What’s your thinking there? The bigger tunnel boring machines needed and the extra dirt excavated are cheap in the bigger picture. The trend is clear within London alone and globally, towards larger tunnels.
Vegas hyperloop was <30 million per mile, so somewhere between 3% and 0.6% the cost per mile.
Reportedly, in this expansion, private companies will carry the entire cost.
At the end of the day The boring company seems to be able to avoid these high costs using a combination of their technology, simplified goal, and business approach while nobody else has been able to bring costs down for a large tunnels in the US.
It would be great if someone could figure out how to bring large Tunnel cost down in the US, but until someone does, smaller tunnels costing a few percent of the cost have a competitive advantage.
My understanding is that the problems driving large tunnel construction costs in the US are driven by a shortage of labor expertise, Labor bloat compared to other countries, and institutional inability to manage large projects and avoid scope change.
This understanding is not correct. America's tunneling cost problem is driven by labor costs, unions, politics, and third party litigation. The institutional inability to manage large projects is a result of the latter three of these: the people in charge when the contract is signed are often not the people in charge when the job is half completed, and that change in leadership leads to scope changes that should (justifiably) be paid for.
I agree third party litigation warrants highlighting, but I consider that as part of institutional inability to manage large projects.
Likelwise, I see high labor costs and unions as equavalent to lack of skilled labor and bloated labor costs.
At the end of the day, we are saying the same thing. Cost of workers is higher, the US uses far more workers, and the US legal and political systems are not condusive to efficient execution.
For example, the labor shortage impacts all construction in America but tunnels require even more specialized laborers. Unions drive up the cost of all construction in America, but specific unions (like the Sandhogs) have specific provisions in their contracts that drive up the cost even more. Scope changes impact all construction, but scope changes underground cost orders of magnitude more than surface scope changes (add an offramp above ground versus add an offramp underground). Third party litigation impacts all construction, but the nature of tunneling increases the risk of third party litigation because settlement/sinkholes can occur vast distances away from the work.
Where I disagree is that the boring company is approach minimizes the magnitude and impact of these challenges.
For example, if the project scope isn't dictated by politicians, it is less susceptible to political whims and scope changes.
If the project scope is smaller, the we all challenges will be fewer. If the tunnels are smaller, service requirements are lower.
It would be interesting to know the boring company uses union labor or not.
I'm not sure what you mean by service requirements for a tunnel, but I assume you mean maintenance. Maintenance requirements for tunnels are only tangentially related to diameter once the final lining is in place, it is mostly driven by length. Realistically there is only so much maintenance that can happen for a tunnel or for any underground structure from the structural perspective since you can't look outside of the tunnel from the inside. So you overdesign. Maintenance requirements thus amount to visual inspections of the inside and maintenance of appurtenant mechanical/electrical systems. These mechanical/electrical systems become more reliable and more efficient with relation to tunnel diameter, and so your maintenance requirements actually decrease on an aggregate basis (i.e. - a tunnel that can support 2 lanes of traffic is less costly to maintain than 2 tunnels that support 1 lane of traffic).
And the idea that anything ran by Elon Musk is not susceptible to whims and scope changes is laughable.
I was first asking why they thought small tunnels are better, is that purely on financial grounds? Low cost, low benefit.