Hmmm, I like autonomously hauling containers through tunnels as an application for Tesla.
* Could this application use battery chemistries unsuitable for other transportation applications?
In most cases and areas underground, temperatures are stable and relatively benign (there are exceptions
) so a narrower operating temperature range might be acceptable. The distances are probably mostly short and weight may be less of a factor, so the energy density requirements might be lower. Rapid acceleration and highish speeds might make power density the more desirable characteristic.
* Could it create an early entry point for the Tesla Network? It’d be a good way to encourage citizens and regulators to get warmed up to the idea of autonomy. Probably no or minimal regulatory approval needed — it is presumably a private way. Of course, the Boring Company could also run the vehicles.
* Tunnels are protected from the elements, so minimal protection is needed on the transporter. Perhaps just a skateboard as this suggests. This opens up lots of possibilities for utilizing volume for components (other than current rate limiting battery supplies) and possibly sharing lines while not taking up a lot of design cycles and logistics bandwidth.
All in all a nice application especially if other battery technology or capacity can be used.