ET3 can use any form of maglev such as Electro-Dynamic Suspension (EDS) or Electro-Magnetic Suspension (EMS), however if ET3 is to be networked it must all be built to the same standard. Most maglev systems are separate from the LEM/LEG (linear electric motor/generator) elements; but EMS can be designed to incorporate LEM/LEG functions. Both EDS and EMS require significant amounts of energy to overcome magnetic drag or electrical resistance of the coils. In many cases the magnetic drag and/or suspension energy is greater than the energy to overcome rolling resistance of steel wheels carrying the same load.
With ET3 there is little or no need for powerful LEM/LEG after the capsule is up to speed, so it is best to design the maglev and LEM/LEG components to function separately).
A new form of maglev is HTSM (High Temperature Superconductor Maglev). HTSM uses superconductors in the vehicle and PM (permanent magnets) in the guideway. Unlike EDS, HTSM requires no motion for suspension force to be generated - hence HTSM has very low drag force (10ee-7 is typical, up to 10ee-9 demonstrated). Unlike EMS, HTSM requires no electrical energy or electronic measurement and feedback control of the suspension gap. The car sized HTSM prototype was invented and built by licensee Professors (Mr. and Mrs.) WANG Jiasu at SWJTU in Chengdu China. The prototype is capable of levitating for 7 hours consuming less than $3.50 worth of liquid nitrogen for cooling. In the vacuum environment, the heat gain can be reduced by an order of magnitude so we anticipate the maglev cooling cost to be in the range of 5 to 10 cents per hour per car sized capsule.
A significant problem remaining for ET3 is the LEM/LEG technology to use. There are several proven LEM technologies, however not all of them can be used to provide LEG function, and several require power transfer (or supply) in the vehicle element. Off-the-shelf linear synchronous motors (LSM) and linear induction motors (LIM) can both work for ET3. The problem is that the most efficient LEM/LEG is most efficient at speeds below about 400 to 500mph. The rail gun technologies (proven to 6,000 mph) do not provide LEG function, and have wear issues and/or under government military secrecy and control. SERAPHIM (developed at NASA 30 years ago) can work at low speed, and high speed too -- but demonstrated efficiency is in the high 70 low 80 range (LSMs have demonstrated up to 97% efficiency).
We believe that new designs will be capable of high efficiency over a very wide speed range, however they remain to be reduced to practice.