access-date=31 August 2023}}
Associated development
With consented and projected residential development occurring on both sides of SH8B,{{Cite book |last=NM Associates Ltd - Architects and Planners |url=https://www.codc.govt.nz/repository/libraries/id:2apsqkk8g1cxbyoqohn0/hierarchy/your-council/project-updates/cromwelleyetothefuture/documents/Cromwell%20Spatial%20Framework%20-%20Stage%201%20Spatial%20Plan%20Report_LR.pdf |title=Cromwell 'Eye to the Future' Masterplan Spatial Framework Stage 1: Spatial Plan |publisher=Central Otago District Council |year=2019}} this portion of road will eventually become an urban through-route. It is anticipated that the speed limit will be {{Convert|50|km/h|mph|abbr=on}}, perhaps lower, for the overall distance between Deadman's Point Bridge and SH6.
References
{{Reflist}}
{{Clutha}}
{{Central Otago}}
Category:Central Otago District
Category:Bridges over the Clutha River / Mata-Au