Awesome! I've got a question that I have not been able to answer. Seattle's "Big Bertha" is surplus once they finish the Alaska Viaduct project in a few months. What process could I use to establish whether or not one could use that machine locally? Assume I can get an inventory of all parts used in the machine. And a related question, is there a way to estimate the cost to retarget a used machine to a new mission?
I doubt Bertha will be purchasable given the litigation on the SR 99 job. I don't know what you would be able or want to use it for - it's 58.5 ft in diameter. It is unlikely that you will get an inventory of all the parts in the machine.
If you really want a machine then you would just call the contractor and ask them their price. You would likely have to pay for delivery.
The process to establish whether or not one could use that machine locally is just whether or not you have a job that needs a 58.5 ft diameter TBM set up the way theirs is. In other words, the process to establish whether or not one could use the machine again locally is basically to go through the design process for the tunnel (preliminary design, geotechnical exploration, laboratory testing, final design, etc.).
> I doubt Bertha will be purchasable given the
> litigation on the SR 99 job.
Can you say a bit more about this? I had reasoned that the litigation would make it more likely that Bertha would be purchasable as a way to offset costs/losses for the party that holds title to the equipment.
> I don't know what you would be able or want to
> use it for - it's 58.5 ft in diameter.
One of the longest bus routes in the Bay Area is the '22'. It travels up and down El Camino Real from San Jose to Palo Alto. El Camino Real keeps going north right up the peninsula to San Francisco. To the south it goes down to Gilroy. My proposal is to tunnel from the where it crosses Highway 152, up past Palo Alto and into Milbrae where there is both a CalTrain and BART station about 200' off of El Camino Real. My proposal would be to create bus stops along the way that took you up to the surface street of El Camino along the way. Then run bus service north south, with several different bus types "express", "local", "intercity", etc. The tunnel diameter can support four lanes of traffic (two in each direction) allowing for buses to pass one another and to support multiple schedules in the same tunnel.
Based on my evaluation of the Viaduct plan this plan would use it in substantially the same way.
Running a bit late here, but Bertha is widely considered by informed laypeople in Seattle to be the wrong solution: two smaller TBMs would have been better. The Big Bertha solution is widely considered to have been picked as a part of civic pride "a yuge tunnel!!!" rather than on engineering concerns.
I'd suggest looking at the Sound Transit "ST2" tunnel boring project, it's been massively simpler in execution.
Late indeed, is there even a tunnel in the ST2 project? Looking here: http://www.soundtransit.org/st2 was not bringing anything up with a quick parse. (search for tunnel, boring, underground all came up empty)
ST2 bored from Westlake to University of Washington, and is continuing out to the Northgate station. I'm slightly unsure how the "Eastlink" system plays out with ST2 - but they are boring around there.
That page reads like a man page, and the associated pdf's are worse! :-o
The soils vary quite significantly between the two projects with the soils up at Northlink being much more amenable to tunneling than those that plagued the SR 99 job at the start (and might at the finish).
Yeah, I've heard a bit about it, but I've not really heard enough to Know What I'm Talking About. My impression is the early phase of SR99 was running through infill from early Seattle and thus a significant amount of debris etc was involved in the problems getting Bertha going.
Do you know of any good resources on these projects for the transit / infrastructure geek who's willing to read technical information? Executive summaries and dog-and-pony documents only go so far. :)
You may be able to get the bid documents from the Owners (e.g. - WSDOT and SoundTransit) although I'm not sure. This would give you information on the soils and what the original consultants thought.
Anything past that probably hasn't come out yet since the jobs are aren't in a position where much has been published about them. If you want more information in general you can read conference proceedings (RETC, WTC, NATC).
Much of the deeper analysis and such isn't really accessible to the layman because it's really buried in the litigation.
SR 99 is likely your best bet between the two jobs because WSDOT has had an open book policy on the job. I think they've been too much of an open book, but that's neither here nor there.
Regarding the rest of your post, you would need to carry out a geotechnical investigation to see if the soils are amenable to a machine like Bertha. I would guess not, based on my experience in both areas, due to the differences in the geology.
