If you like this, then you'll really like the series currently running on the BBC about the crossrail excavation - they have some great video of the TBMs in operation.
If you are in London, you might also like the Brunel Museum which is at the end of a tunnel under the river which was hang-dug using a human powered TBM. You can go down into the Rotherhithe shaft which was the staging post for a lot of the digging. The museum itself is pretty small but the guided walks are great.
Pretty cool how a project that took 10+ years to agree on is going to make traffic worse in the 4th most congested metropolitan area in the US and cost 2-5x as much. All around a fine bureaucratic job by everyone involved.
Well one alternative floated was to simply to demolish the unsafe viaduct with no replacement, as San Francisco did with the Embarcadero Freeway after the '89 earthquake. My preferred alternative, and much cheaper! However that wasn't a popular suggestion, probably because it would be worse for traffic (at least in the medium-term), especially given Seattle's not-great public transit. Another alternative is to rebuild the viaduct, which would be cheaper than a tunnel but still very expensive, and would probably require it to be closed in the interim anyway, because it basically needs a complete replacement of the unsound 1950s structure, not just more reinforcement. Or, of course, keep the viaduct as is and hope there aren't any major earthquakes...
I like Seattle's public transit. As for the tunnel, how about giving the right-of-way to Sound Transit and let them build the Ballard/West Seattle rail route through there? They seem to be doing quite well at digging tunnels pretty much everywhere.
What there is of Seattle's transit is good. The problem is that coverage is poor, it relies too heavily on buses (I'd love some more comprehensive regional rail...) and the buses are over capacity and underfunded. Otherwise it is sanitary (some other cities seem to have trouble keeping feces off of everything, but Seattle does well there) and often on time.
Seattle Transit Blog had a post that touched on that topic. (which I can't find) I think the reason to not do that is that the tunnel is too deep so you would not have stations downtown since the cost of each station is more then a transit only tunnel.
As for the last option, the viaduct is sinking, if it sinks too much they'll be forced to close it and it's already nearly half of the way there. So even if we tossed earthquake safety out the window the viaduct realistically doesn't have a long lifetime ahead of it.
I agree, that would definitely be the best option. The money could've been allocated to transit improvements which would likely diffuse some of the congestion growth. $3bn would buy you an awful lot of transit.
Yup. As a Seattle area resident it's been frustrating watching this clusterfuck play out in slow motion to the tune of billions in costs. The deep bore tunnel was the most expensive and riskiest of all the options to replace the viaduct. For a while there was hope, but it turned out to be just as much of a shitshow as most detractors imagined. The tunnel was supposed to have been open to traffic sometime in 2015. Now 2015 is when they will finally be able to dig down to the TBM so they can extract the cutting head in order to repair it, and then maybe sometime after that they can return to digging.
Is it? According to some, making more lanes makes traffic worse, according to some others, making less lanes makes traffic worse, so which is it? Can you ever make traffic less worse?
In those studies that show removing a lane can improve traffic flow or adding a lane can worsen traffic, that is only true of particular lanes/roads in different areas. In fact, it is more than likely that removing any one lane from any road is more likely to worsen traffic than it is to improve it.
It is entirely dependent on the network patterns of the traffic flow itself, not the roads.
In general, anything that encourages people to drive their own cars in cities makes traffic worse. Blocking roads can improve traffic but annoys people.
Congestion taxes, higher parking fees, improved or cheaper public transport can all make traffic better, but the first two will annoy people.
Unfortunately "big engineering" is 10% fun and 90% filling out paperwork - and with a few exceptions the paperwork part is the only bit that offers any career progression.
Documentaries rarely bother filming the 200 guys who spend years working in office parks on P6 plans and CAD models to plan everything to the Nth degree!
And even the "fun" is 90% boring. The tunneling itself is maintaining the TBM as it's doing its thing and crawling along at ~30ft/day. Seeing them in action for 10mn is fun (I did and the scale is awe-inspiring) but I'd expect working on them to be more on the boring side.
“So obviously they’re doing a lot of planning and engineering work to ensure that it will fit back in there,” he added.
Anybody that's worked with engineers had to laugh at that.
Yes, obviously they've done all the work they could possibly do. Otherwise they would be phonies. But I'll bet there's a huge difference between how this fine-detail work looks on paper an how it's actually going to happen.
How far did they get before jamming? If I recall correctly, with borers like this, they lay the concrete tunnel sections behind it as it digs, and the diameter of the finished tunnel is obviously smaller than that of the raw tunnel, which means you can't back it out without demolishing all of the tunnel sections you've already laid. The article doesn't mention any of that, unless I missed it. Were they "lucky" enough that the breakdown came before any concrete was laid?
http://www.crossrail.co.uk/news/articles/the-bbc-goes-behind...
If you are in London, you might also like the Brunel Museum which is at the end of a tunnel under the river which was hang-dug using a human powered TBM. You can go down into the Rotherhithe shaft which was the staging post for a lot of the digging. The museum itself is pretty small but the guided walks are great.
http://www.brunel-museum.org.uk/history/the-thames-tunnel/