24-m opportunity-charged electric BRT




Modernisation of the Busway BRT line in Nantes


Nantes métropole




As part of the modernisation of the Busway BRT line, Nantes Métropole wanted to operate 24-m, double-articulated electric vehicles on the line, with recharging on the tracks and at the terminals (opportunity charging). This will be the first system of its kind in the world. Nantes Métropole appointed SEMITAN to manage the project.

Goal of the mission

Transamo provided SEMITAN with its technical and legal expertise, initially for the preparation of the tender enquiry documents.


Expertise in operational problems through the technical analysis of the study results and the proposals made by SEMITAN on:

  • the modelling of the routes for the construction of the simulation reference standard
  • the operation of the Porte de Vertou terminus
  • the time available for charging in stations
  • degraded modes

Expertise in network and access way problems through the technical analysis of the study results and the proposals made by SEMITAN on:

  • the adaptation of the line for the unimpeded operation of the 24-, bi-articulated buses
  • integration of charging equipment in the stations (connections, charging units)

Expertise in the vehicle-related problems by providing technical assistance for:

  • the study of the energy consumption of the vehicles on Line 4
  • the drafting of the specifications of the vehicles and analysis of the bids
  • identification of any adaptations of the parking facilities and workshops due to the new vehicles

Expertise in energy-related problems by providing technical assistance for the following studies:

  • recharging the buses in the parking zone
  • energy consumption profile of the charging units in the stations
  • the power level of the charging units
  • connection with the network and relations with the concession holder
  • possible energy management innovations (e.g., smart grids)
  • the energy efficiency of the complete system

Expertise in legal problems:

  • the form of the acceptable bids in the tender process
  • identification and assessment of risks
  • funding the bus batteries and the fixed electricity storage systems
  • clauses to be considered in order to benefit from advances in battery technology in the medium term
  • the essential regulatory formalities (extra-large buses, installed electrical capacity in the stations and the technical and operations centre)