Passenger transport system, ultralight, contactless and powered by a U-shaped linear motor.

Air cushion system issued from the Bertin Aérotrain project .
On-board traction by U-LIM linear motor with high efficiency/power factor
Air cushion (U-TRACE) or electromagnetic (FULTRACE) guidance system.
Lightweight and compact elevated track made of ultra-high performance fibre concrete.
Commercial speed: 150 km/h (U-TRACE), 300 km/h (FULTRACE).
Capacity: 80 seats per vehicle, convoy of 2 to 5 vehicles.

By using autonomous driving technology, the lane signalling system is significantly reduced, the operating system offers a fully automatic and flexible mode of transport, mixing programmed synchronization with high and low traffic periods, taking into account the « transport demand ».

U-TRACE is a zero-CO2 contribution system in its operational mode, which can also be combined with a track-integrated solar power generation concept, to achieve full energy sufficiency.

The challenge of U-TRACE is to provide an elevated track at the most competitive cost possible compared to conventional ground transport solutions. To achieve this goal, 3 major technologies must be combined:

  • Very light vehicle concept using aeronautical technologies (car shell material, ultralight saddle, …)  
  • Air cushion sustentation allows the mass of the vehicle to be evenly distributed along the track with very low pressure, greatly reducing mechanical stress
  • Contactless traction and braking system by high-efficiency linear induction motor

(1) Aérotrain – Bertin Project: https://en.wikipedia.org/wiki/A%C3%A9rotrain

U-CARS:U-LIM Containers Autonomous Railway Shuttle

U-CARS is a rail shuttle designed on the basis of a standard articulated container wagon, with 3 bogies, that offers:

  • Transport capacity: 4 20′ containers (TEU), or 2 40′ containers (FEU), considering a total payload of 105 tons on track at 22.5 t/axle, equivalent to 3 semi-trailers of 44 tons.
  • 2 electric traction systems with energy autonomy thanks to the on-board battery pack:
    • Integrated axle traction by wheel/rail contact, on each of the 6 axles of a U-CARS unit,
    • A linear U-shaped induction booster to overcome slopes greater than 2.5% up to 10%,
  • Ground contact based electrical energy system for dynamic battery charging, to increase traction power with the linear motor on high slopes
  • Concept of electric funicular for steep links, with potential energy recovery associated with a ground-based electricity storage system (case of the São Paulo-Santos rail link*).
  • Autonomous driving system based on the autonomous mobility technologies of road shuttles (obstacle detection by camera day/night, lidar-sonar, GPS location, traffic control, 4G/5G communication), with integration of online remote control system
  • Circulation in « Platooning » mode or automatic mechanical coupling to form a convoy of 2, 3, 4 or more U-CARS units, depending on the capacity response to be achieved
  • Autonomous comercial speed: 50 km/h.
  • 23/7 continuous operating mode: thanks to design reliability, redundancy of energy/traction chains and implementation of a predictive diagnostic system.

Case of the São Paulo-Santos Rail connection, the concept of « electric funicular » with potential energy recovery:

  • Power required to cross the slope of 4.5% at 54km/h and at the maximum load of 135t = 1082 kW.
  • The total theoretical duration of the entire route at a constant speed of 54 km/h is 48 minutes.  
  • The time of climbing the mountain, i.e. the distance of 18 km, is calculated in 20 minutes. 
  • The power consumption of a U-CARS to reach the climb of 18 km at 4.5% is about 400 kWh
  • The electricity recovered downhill from these 18km at -4.5% is estimated at at least 300 kWh.

=> The electric traction system in regenerative braking phases (rotary motor + linear motor) achieves a very efficient energy balance, reducing to 100 kWh max for a full round trip cycle.

U-LAUNCHER:Electromagnetic launcher for aircraft from 1 to 5 tons

The EMALS (Electromagnetic Aircraft Launch System) is an electromagnetic catapult system for military aircraft on aircraft carriers. France is committed to this choice with the USA for its new generation aircraft carrier (« PANGˮ »). In addition, the autonomy of aircraft is growing, especially with the design of heavy drones equipped for surveillance. The launch of these aircraft with a weight of 1 to 5 tons requires a runway often of more than 500 meters. Having a mobile electromagnetic catapult allowing take-off of less than 100 meters could be a strategic asset.

The recent state of the art reviewed by TACV Lab shows that the technology of the linear U-shaped motor remains very competitive to this day and by combining it with the latest technologies of power electronics and energy storage, it is possible to design a catapulting system that is very compact, efficient, durable, and at a fully controlled investment cost.