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The Evolution of Tunnel Boring Machines

construction-physics.com

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Re: The Evolution of Tunnel Boring Machines

#61

Post by bluGill »

foota wrote: post #56
Animats wrote: post #51

Little or no mention of the back end of the machine. The front end, where cutting takes place, gets all the attention. The segment placing arm got a mention. But most of the length of the machine does other things. The usual TBM setup has a two-track narrow gauge railroad behind it. Segment cars bring ring segments forward, and muck cars remove the spoil. Track cars bring more railroad track. Tool cars and worker car…

Just curious, if the rails are such an issue, is it not just cheaper to drive the cars (no need for self driving?) or is paying someone to do it not worth the complexity savings? Or are there other downsides to not having the rail?

A tunnel is round, driving cars on that and passing is hard. Narrow tunnels especially

Re: The Evolution of Tunnel Boring Machines

#62

Post by Animats »

foota wrote: post #56
Animats wrote: post #51

Little or no mention of the back end of the machine. The front end, where cutting takes place, gets all the attention. The segment placing arm got a mention. But most of the length of the machine does other things. The usual TBM setup has a two-track narrow gauge railroad behind it. Segment cars bring ring segments forward, and muck cars remove the spoil. Track cars bring more railroad track. Tool cars and worker car…

Just curious, if the rails are such an issue, is it not just cheaper to drive the cars (no need for self driving?) or is paying someone to do it not worth the complexity savings? Or are there other downsides to not having the rail?

Either each car needs a driver or you need something to keep all the trailers precisely lined up. One new system has that; a human drives the "locomotive" and the trailers have automated steering to follow the lead vehicle precisely enough to not bump into traffic in the other direction. This is still experimental.

At the other end of the line, outside the tunnel, there's a whole rail yard. The different kinds of cars have to be sorted out, loaded, and unloaded. So there's a need for a big staging area.

Here's an overview of traditional tracked systems.[1] I've tried to find a video of the back end system and yard, but nobody seems to make such videos. It's too boring.

[1] https://www.robbinstbm.com/products/tunnel-boring-machines/b...

[2]

Re: The Evolution of Tunnel Boring Machines

#63

Post by bluGill »

jcims wrote: post #17

Sometimes when I'm stuck in construction traffic I wish someone would invent the Highway Widening Machine. A machine that in one fell swoop can grind, grade, prep, pour and paint a new lane into a road.

We need a lot more than one more lane. Traffic continues at high speeds long after it isn't safe. You are supposed to see 2 seconds between cars, yet when I get on a busy road and do that I often see 5 cars in the lane next to me in that distance. Little des moines where I live needs Huston levels of lanes to allow for safe travel. For a city with significant population you need a lot more.

Or of course better public transit. The vast majority of what people are driving for could be done without driving if transit was better.

Re: The Evolution of Tunnel Boring Machines

#65

Post by andbberger »

bluGill wrote: post #63
jcims wrote: post #17

Sometimes when I'm stuck in construction traffic I wish someone would invent the Highway Widening Machine. A machine that in one fell swoop can grind, grade, prep, pour and paint a new lane into a road.

We need a lot more than one more lane. Traffic continues at high speeds long after it isn't safe. You are supposed to see 2 seconds between cars, yet when I get on a busy road and do that I often see 5 cars in the lane next to me in that distance. Little des moines where I live needs Huston levels of lanes to allow for safe travel. For a city with significant population you need a lot more. Or of course better public…

car travel would be a lot less appealing in throughput if subject to the same stringent separation requirements as rail travel.

Re: The Evolution of Tunnel Boring Machines

#67

Post by ThePowerOfFuet »

Animats wrote: post #62
foota wrote: post #56

Earlier quoted context omitted.

Just curious, if the rails are such an issue, is it not just cheaper to drive the cars (no need for self driving?) or is paying someone to do it not worth the complexity savings? Or are there other downsides to not having the rail?

Either each car needs a driver or you need something to keep all the trailers precisely lined up. One new system has that; a human drives the "locomotive" and the trailers have automated steering to follow the lead vehicle precisely enough to not bump into traffic in the other direction. This is still experimental. At the other end of the line, outside the tunnel, there's a whole rail yard. The different kinds of car…

>It's too boring.

I see what you did there.

Re: The Evolution of Tunnel Boring Machines

#68

Post by Retric »

kiba wrote: post #58
mschuster91 wrote: post #53

Earlier quoted context omitted.

> It’s worth remembering when doing inflation calculations just how poor people used to be. And also, how much of the wealth created by the employees ended up in their pockets vs. the pockets of the owners, and how the standards of living were. Basically, back then with such a job you could afford a place to live, to have kids, a wife to take care of housework and, post 1930-ish, a car. Today? Most of my generation s…

Lifestyle inflation, urban planning, and choices makes living a quality life more difficult than it should be. You're able to afford a larger house and a car or two, but you're also spending more money than necessary on transportation and housing. Buying a car is expensive and so is the road built for cars. Trains are more expensive than a car, but its cost can be amortized across many riders. Housing is a problem of…

Lifestyle inflation is why people don’t feel so much wealthier than their grandparents, but housing isn’t the economic drain it seems like because so much of its value doesn’t require resources to create. It’s mostly redistribution of income from workers to other people and as such it gets into politics.

Well that and the giant ball of suck associated with long commutes, but I am kind of hoping there’s going to be more pushback on that due to people working from home during COVID. Even those who still needed to go in had vastly less traffic.

Re: The Evolution of Tunnel Boring Machines

#70

Post by ofrzeta »

sschueller wrote: post #69

Here is a very interesting video of the challenges of digging a new pump station tunnel at a steep angle and all the unknown difficulties that can show up. https://youtu.be/6AV2NcyX7pk?si=cGvHD4eUp6zQSef2

+1 for that video. I've discovered it accidentally and was blown away. Then I watched the other videos by Marti Group and was continued to be impressed. Unfortunately they don't have many videos on YT (there are not many projects of that size I guess)
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