Sunday, October 13, 2013

Meeting Alice the TBM

Today being a fine day, and at the end of Auckland Heritage Festival, I trotted out as one of 20,000 holders of a free ticket to see Alice the Tunnel Boring Machine at Alan Wood Reserve in Mt Albert, the creator of two tunnels, northbound and southbound, over the next three years or so, part of the work on State Highway 20. Actually, the best view was this -- a large board right at the end of the 45 minute trek up hill and down dale. This at least lets you see what the business end of Alice looks like, the part that pumps in foam and cuts through the resulting slurry at -- wait for it -- 8cm per minute. According to the poster I picked up from an info tent, that's the top speed for a snail.

So, after winding through a snaky crowd-control path (the NZTA and Well-Connected Alliance must have taken tips from banks and the airports), we were off to see Alice. The name given to the TBM by a local school pupil who won a prize, after Alice in Wonderland.

Past a once-again altered Oakley Creek ...

On down the path through which, one day, cars and other vehicles will hurtle.

There's Alice -- well, the back end of Alice, where all the engines are, plus space for the 16 crew. The info poster says Alice needed to have a female name because of St Barbara, the patron saint of miners, tunnellers, artillerymen etc. Except that St Barbara has been removed from the Roman Catholic calendar since 1969, her story of martyrdom and association with lightning most likely a bit of Dark Ages storytelling. So, Alice the TBM is named after a fictional character due, most likely, to another bit of fiction.

I also expected Alice to be bigger.

It's the height of a four-storey building, they said on the poster. Largest TBM ever used in Australasia, weighing 3000 tonnes, the weight of 750 elephants, almost as long as a footy field ...

But ... I expected it to be something more. Even on a human scale, it doesn't look all that massive, not really.

This is a piece of artwork called "Te Haerenga Hou", "designed for the project by Auckland Ta moko artist Graham Tipene, "Te Haerenga (meaning "A New Journey) depicts the route along the volcanic landscape of what is now SH20 to the feet of Owairaka where the tunnels begin. At over 14m in diameter it is the same size as Alice's cutting face," according to a site map we were given today.

The spoil conveyor, where the resulting slurry is taken away from the tunnel, to Wiri where it'll be de-slurried and used for fill elsewhere.

It was cool, though, that they let members of the public sign these concrete launch segments, which will be used to line the tunnel. Yes, my name's on there now, too.

So, up around the corner, back out to Hendon Ave and a free bus to Mt Albert shops (and a Sunday-inconvenient -- at the moment -- train service. I took the bus back towards New Lynn.)

I'm glad I went, but -- I'm still underwhelmed.


  1. From one who missed out on a ticket: thanks - and perhaps I didn't miss out on much after all. And the talk of foam raises questions for me: what's in it? Presumably not good old Sunlight dishwashing liquid. I wonder how toxic it is?

  2. They didn't get into that. All they said on the day was -- the foam gets injected into the ground in front of the machine, chewed up as slurry, pumped out behind, trucked out,they drain the soil and then use the non-foamed soil elsewhere. By the looks of things, Onehunga's new beaches could be an area. I've been invited with a Whau Local Board member friend of mine to go to the launch this week. I'll see if they come up with anything further.