Sensational-Adelaide.com

Politically it could cost Labor a lot of votes in two of their most marginal seats, Bright and Mitchell. People wont be impressed about the wasting of money to demolish a brand new station. A road bridge just makes so much more sense.

metro wrote:Politically it could cost Labor a lot of votes in two of their most marginal seats, Bright and Mitchell. People wont be impressed about the wasting of money to demolish a brand new station. A road bridge just makes so much more sense.

You can only work within the budget you have. Rail bridge cheaper, quicker and less if any compulsary acquisitions required, unlike a road bridge. If money was no issue then an underpass would be on the cards, but it is.

metro wrote:Politically it could cost Labor a lot of votes in two of their most marginal seats, Bright and Mitchell. People wont be impressed about the wasting of money to demolish a brand new station. A road bridge just makes so much more sense.

I sent an email to the project team saying pretty much the exact same thing - Nothing about the Labor seats, but the other bits.

mattblack wrote:You can only work within the budget you have. Rail bridge cheaper, quicker and less if any compulsary acquisitions required, unlike a road bridge. If money was no issue then an underpass would be on the cards, but it is.

how is the rail bridge cheaper? the ramps at either end have to be longer because trains can only climb a certain grade, also the structure has to be far stronger than a road bridge, trains are much heavier, and if that train is doing 100+km/h it has to be even stronger again, thus greater cost. The rail bridge would require the demolition of a band new station and the clearing of a lot of significant trees, a road bridge would save the band new station and allow most of those significant trees to remain standing.

I've seen it done both interstate and overseas, sticking a bridge over the rail lines is the quickest and cheapest way to go. For grade separations that benefit the road users, it should be the road users that suffer the inconvenience of construction (which is what a road bridge would do), not make rail users suffer the inconvenience of construction for the road users benefit.

One of the biggest costs in building a road bridge, IMO, is associated with buying the properties / compensating the owners along the western side of Diagonal Road just north of the rail crossing. Apart from this, the bridge would need to have a bend in it, which adds to cost, and several streets (Railway Tce, Morphett Rd (northern part), Addison Rd) would lose their connection to Diagonal Road. The rail bridge makes far more sense to me, although I admit it's a pity the station has only recently been built.

rhino wrote:One of the biggest costs in building a road bridge, IMO, is associated with buying the properties / compensating the owners along the western side of Diagonal Road just north of the rail crossing. Apart from this, the bridge would need to have a bend in it, which adds to cost, and several streets (Railway Tce, Morphett Rd (northern part), Addison Rd) would lose their connection to Diagonal Road. The rail bridge makes far more sense to me, although I admit it's a pity the station has only recently been built.

There is no good reason to build it on the western side of Diagonal Road when there's so much free space on the eastern side!

But it's in a primarily residential area, and an overpass (rail or road) would be rather noisy. The station was designed to be compatible with an underpass, and that's what they should build.

Aidan wrote:

rhino wrote:One of the biggest costs in building a road bridge, IMO, is associated with buying the properties / compensating the owners along the western side of Diagonal Road just north of the rail crossing. Apart from this, the bridge would need to have a bend in it, which adds to cost, and several streets (Railway Tce, Morphett Rd (northern part), Addison Rd) would lose their connection to Diagonal Road. The rail bridge makes far more sense to me, although I admit it's a pity the station has only recently been built.

There is no good reason to build it on the western side of Diagonal Road when there's so much free space on the eastern side!

But it's in a primarily residential area, and an overpass (rail or road) would be rather noisy. The station was designed to be compatible with an underpass, and that's what they should build.

Looks like the station wasn't built for either a rail underpass or overpass.

Rail overpass would probably be cheaper and a better option.

I had a look thorugh this site and the government's own infrastructure sites collecting info on similar projects. The rail bridge I assume would be a similar project to the tram overpass at south road, that project cost about $30m, but assuming a rail bridge has to be bigger and stronger will cost twice that, so $60m plus the $10m wasted cost of Oaklands station gives us about a $70m figure. The Mawson Interchange project including a road bridge+ station cost about $30-40m. The South Rd/Anzac Hwy road underpass cost over $120m. Lastly for a rail underpass I had to look at Melbourne with the rebuild of their Nunawading Station which is now a rail underpass, it was $120m. All of these projects took about 6-12months to build.

So from least expensive to most expensive:

Road Bridge ~$20m-$40m (including cost of property acquisitions), months of roadworks and construction delays to road users, minor disruption to rail commuters. Also $10m saved by not demolishing the 3 year old oaklands station.

Rail Bridge ~$50m-$80m, more disruptive to rail users. Little to no property acquisition. But cost includes the ~$10m wasted of demolishing the brand new Oaklands station which would probably be the same as acquiring property anyways.

Road Underpass ~$100m-$140m (includes cost of property, same as the road bridge), months of roadworks and delays to both road and rail users.

Rail Underpass ~$120m

crawf wrote: Looks like the station wasn't built for either a rail underpass or overpass.

