In order to estimate the reduction of seat-specific energy consumption, conventional (2950 mm) and wide-body (3400 mm) versions of an otherwise identical train (e.g. equal length etc) are compared. These widths correspond to the conventional ICE 3 and to a wide-body ICE 3 based on a design study.

Aerodynamic effect of wider car body

The cross-section of the train is increased by ~15%. Since air resistance grows with cross-sectional area in a less than proportional way, it is safe to assume that air resistance grows in the order of 10% or less.

Mass effect of wider car body

The design study for a wide-body version ICE 3 yielded a mass increment of about 10% in comparison to conventional ICE 3 design.

Comfort functions

No data are available on the effect on the energy consumption of comfort functions in a wide-body train. For obvious reasons (less wall surface per seat, less interior space to be heated per seat etc), it is increased by less than the relative increase in seating capacity. 10% will be a safe upper limit here as well.

Energy consumption of the entire train

Since all components of energy consumption of a passenger train (mass, air drag and comfort energy) are increased by about 10% (or less), the energy consumption will also increase by 10% or less.

Seat-specific energy demand

Since seating capacity is increased by about 25%, the 110% energy consumption have to be divided by 1,25 to get the seat-specific energy demand relative to a conventional car design. The result is a reduction of seat-specific energy consumption by 12%.

Assuming that a maximum of half of the regional lines and some of the main lines could be operated with wide-body stock in long term, the applicability in most fleets will not exceed 25%, but could reach values of up to 40% in some fleets. Accordingly, this gives a maximum system-wide effect of 2 - 5 %.