Akld harbour bridge could fail says official report

**SpankMe** · 14th October 2007, 07:31

Yep, the nippon clip-ons could fall off. Thats it, I'm sticking to the center bit from now on.

http://www.nzherald.co.nz/section/1/...ectid=10469771

**NZsarge** · 14th October 2007, 07:35

Originally Posted by SpankMe

Yep, the nippon clip-ons could fall off. Thats it, I'm sticking to the center bit from now on.

http://www.nzherald.co.nz/section/1/...ectid=10469771

Pfft!, screw it! whack up a new one, government got enough in spare change to do that

.

**Swoop** · 14th October 2007, 07:41

They want to blame the trucks, but they should look at the fully loaded busses during rush hour (a full bus in Auckland

). They are quite heavy as well.
Ban all traffic from the clip-ons! BIKES ONLY!

**peasea** · 14th October 2007, 09:00

Originally Posted by SpankMe

Yep, the nippon clip-ons could fall off. Thats it, I'm sticking to the center bit from now on.

http://www.nzherald.co.nz/section/1/...ectid=10469771

Add that to the growing list of reasons to leave Auckland...............

**Beemer** · 14th October 2007, 09:02

Originally Posted by peasea

Add that to the growing list of reasons to leave Auckland...............

Or never go there in the first place...........

**merv** · 14th October 2007, 09:05

Yep we all remember this http://www.kiwibiker.co.nz/forums/sh...ad.php?t=54733

Why weren't we like the Aussies? When they built their coathanger they built it tough, originally carrying 4 railway tracks too, now down to 2 railway tracks with the rest filled up with road lanes and you never hear them bleating its not strong enough.

In NZ we always do things on a low budget with no allowance for future growth and limit ourselves from the start. The roads are as bad, as all of us that use River Road in Upper Hutt well remember.

**davereid** · 14th October 2007, 09:06

The trouble with that bridge is its North of Auckland. So even if it does fall down the Aucklanders can still come this way...

**The Pastor** · 14th October 2007, 09:13

Originally Posted by Swoop

They want to blame the trucks, but they should look at the fully loaded busses during rush hour (a full bus in Auckland

). They are quite heavy as well.
Ban all traffic from the clip-ons! BIKES ONLY!

Its not the weight, its the type of loading - the susspension on trucks does the most damage.

also a lot of people walking over it (at once) will do the worse damage.

**Disco Dan** · 14th October 2007, 09:18

Well i'll be riding with my arm bands on now....

**jrandom** · 14th October 2007, 09:30

Originally Posted by merv

In NZ we always do things on a low budget with no allowance for future growth and limit ourselves from the start.

Aye, it's a bit like that.

It all boils down to the initial specification of the clip-ons, really. I wonder what numbnuts decided to under- rather than over-specify them?

I personally can't imagine building a bridge that wasn't designed to handle twice the maximum conceivable load (in this case, a traffic jam consisting of nothing but heavy trucks). Obviously the original engineering team didn't take that approach.

**Swoop** · 14th October 2007, 09:58

Originally Posted by jrandom

I personally can't imagine building a bridge that wasn't designed to handle twice the maximum conceivable load (in this case, a traffic jam consisting of nothing but heavy trucks). Obviously the original engineering team didn't take that approach.

I seem to remember, in the dim and distant past, there was an American involvement in the design of the bridge. The yanks said "Build an eight lane bridge!" but they were ignored and we had a nice, narrow, four-lane bridge.

I do believe the Americans' have built quite a few bridges' and possibly know what they are talking about.

**Scouse** · 14th October 2007, 10:31

Originally Posted by Swoop

I seem to remember, in the dim and distant past, there was an American involvement in the design of the bridge. The yanks said "Build an eight lane bridge!" but they were ignored and we had a nice, narrow, four-lane bridge.

I do believe the Americans' have built quite a few bridges' and possibly know what they are talking about.

they have also had quite a few bridge failiures including one this year

**jrandom** · 14th October 2007, 10:33

I feel pretty safe saying that bridge building, in the general case, is a solved engineering problem.

The only reasons a bridge will fail are incompetence in design, under-specification, or criminal negligence during its construction.

Under-specification appears to be the issue with the Auckland harbour bridge.

**merv** · 14th October 2007, 10:36

Add to that poor maintenance - allowing corrosion etc - which is what it sounds like happened in Minneapolis.

Also at the time the Auckland clip-ons were developed welded steel box girders were quite new and the design technology around them not that well developed. The most well known failure was the West Gate bridge in Melbourne which fell during early construction http://en.wikipedia.org/wiki/West_Gate_Bridge

These days I would hope computer modelling has overcome any risk of this kind of failure but that assumes the designers do it right. That doesn't help Auckland of course, you've still got old stuff.