Wednesday, May 21, 2008

Ok...

So why does the proposed tunnel under Jaffa Harbour cost over $1 billion. And Transmission gully cost $700 million+?

When this cost E394 million just a few years back.

In another socialist basket-case country.

7 comments:

Seamonkey Madness said...

Os,

Shifting dirt out of a tunnel is a pretty expensive operation, not that constructing span bridges isn't mind you. Chalk and cheese though, you must admit.

RMA wouldn't help but...

libertyscott said...

Several reasons:
1. New Zealand is seismic, France isn't. Transmission Gully is on a fault line (with a viaduct crossing it), Auckland is a city built on a dozen volcanoes.
2. Tunneling in Auckland is very expensive because of the rock, it is hard and expensive to move. Sydney is the opposite.
3. Transmission Gully is steep both sides, with Ngauranga Gorge inclines, but three times as long.
4. Milau Viaduct was done as a commercial project by the private sector financing and building it, recovering the costs by high tolls, most motorways in France are operated by government or privately owned companies. In New Zealand Transit is a Crown entity, it has no profit motive, but every motive to escalate costs when projects are politically motivated.

Oh and Transmission Gully is over $1 billion. The politicians/bureaucrats who talk about it forget that the costing was done in 2004/2005 and inflation means those values are over $1 billion now.

Sus said...

OB, did you see the doco on Prime last Sunday night, too? Magnificent to watch the Millau bridge under construction and how the engineers resolved the issues.

What a beautiful structure.

sweetpea said...

Auckland is built on over 40 volcanoes. The type of rock changes in the space of metres with the depth and type of suface cover over the greywacke rock the whole lot sits on varies from clay to basult to scoria to tuft to mud and sand.
The old Mangere Bridge is a good example, all the piles were built on solid rock, an old lava flow, but the rock under one pile turned out to be only a metre thick. After several years the pile punched through to the mud beneath.

Oswald Bastable said...

Sus- I saw it- it is an amazing structure!

ALL these cutting edge structures have major engineering challenges- that was my point.

An alternative for Transmission gully was a raised roadway along the coastline. Far less challenging than the Milau Viaduct, but way more expensive.

Sure, we have geological problems here with NZ being one big fault line, but a viaduct was successfully built at Arthur's Pass. It's certainly do-able- as was thew Wellington motorway, also along a major fault.

The RMA is the real millstone around the neck...

Johnboy said...

The tunnel under Jafa harbour has a very expensive large bathplug in the middle of it and I have the other end of the chain.

Oi said...

€394 million is around 1.2 billion NZ, isnt it?
Fairly expensive for a 2 kilometre bridge!