Talk:Auckland Harbour Bridge
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Has anyone got information on the fault with the clip-on sections, circa 1985, where traffic was limited on the clip-ons, until the structures underneath were strengthened? Also, there was a toll booth on the northern part of the motorway approaching the bridge, this was not used from what date? Mjm1964 10:07, 14 May 2005 (UTC)
- An embedded comment cites http://www.theviaduct.com/theviaduct/history/1980.asp to give 30 March 1984 when the toll boothes were removed.Tenbaset 10:49, August 13, 2005 (UTC)
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[edit] Length of Bridge
Looking on the web I don't see anything to support the current length stated as 1.15 km. Most sites report either 3348 or 3350 feet, which is 1020-1 meters. The Transit NZ document http://www.transit.govt.nz/content_files/AHB/1951-1961.pdf lists it as 3348 feet so I've taken this value. XLerate 22:01, 9 March 2007 (UTC)
[edit] Second harbour crossing
The feasibility study mentions several additional considerations including the requirement for cycling and walking options in any second harbour crossing. Cheers... Nil Einne 20:08, 3 May 2007 (UTC)
[edit] Clip Ons at risk of failure
There is an article in today's Sunday herald that states a BECA engineering report that the clip ons are at risk of imminent failure, should this be included? http://www.nzherald.co.nz/section/1/story.cfm?c_id=1&objectid=10469771 Nzv8fan 02:06, 14 October 2007 (UTC)
- Indeed. I have added it. Please have a look, you are welcome to add such material to articles on your own. Ingolfson 07:33, 14 October 2007 (UTC)
[edit] Clipon details
The following was added by an anonymous user. Until it is referenced, I do not think it should be in the article, also it is relatively specific, so there is no large loss to the article in removing it again, though I'd be happy for it to be back in a referenced and slightly condensed form. May eventually look into dredging up refs myself...
QUOTE
Design of the clip ons was by UK firm Freeman Fox. This was a thin plate box structure with stiffened panels.
Proof load checking of the clip on structures was carried out in 1972-75 for the Auckland Harbour Bridge Authority by a German firm Haensel Roik & Albrecht. Some strengthening of the structures was carried out following this detailed review. Following this work, there was agreement between the parties that the bridge was able to safely carry the traffic streams likely to be encountered but the consultant felt some reservation about full compliance with design codes for the day for the designated design live loads. An in-depth review of the findings of this 1972-75 work was carried out by MWD staff with the German consultant staff in January/February 1987. This included traffic stream assessments to obtain 1987 traffic patterns to compare with the loadings used by the German consultants assessments.
In July 1985 fatigue cracks were found in the stiffened steel deck plates on the clip-ons and extensive bridge repairs carried out on both bridges replacing the stiffener welds in the wheel paths. It was decided at that time that the stiffener welds away from the main wheelpaths had some remaining life and that similar repairs could be done to these when required. During the stiffener repairs, heavy traffic was confined to the central spans (off the clip ons) and the clip ons were closed at night to allow work to be undertaken inside the box sections. Consideration was given to keeping heavy traffic permanently off the clip on spans at this time but this decision was not taken. Recommendations were made at that time to keep all overweight vehicles (particularly those with overweight axles) off the clip on structures as a permanent measure.
A review of world wide design practice for fatigue detailing in the mid to late 1960s was undertaken during 1986 to see if the fatigue problems should have been forseen during the original design but this concluded that these possibilities were beginning to be recognised but were not well understood at that time. Working life for some similar bridge details were still being researched through full scale testing in the UK during the mid to late 1980s.
UNQUOTE
