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The elevators in and elevators out are the bottleneck. Then inside it looks like a safety and escape hazard nightmare. What happens when someone gets a flat t

by pdq 8y ago

The elevators in and elevators out are the bottleneck. Then inside it looks like a safety and escape hazard nightmare. What happens when someone gets a flat tire?

npunt 8y ago
Seems like it needs to be centrally controlled automation so they’d be able to adjust fleet speed in relevant area for any issues that arose. Flat tire seems easy, probably a limp home mode to nearest exit + slow down nearby fleet. There should be many exits and relatively close to each other since they’re so low cost. I’m more concerned about fire & earthquake.
- haxton 8y ago
  Generally speaking tunnels are much safer than outside due to the lack of falling debris. And the fire issue is solved my any half decent sprinkler / ventilation system.
  - npunt 8y ago
    True. My concern (as a former Angelino) is what a ~2+ inch shear on the track would do to a vehicle traveling over 100mph. Lots of LA is on some fault or another that can cause these shears. Maybe it’d just be a big thud and the car goes into limp mode. Worth modeling and having risk assessment on either way.
  - youngtaff 8y ago
    Isn't water a no-go if it's a lithium battery fire?
    - MertsA 8y ago
      No, for a battery fire it's quite the opposite. It's going to release all of that stored energy and burn up the electrolyte one way or another. Flooding it with water is the best way to deal with all of that energy.
      - rini17 8y ago
        Releasing highly flammable hydrogen gas is definitely not "dealing with the energy". Both electrolysis and the reaction of water with lithium release plenty of it.
        MertsA 8y ago
        You're mistaken on that. Electrolysis is going to be far too slow to actually amount to any substantial amount of hydrogen and even if that wasn't the case burning all of that hydrogen would release only as much energy as it already took away from the reaction. Burning 100% of the hydrogen produced would still put you at a net 0 change in energy. For every joule worth of hydrogen that escaped without burning that's a joule of energy that you no longer have to deal with. Also it's a shorted out battery pack we're talking about. The voltage potential isn't going to be anywhere near as high as it would normally and if it was they you wouldn't have a flaming battery pack in the first place. As to the notion that there's lithium metal in the batteries that could react with the water, you're thinking of non-rechargeable lithium batteries. Lithium ion cells use a lithium compound, not just pure elemental lithium. The formulation might be something like LiFePO4 but the point here is that it's not just lithium metal sitting around inside of it. Also Tesla has an emergency response guide that includes instructions on fighting a battery fire. It's on page 22 (23 of the PDF) and it makes it clear that you want to douse the thing in as much water as possible and keep dousing it until it's totally gone. Tons of water is exactly what's called for when fighting these kind of fires. https://www.tesla.com/sites/default/files/downloads/2016_Model_S_Emergency_Response_Guide_en.pdf https://www.tesla.com/sites/default/files/downloads/2016_Mod...
- __s 8y ago
  Earthquakes are mentioned in the FAQ: https://www.boringcompany.com/faq/#block-yui_3_17_2_14_1494846463624_36384 https://www.boringcompany.com/faq/#block-yui_3_17_2_14_14948...
youngtaff 8y ago
Exit really is an issue… You can whizz a car along at 150mph but sooner or later its's got to leave the tunnel, the external traffic will undoubtedly be flowing more slowly so ultimately traffic is going to backup in to the tunnel

by pdq 8y ago

The elevators in and elevators out are the bottleneck. Then inside it looks like a safety and escape hazard nightmare. What happens when someone gets a flat tire?

npunt 8y ago

Seems like it needs to be centrally controlled automation so they’d be able to adjust fleet speed in relevant area for any issues that arose. Flat tire seems easy, probably a limp home mode to nearest exit + slow down nearby fleet. There should be many exits and relatively close to each other since they’re so low cost. I’m more concerned about fire & earthquake.

haxton 8y ago
Generally speaking tunnels are much safer than outside due to the lack of falling debris. And the fire issue is solved my any half decent sprinkler / ventilation system.
- npunt 8y ago
  True. My concern (as a former Angelino) is what a ~2+ inch shear on the track would do to a vehicle traveling over 100mph. Lots of LA is on some fault or another that can cause these shears. Maybe it’d just be a big thud and the car goes into limp mode. Worth modeling and having risk assessment on either way.
- youngtaff 8y ago
  Isn't water a no-go if it's a lithium battery fire?
  - MertsA 8y ago
    No, for a battery fire it's quite the opposite. It's going to release all of that stored energy and burn up the electrolyte one way or another. Flooding it with water is the best way to deal with all of that energy.
    - rini17 8y ago
      Releasing highly flammable hydrogen gas is definitely not "dealing with the energy". Both electrolysis and the reaction of water with lithium release plenty of it.
      - MertsA 8y ago
        You're mistaken on that. Electrolysis is going to be far too slow to actually amount to any substantial amount of hydrogen and even if that wasn't the case burning all of that hydrogen would release only as much energy as it already took away from the reaction. Burning 100% of the hydrogen produced would still put you at a net 0 change in energy. For every joule worth of hydrogen that escaped without burning that's a joule of energy that you no longer have to deal with. Also it's a shorted out battery pack we're talking about. The voltage potential isn't going to be anywhere near as high as it would normally and if it was they you wouldn't have a flaming battery pack in the first place. As to the notion that there's lithium metal in the batteries that could react with the water, you're thinking of non-rechargeable lithium batteries. Lithium ion cells use a lithium compound, not just pure elemental lithium. The formulation might be something like LiFePO4 but the point here is that it's not just lithium metal sitting around inside of it. Also Tesla has an emergency response guide that includes instructions on fighting a battery fire. It's on page 22 (23 of the PDF) and it makes it clear that you want to douse the thing in as much water as possible and keep dousing it until it's totally gone. Tons of water is exactly what's called for when fighting these kind of fires. https://www.tesla.com/sites/default/files/downloads/2016_Model_S_Emergency_Response_Guide_en.pdf https://www.tesla.com/sites/default/files/downloads/2016_Mod...
__s 8y ago
Earthquakes are mentioned in the FAQ: https://www.boringcompany.com/faq/#block-yui_3_17_2_14_1494846463624_36384 https://www.boringcompany.com/faq/#block-yui_3_17_2_14_14948...

youngtaff 8y ago

Exit really is an issue… You can whizz a car along at 150mph but sooner or later its's got to leave the tunnel, the external traffic will undoubtedly be flowing more slowly so ultimately traffic is going to backup in to the tunnel