Saturday, April 14, 2012

Day 13 of 30 Days of Biking: Oh the places you can go on a bike!

The day started with a ride to the University of Washington for a most-of-the-day meeting with the visiting committee of the College of Engineering.  It ended about five stories down in a hole for a tour of the unfinished University and Capitol Hill stations and tunnels of the Light Rail system.  Mike, the project manager for the University side of the tunnel, gave an excellent tour.  His family has been in the mining business for generations and he is doing the modern version of it--with twin tunnel boring machines (TBM),  the tips of which look like this:

The tip of the TBM seen from the Capitol Hill Station.  The tunnel is in the background.  The rest of the boring machine is still in the tunnel.
Here is a closer view of the boring tip, along with project manager Mike.
To get a good look at the machines, we did a lot of climbing ladders and ducking under things.


Once inside the machine, there is room to move around. The total length of the TBM is about 330 feet, about the length of a football field.

Traylor, the company who build the University side of the tunnels, finished four months early.  Here is what the roughed-in tunnel looks like.


As the TBM advances, they construct the cement tunnel lining behind it like a jigsaw puzzle.  They then use the lip of the liner to push against to advance the TBM.

Tunnel lining.

After tour, we climbed back out of the hole.


Mike says that people don't think about tunnels much.  I think that that is true. I know that I'll think of Mike, the miners, and the machines that built them each time I go through a tunnel.

Let's Roll!
Donna
Seattle, WA

P.S. When I returned to my bike, here is what had happened.



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