The city is awash with construction and none more visible than the works for the City Rail Link. Most of the work so far has been to move services out of the way so that the tunnels can be built without breaking something – and there are a lot of services to move. The biggest of these tasks is to divert a deep stormwater main along Albert St which involves using a micro-tunnel boring machine (MTBM). To divert it they first need to access it and the works for this have been going on behind hoardings on Victoria and Wellesley streets to dig shafts to launch and receive the MTBM.
Last week Patrick and I were kindly given a tour of these sites to see the progress so far.
The first stop was to the site on Victoria St on the Eastern side of Albert St. This is the most prominent site as there is a building over it covered in acoustic panels to help reduce noise for the site’s neighbours. This is also where the MTBM will be launched from.
The shaft is around 18m deep and the stormwater pipe has been partially uncovered. Work is now going on to find the location of the brick lined Orakei sewer main which is a little bit deeper and expected to be roughly below the feet of the worker that can be seen at the bottom of the shaft. These mains run east-west under Victoria St and the base of the Aotea station will be at about the same depth as that stormwater main – hence why it needs to be moved.
The new main to be built will connect directly into the stormwater main that can be seen above so before that happens a siphon will be built to temporarily divert it so the MTBM launched straight through the existing pipe. The spoil from the site is hoisted out via a gantry crane built into the acoustic building. Work on the site runs for 20 hours a day although trucks only remove material during the day to avoid the noise of trucks reversing. At night the spoil is stored on site.
I also noticed they’ve taken a lot of care not to damage the trees on Victoria St.
One quite unusual aspect of this worksite is its location next to the reverse bungy site. A few times while we were there were suddenly loud screams as people were hurtled into the air. I can’t imagine hearing screams is something you’d normally want on a construction site, especially one which consists of a giant hole.
On the western side of Albert St another, slightly smaller but a bit deeper shaft is also being built, but his one doesn’t have the acoustic panels.
While we were there steel was being lowered into the shaft which is used to support the pile walls as they get deeper.
Next we moved up to Wellesley St where the MTBM will be bored to. The shaft here is quite different in being much smaller and is effectively a concrete pipe being pushed into the ground via the weight of the concrete and some hydraulic jacks. It had been going fairly smoothly has been a bit tougher with about half a metre to go. At the bottom of the shaft you can see three workers digging out that last half metre or so by hand in what must be some real back breaking work.
The hydraulic jacks that help to push the shaft deeper.
In addition to looking at the works around Albert St, we also took a look at works going on behind Britomart for the temporary entrance being built so the old Chief Post Office can be closed while tunnel works go on beneath it. This is more of a conventional building site, concrete foundations have been poured and framing is going up for the various facilities that need to be housed. Steel framing has also started to go up. Inside Britomart the gardens that were on the platform level have been removed (that large pile of dirt you can see) and we were told they were in the process of removing the tiles from curved walls next to the lifts (now behind the black curtain). Of interest they said the design has been modified to take into account the huge growth we’ve been seeing on rail services in the last few years.
Finally, a few views from the office of the CRL team. This is the Commercial Bay site where piling work is already under way in some sections and the final parts of the old mall should be coming down shortly.
This is of the Albert and Customs/Fanswhare St intersection. Despite being considerably narrowed down and northbound traffic on Albert St completely stopped, it doesn’t appear to have cause any major issues for traffic. At the top of the shot you can see the huge Soilmec SR-100 piling rig that will be used for walls of the CRL tunnels up Albert St. The first piles should be started soon.
All up it was a fascinating tour showing just how much work is being done to just to prepare for the CRL. Thanks to Auckland Transport and our tour guides Scott and Jenny.