The number of pods per hour is related only to the distance between city pairs (distance dictates your top speed, which determines your pod spacing, more or less). However, the length of the pod does not factor proportionally into energy required. That means that you could build a 3 system setup:
1) Compressor Section – unfortunately required to get around the Kantrowitz choking limit
2) Power Supply – this would go in the back, and would be responsible for powering propulsion and compressor (as well as control, etc).
3) Passengers – the center sections, capable of powering their own life support, entertainment, etc.
Since passive magnetic levitation gets easier as you stretch the pod “train” (longer means you can put more magnets on), that means you are using proportionally less energy every time you add another passenger car. You probably design the battery section for the longest allowable train (let’s just call it 5 passenger cars), plus a margin of safety.
You’re now sending 5 cars through at the same pod spacing as before. A production design would likely aim for the 24-30 passengers per car range. Let’s call it 28.
So, let’s do some math.
For the city pair that lets you get to 760 mph, let’s assume that you have an emergency braking of 1g. That requires about 34 seconds to get from full speed to a dead stop. In that 34 seconds, the pod travels about 3.7 miles. That gives you how much room you need to safely stop if the pod in front of yours is stationary. We’ll round up to 4 miles just to give you buffer and to make the numbers nicer.
The route designed by SpaceX for the SF/LA city pair is about 360 miles. That means that at any given time, you should be able to fit 90 pods into the tube (with another about to enter). If it takes their estimated 35 minutes to travel, this means that you are launching a pod every 23 seconds. That’s a little insane. Let’s make it every 5 minutes to allow for loading/unloading, airlocks, etc (if you have something like an assembly line similar to a lot of amusement park rides – picture the setup for loading a raft ride, you can do everything simultaneously and cut that down to under a minute). That’s 7-8 pods in the tube at any given time.
Converting that to pods per hour, 5 minute spacing with our assumed pod train size translates to 1820 passengers per hour. 1 minute spacing brings that up to 8400 passengers per hour. HSR is about 9600 passengers per hour (from Eurostar), at 800 passengers per train.← Frequently Asked Questions