Elon Musk has been talking about hyperloop
for a while now… in the vaguest possible terms. Until now, because he’s released a
57 page document explaining his plans via his SpaceX website…
If you’re not familiar with Musky, he’s been involved or come up with paypal, tesla electronic
cars, the SpaceX programme, which came up with the world’s first reusable rockets and
designed the Falcon rocket system for Nasa, he’s invested heavily in solar energy… basically,
he’s had more great ideas than I’ve had hot dinners.
His plans for Hyperloop would involve linking two urban areas, probably no more than 1,500
kilometres apart, with a low pressure pneumatic tube-type system sending pods carrying people
from town to town at close to sonic velocity… That’s very fast.
Musk’s proposals would built a route between Los Angeles and San Francisco…
Now, if you just had a tube full of air with pods travelling through it, that wouldn’t
be quick, the friction would make the sorts have speeds he’s talking about impossible.
There have been similar plans released previously that by Rand Corporation and ET3 that would
be even quicker but would use electromagnetic suspension and a total vacuum… but the problem
is leaks – one seal or small crack on a huge tube network would stop it working.
Musk’s solution is a low pressure system, not a no pressure system, which could cope
with small leaks but would introduce another problem – the Kantrowitz limit.
Kantrowitz limit In basic terms… If the walls of the tube
and the capsule are too close together, the capsule would push the air in the system as
not enough of it would be flowing past. A bit like pressure build up in a syringe…
So you either go really slowly or have a really wide tube and travel really fast, and subject
yourself to crushing g force as soon as you go into the slightest bend.
But again Musk’s got a solution – to put a battery powered electric compressor fan at
the front of the pod pumping the air to the back and relieving the pressure…
He reckons that would work when combined with an external linear electric motor – the same
sort you’d get in an electric car, but flattened – which would accelerate the pods up to full
speed and give them a power boost every now and then.
So that would be ridiculously expensive right? Well… Elon Musk reckons he it could all
be built for several billion dollars… which he says is still cheaper than the proposed
high speed rail link in california by several factors…
his proposal is to build an elevated tube network on pylons alongside an existing highway…
that would provide a straight line, relatively few land disputes and be built in prefabricated
sections. And on top of all that he says his plans would
be more resistant to earthquakes and thermal expansion and contraction… oh, and it would be self-powering – by putting solar panels
on the tubes. Sounds perfect… but obviously there are
So Elon Musk’s proposals – if they can become reality would be safer, faster, cheaper, more
environmentally friendly, weather-proof, earthquake resistant, and less disruptive than current
modes of transport… So, I hope he really can pull it off… I also hope he designs
us all hoverboards at some point.