[alexose]

The original stated goal was to 10x the speed of existing tunnel boring machines by bringing up the cutting head RPMs, automating liner installation, and speeding up spoil removal with electric sleds. Which would seem like a good bet, except that there are a million other bottlenecks to the process. On top of that, it doesn't seem like they even solved their core problems.

It would be cool if they'd post a postmortem or something, but I get the impression that reporting bad news is a good way to get fired in an Elon-run organization.

[screye]

Much like the Hyperloop before it, the core assumption of the Boring company is ill-conceived. Tunnel boring isn't a bottleneck.

The costs of surveys, hvac, seismic research and maintenance required to keep a deep-underground tunnel going are much higher than cut-and-cover. So, even if tunnel boring was free, it still wouldn't make sense to prefer it over other options. There are very scenarios where deep-tunneling makes sense (dense cities, across rivers when bridges are infeasible), but they're the minority.

In most transit projects, cut-and-over is blocked not because it's a bad technical option. It's because NIMBYs refuse to permit on-the-ground disruptions or noise of any type. San Jose is the canonical example. It's a political problem, not a technical one.

[bryanlarsen]

My impression was that the main "innovation" was using sewer tunnel sized tunnels for cars. We already know how to build sewer tunnels relatively cheaply and quickly.

[quickthrowman]

I’m not sure why anyone believed this load of lies, tunnel boring is a mature industry with multiple companies that make tunnel boring machines, and tunnel boring has been around for well over a hundred years. The cutting heads move slowly because they’re between 3 and ~50 feet in diameter (1 to 15 meters for non Americans)

Anyone claiming they can 10x the speed of a physical process that has been worked on by thousands of engineers over more than a century is full of shit. Anyone who bought that explanation is either far too credulous or just doesn’t understand what it takes to bore a large diameter tunnel.

[jstanley]

> Anyone claiming they can 10x the speed of a physical process that has been worked on by thousands of engineers over more than a century is full of shit.

Metal machining processes had been around for well over 100 years when tungsten carbide tooling came along, and that increased cutting speeds by 10x over HSS. It happens.

[XorNot]

Sure but no one founded companies saying they were going to do exactly that until they actually had tungsten carbide tooling in hand and it was a production engineering issue.

What technology or research was the Boring company sitting on that it expected to utilize to get this advantage?

[potato3732842]

You can't actually assess these things without hindsight. At any given time there's a dozen promising looking things but most of them never work out.

Lithium batteries were "coming soon" for like 30yr.

[XorNot]

Which isn't the question: what promising things was the Boring company looking at? Not what they said they wanted to achieve, how were they planning on doing it?

Lithium batteries at all points were quite specific "we think <process> will reduce costs and make them viable".

[quickthrowman]

Tunnel boring is only partly about boring the tunnel itself, bracing the tunnel and removing the spoils probably take as much time as boring the tunnel itself.

It’s a complex process with work crews, management layers, multiple subcontractors, multiple stakeholders, etc. Replacing the tool on a CNC mill with a tungsten carbide tool takes what, a few minutes? Assuming you already have the tool.

It’s also insanely easy to verify a tungsten carbide CNC tool is 10x faster at cutting metal than high speed steel vs. testing ‘This tunnel boring machine will be 10x faster.’

One takes minutes, the other takes years.

[9cb14c1ec0]

Space launch is a mature industry with multiple companies. Anyone who thinks SpaceX can lower the launch costs by orders of magnitude is either far to credulous or just doesn't understand what it takes to launch a rocket.

[quickthrowman]

NASA procurement was (is?) full of pork barrel politics meant to provide jobs in as many states as possible. I would expect a lean private organization to easily beat NASA in cost per launch. What SpaceX has done is very impressive, I have a lot of respect for what they’ve accomplished.

Space travel is also far less mature than tunnel boring technology, I’d expect advances in space travel before tunnel boring because there’s low hanging fruit. Space travel used to be done only by nation-states, only in the last 25-30 years has private space travel been possible. Tunnel boring machines were invented 200 years ago and were useful about 150 years ago.

[titannet]

Wasn't that the OPs argument? Companies have been building tunnel after tunnel [..] and optimized the process. No one had tried to large scale industrialize satellite + space launcher production before.

[orwin]

Space launch still isn't a mature industry, what are you talking about?

[DrewADesign]

I get the sense that the goalposts get moved to wherever he kicks the ball, even retrospectively. His whole vibe feels like he’s just real-life cosplaying Ironman.

[Terr_]

While ending closer to a hapless Justin Hammer.

https://www.youtube.com/watch?v=v3JCdchkNSY&t=9m53s