It was built to be compatible with a road underpass. If you look at Nearmap or Google, they left space for it between the crossing and the end of the platforms.

metro wrote:I had a look thorugh this site and the government's own infrastructure sites collecting info on similar projects.

That was a good idea. What sites did you use?

The rail bridge I assume would be a similar project to the tram overpass at south road, that project cost about $30m, but assuming a rail bridge has to be bigger and stronger will cost twice that, so $60m plus the $10m wasted cost of Oaklands station gives us about a $70m figure. The Mawson Interchange project including a road bridge+ station cost about $30-40m. The South Rd/Anzac Hwy road underpass cost over $120m. Lastly for a rail underpass I had to look at Melbourne with the rebuild of their Nunawading Station which is now a rail underpass, it was $120m. All of these projects took about 6-12months to build.

I don't think the Gallipoli Underpass is an appropriate comparison, as that required a lot of property acquisition, whereas vacant land to the east of Diagonal Road means that this would require none. This is more like the Bakewell Underpass.

Having said that, this is one of these things where there's a choice of doing it cheap or doing it right. Doing it right involves staggering the north end so that northbound Morphett Road traffic doesn't have to cross southbound Diagonal Road traffic on the flat.

Aidan wrote:

metro wrote:I had a look thorugh this site and the government's own infrastructure sites collecting info on similar projects.

That was a good idea. What sites did you use?

this one: sensational-adelaide.com

infrastructure.sa.gov.au

and i will even admit to using the oh so reliable en.wikipedia.org

Please vote Aidan to be minister of everything people

Hooligan wrote:Please vote Aidan to be minister of everything people

The Mugabe of Sensational Adelaide. If he doesnt agree with you he'll beat you into submission with Aidan factoids.

metro wrote:I had a look thorugh this site and the government's own infrastructure sites collecting info on similar projects. The rail bridge I assume would be a similar project to the tram overpass at south road, that project cost about $30m, but assuming a rail bridge has to be bigger and stronger will cost twice that, so $60m plus the $10m wasted cost of Oaklands station gives us about a $70m figure. The Mawson Interchange project including a road bridge+ station cost about $30-40m. The South Rd/Anzac Hwy road underpass cost over $120m. Lastly for a rail underpass I had to look at Melbourne with the rebuild of their Nunawading Station which is now a rail underpass, it was $120m. All of these projects took about 6-12months to build.

So from least expensive to most expensive:

Road Bridge ~$20m-$40m (including cost of property acquisitions), months of roadworks and construction delays to road users, minor disruption to rail commuters. Also $10m saved by not demolishing the 3 year old oaklands station.

Rail Bridge ~$50m-$80m, more disruptive to rail users. Little to no property acquisition. But cost includes the ~$10m wasted of demolishing the brand new Oaklands station which would probably be the same as acquiring property anyways.

Road Underpass ~$100m-$140m (includes cost of property, same as the road bridge), months of roadworks and delays to both road and rail users.

Rail Underpass ~$120m

I guarantee that a rail bridge is the cheapest and quickest option, based on a more scientific method than an internet search. Road bridge not an option because it will cause access issues to businesses and homes on Diagonal Rd and southern Morphett Rd. DTEI have had a close look at this.

Should be a similar project to the South Road tram overpass. Not too many dramas in distrupting the Rail traffic if they want it to still keep it going. Aquiring the properties between Diagonal Road and the road behind it towards the Railway station would increase parking and improve bus interchange connections.

Westfield would be wise to contribute as it would improve relations for commuters and shopping centre staff.

Cheers.

Ray.

I suggest go for the super expensive should-have-been-done-decades-ago option... Start off running the bulldozers on to a few properties south of the train station, 1.) because first we need to clear some space for the workmen smoko huts and guard dog kennels, and 2,) hell, because I always enjoyed destroying homes with the bulldozer on Sim City 2000 and hearing that explosion sound.

As the corner of the tracks meet at Morphett/Diagonal road, instead of them meeting, make them continue on and rise up high up into the air and in opposite directions, at a height of about 400 metres. Then, please just imagine the catchy Sim City 2000 music playing as you are picturing this.... then the tracks would swing around in a circle in the air hovering over the marion shopping centre. The new train station can thus be at Marion Shopping Centre and lifts can take people to the elevated train station. Slippery Slides can be provided for exiting passengers (you could even have a slide going all the way down to the pool at the new Aquatic centre).

This has added benefits that:

A.) it will appeal to tourists because it's like a roller coaster in space.

2.) will avoid people paying exorbitant soon to be introduced westfield parking fees by providing direct quick and easy access via train.

C.) start the opening day up with a wet t shirt contest, with the lovely ladies covered in suds washing the brand new trains. Babes must be 18-19 years as Kevin Foley will be judging, must have backup judge when Foley's girlfriend appears on stage.

4.) Could also add in a corkscrew and a water pit.

Estimated budget of my plan, well factoring in costs of a similar project in Victoria, and the relative costs of corkscrews in the popular sim game Roller Coaster Tycoon, I estimate the total cost to be about $35 million, give or take a few million.