5 ms·

One question I couldn't see answered in the FAQ is what happens if one of the electric skates breaks down? Given each of the skates is independently driven, th

One question I couldn't see answered in the FAQ is what happens if one of the electric skates breaks down? Given each of the skates is independently driven, the chance of failure would be magnified by N, for N skates within a tunnel. Seems like failures could be quite common and would affect the entire tunnel?

mdekkers 8y ago
Seems like failures could be quite common How did you come to this conclusion?
- NuclearFishin 8y ago
  It's more of a guess than a conclusion. Because the tunnel is linear, the failure of a single skate affects the entire line, so running, say, 100 skates concurrently would make overall failure 100 times more likely. One option is to make the skates incredibly fault-tolerant, but that seems to go against the simple / cheap ethos that this system seems to be going for.
  - kibibu 8y ago
    Just to make this more concrete, if your skate platform breaks down just once every 10 years, then banging 100 skates in the tunnel will see this breaking down at about once a month or so.
    - secabeen 8y ago
      If you have a flat failure curve, sure. If you have the more traditional bathtub curve, after the initial problems, failure rates should be much lower.
indecisive_user 8y ago
How is that problem any different than other single track transportations (subway, train, trolley)?
- NuclearFishin 8y ago
  Perhaps it's not, but my gut feel is that those other systems mitigate failure by using a smaller number of large, reliable and expensive carriages. Whereas this system is going for a large number of smaller, cheaper(?) skates. It just feels like it's more susceptible to failure?
  - VectorLock 8y ago
    Design the skates so that one can push another at reduced speeds. Bang, built in redundancy.
    - trainmew 8y ago
      How will the skates know that the one in front of it has broken down and need to be pushed? Especially when it's operating at 120mph?
      - donkeyd 8y ago
        Sensors in the tunnel and the skates, that communicate with each other? It's not rocket science, that's how it's worked for years with trains and subways and even car tunnels have continuous monitoring and signage to alert other drivers.
      - trainmew 8y ago
        Yes, I know that. That now means you need a way for the skates to communicate with each other and maintain a safe distance from each other before they collide and obviously slower speeds. That bare concrete tunnel is now longer bare since you will need communication access points, fibre cables for redundancy, etc.
        VectorLock 8y ago
        They're going to be running cables for lights. Its not much of a stretch to put in communication cabling as well. It makes sense to have the skateboards fully connected as part of their 'autonomy.'
gamegoblin 8y ago
For the most common types of failure that aren't safety issues, I imagine the skate behind the broken one could push it (of course at a much slower speed).

mdekkers 8y ago

Seems like failures could be quite common How did you come to this conclusion?

NuclearFishin 8y ago
It's more of a guess than a conclusion. Because the tunnel is linear, the failure of a single skate affects the entire line, so running, say, 100 skates concurrently would make overall failure 100 times more likely. One option is to make the skates incredibly fault-tolerant, but that seems to go against the simple / cheap ethos that this system seems to be going for.
- kibibu 8y ago
  Just to make this more concrete, if your skate platform breaks down just once every 10 years, then banging 100 skates in the tunnel will see this breaking down at about once a month or so.
  - secabeen 8y ago
    If you have a flat failure curve, sure. If you have the more traditional bathtub curve, after the initial problems, failure rates should be much lower.

indecisive_user 8y ago

How is that problem any different than other single track transportations (subway, train, trolley)?

NuclearFishin 8y ago
Perhaps it's not, but my gut feel is that those other systems mitigate failure by using a smaller number of large, reliable and expensive carriages. Whereas this system is going for a large number of smaller, cheaper(?) skates. It just feels like it's more susceptible to failure?
- VectorLock 8y ago
  Design the skates so that one can push another at reduced speeds. Bang, built in redundancy.
  - trainmew 8y ago
    How will the skates know that the one in front of it has broken down and need to be pushed? Especially when it's operating at 120mph?
    - donkeyd 8y ago
      Sensors in the tunnel and the skates, that communicate with each other? It's not rocket science, that's how it's worked for years with trains and subways and even car tunnels have continuous monitoring and signage to alert other drivers.
    - trainmew 8y ago
      Yes, I know that. That now means you need a way for the skates to communicate with each other and maintain a safe distance from each other before they collide and obviously slower speeds. That bare concrete tunnel is now longer bare since you will need communication access points, fibre cables for redundancy, etc.
      - VectorLock 8y ago
        They're going to be running cables for lights. Its not much of a stretch to put in communication cabling as well. It makes sense to have the skateboards fully connected as part of their 'autonomy.'

gamegoblin 8y ago

For the most common types of failure that aren't safety issues, I imagine the skate behind the broken one could push it (of course at a much slower speed).