[julianozen]

Ill add to this. If you listen to his interview with Kara Swisher on recode, he has a pretty compelling case on what he thinks the established industry is overlooking. According to him, the technology used for tunneling is very outdated. The Diesel engines could be replaced by something far more powerful without hitting thermal limits reducing drill time. Current technology also fills the tunnel with exhaust that needs to be pumped out with oxygen

It’s not hard to see how trying something high powered and electric/lithium-ion based might change the cost/benefits of tunneling, and Elon/Tesla also seems like it might have a uniquely special knowledge of electric motors to succeed

I see no reason why this isn’t worth the experiment.

[corodra]

Yea, that argument makes perfect sense, if you totally ignore that the speed of tunneling isn't dictated by the drill but by installing the support structures as you tunnel. The actual tunneling aspect is not the bottleneck (unless you're doing certain mountain ranges). The bottleneck is making sure what you just drilled doesn't immediately collapse on you. Along with evacuating the material out of the way. That's the reason tunneling takes so long. You have to support the new section of hole so it does't collapse due to pressure or a damn random earthquake happens to hit. To do that too, you need to properly get rid of the material out of your way so the structure is stabilized. The drills normally (80%-90% of the time) outpace the support structure building process already. You can only go so far until you have to wait for them to catch up.

Do I agree that electricity would potentially help? Yes. Mostly for exhaust. As long as you can equal out the torque as well. Motors that large don't always have the same amount of torque as their fuel counter parts. But massive batteries overheat as well and are an explosive risks. Diesel at least needs to be well aerated to pose as an extreme fire risk. Running a large battery for that long would be an issue. You still have the heat, but at least the exhaust problems are potentially not there. Even though large lithium batteries still produce fumes when run hot. But I'm not sure as to what ppm until those fumes are dangerous/equal to carbon monoxide.

[stcredzero]

The bottleneck is making sure what you just drilled doesn't immediately collapse on you. Along with evacuating the material out of the way. That's the reason tunneling takes so long.

From what I've read, Boring Company is very aware of this. Give me a 1st principles analysis for why those things can't be done cheaper and faster?

[gamblor956]

Elon must be pretty out-of-date on his tunneling research since most of the tunneling machines in use these days are electrical, powered directly from the local grid. (Think about it--if you're running a combustible engine in a confined space the last thing you would do is flood the area with pure oxygen.)

The thermal limits in boring isn't related to the energy source--it's related to the bore head warming up from the friction of boring. This problem is addressed by cooling the bore head with water.