Each unit weighs . The body is long, wide and tall. The center distance between the bogies is and the center wheel distance in the bogies is . The wheel diameter is —this is larger than the Re 460. The El 18 has a Knorr HSM mechanical braking system, but unlike the Swiss versions does not have a rail brake. The design of the locomotive was by the Italian company Pininfarina. The machine room is designed with a center aisle, the driver's cabs have pressurization applied to avoid air pressure dropping when running through tunnels, and the cabs are equipped with air conditioning.